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This chapter describes the equipment and site requirements for router installation. It includes the power and cabling requirements that must be in place at the installation site, descriptions of additional equipment you will need to complete the installation, and the environmental conditions your site must meet to maintain normal operation.
This chapter includes the following preinstallation requirements:
The following guidelines will help to ensure your safety and protect the equipment. This list is not inclusive of all potentially hazardous situations, so be alert.
A fully configured Cisco 7513 weighs approximately 160 pounds. The chassis is not intended to be moved frequently. Before you install the router, ensure that your site is properly prepared, so you can avoid having to move the chassis later to accommodate power sources and network connections.
Whenever you lift the chassis or any heavy object, follow these guidelines:
The network interface processors are designed to be removed and replaced while the system is operating without presenting an electrical hazard or damage to the system. However, you must shut down the system before removing or replacing the RSP2.
Follow these basic guidelines when working with any electrical equipment:
In addition, use the guidelines that follow when working with any equipment that is disconnected from a power source, but still connected to telephone wiring or other network cabling.
Preventing Electrostatic Discharge Damage
Electrostatic discharge (ESD) damage, which occurs when electronic cards or components are improperly handled, can result in complete or intermittent failures. Each processor module comprises a printed circuit board that is fixed in a metal carrier. Electromagnetic interference (EMI) shielding, connectors, and a handle are integral components of the carrier. Although the carrier helps to protect the module, use an antistatic strap whenever handling processor modules. Handle the carriers by the handles and the carrier edges only; never touch the boards or connector pins.
Following are guidelines for preventing ESD damage:
The environmental monitoring functionality in the router protects the system and components from potential damage from overvoltage and overtemperature conditions. To assure normal operation and avoid unnecessary maintenance, plan your site configuration and prepare your site before installation. After installation, make sure the site maintains an ambient temperature of 32°F through 104°F (0°C through 40°C), and keep the area around the chassis as free from dust as is practical.
The following sections address the site environment requirements for the router.
The 1200W, AC-input power supply uses a power factor corrector (PFC) that allows the Cisco 7513 to operate on input voltage and current within the ranges of 100 to 240 VAC and 50 to 60 Hz. Table 1-1 lists system power specifications, including input voltage and operating frequency ranges.
The 1200W, DC-input power supply allows the Cisco 7513 to operate between --40 and --72 VDC (--48 VDC nominal in North America and --60 VDC in Europe).
Following are guidelines for setting up the plant wiring and cabling at your site. When planning the location of the new system, consider the distance limitations for signaling, electromagnetic interference, and connector compatibility, as described in the following sections.
When wires are run for any significant distance in an electromagnetic field, interference can occur between the field and the signals on the wires. This fact has two implications for the construction of plant wiring:
If you use twisted-pair cable in your plant wiring with a good distribution of grounding conductors, the plant wiring is unlikely to emit radio interference. When exceeding the recommended distances, use a high-quality twisted-pair cable with one ground conductor for each data signal when applicable.
If wires exceed recommended distances, or if wires pass between buildings, give special consideration to the effect of a lightning strike in your vicinity. The electromagnetic pulse (EMP) caused by lightning or other high-energy phenomena can easily couple enough energy into unshielded conductors to destroy electronic devices. If you have had problems of this sort in the past, you may want to consult experts in electrical surge suppression and shielding.
Most data centers cannot resolve the infrequent but potentially catastrophic problems just described without pulse meters and other special equipment. These problems can cost a great deal of time to identify and resolve, so take precautions by providing a properly grounded and shielded environment, with special attention to issues of electrical surge suppression. The ground screw on the left side of the interface processor end of the chassis provides a connection point for connecting a ground wire or antistatic device to chassis ground. (See Figure 1-3.)
Distance Limitations and Interface Specifications
The length of your networks and the distances between connections depend on the type of signal, the signal speed, and the transmission media (the type of cabling used to transmit the signals). For example, standard coaxial cable has a greater channel capacity than twisted-pair cabling. The distance and rate limits in these descriptions are the IEEE recommended maximum speeds and distances for signaling; however, you can usually get good results at speeds and distances far greater than these. For example, the recommended maximum rate for V.35 is 2 Mbps, but it is commonly used at 4 Mbps without any problems. If you understand the electrical problems that might arise and can compensate for them, you should get good results with rates and distances greater than those shown here; however, do so at your own risk.
The following distance limits are provided as guidelines for planning your network connections before installation.
Ethernet Connections
The maximum distances for Ethernet network segments and connections depend on the type of transmission cable used: 0.4-inch diameter coaxial (10BASE-5), 0.25-inch diameter coaxial (10BASE-2), or unshielded twisted-pair (10BASE-T). The term 10BASEN is an abbreviation for 10 Mbps transmission, BASEband medium, and N is the maximum cable length in hundreds of meters.
Network connections to the coaxial cables are tapped into a network segment and must be spaced at specific intervals. Table 2-1 lists the maximum number of connections (taps) per segment and the intervals at which they must be placed. A maximum of four repeaters can be used to link segments in a single network.
Table 2-1 : Ethernet Coaxial Connection Limits for 10-Mbps Transmission
The unshielded twisted-pair (UTP) cabling used with 10BASE-T is suitable for voice transmission, but may incur problems at 10-Mbps transmission rates. UTP wiring does not require the fixed spacing between connections that is necessary with the coaxial-type connections. IEEE recommends a maximum distance of 328 feet (100 meters) between station (connection) and hub for 10BASE-T connections.
Fast Ethernet Connections IEEE 802.3u specifies several different physical layers for 100BASE-T: among them are 100BASE-TX, which is 100BASE-T, half duplex, over Category 5, unshielded twisted-pair (UTP), Electronics Industry Association/Telecommunications Industry Association (EIA/TIA)--568-compliant cable; 100BASE-FX, which is 100BASE-T, full duplex or half duplex over optical fiber; and 100BASE-T4, which is 100BASE-T using Category 3, 4, or 5 UTP or shielded twisted pair (STP) cabling with four pairs. 100BASE-T4 is also called 4T+ or T2, which is 2-pair UTP over Category 3 cable.
Table 2-2 lists the cabling specifications for 100-Mbps transmission over 100BASE-T, Category 5 UTP and MII connections.
Table 2-2 : Connection Limits for 100-Mbps Transmission
Table 2-3 summarizes the characteristics of 100BASE-T with respect to IEEE 802.3u physical characteristics.
Table 2-3 : IEEE 802.3u Physical Characteristics
Channel Interface Connections
The maximum transmission distance for ESCON (with LED) is 1.9 miles (3.1 km) point-to-point or 5.7 miles (9.2 km) with two ESCON Directors. The maximum transmission distance for bus and tag is 400 feet (122 m). The IBM 3044 C/D (host side/remote side) copper-to-fiber repeater can be used to extend the bus and tag distance up to 1.2 miles (2 km).
E1-G.703/G.704 Connections
Unbalanced G.703 interfaces allow for a longer maximum cable length than those specified for balanced circuits. Table 2-4 lists the maximum cable lengths for each FSIP E1-G.703/G.704 cable type by the connector used at the network (non-FSIP) end.
Table 2-4 : E1-G.703/G.704 Maximum Cable Lengths
Fiber (FDDI) Connections
The FDDI standard sets the maximum distances between stations to the fiber lengths shown in Table 2-5. The maximum circumference of the FDDI network is only half the specified distance because of signal wrapping or loopback during fault correction. The standard allows a maximum of 500 stations. Both single-mode and multimode transceiver types provide 11 dB of optical power.
Table 2-5 : FDDI Maximum Transmission Distances
MultiChannel E1 and T1 Connections
Following are the MIP E1 specifications:
Following are the MIP T1 specifications:
Serial Connections
As with all signaling systems, serial signals can travel a limited distance at any given bit rate; generally, the slower the baud rate, the greater the distance. Table 2-6 shows the standard relationship between baud rate and distance for EIA/TIA-232 signals.
Table 2-6 : IEEE Standard EIA/TIA-232C Transmission Speed versus Distance
Balanced drivers allow EIA/TIA-449 signals to travel greater distances than EIA/TIA-232. Table 2-7 shows the standard relationship between bit rate and distance for EIA/TIA-449 signals.
Table 2-7 : IEEE Standard EIA/TIA-449 Transmission Speed versus Distance
The recommended distance limits for EIA/TIA-449 shown in Table 2-7 are also valid for V.35, X.21, and EIA-530. However, you can get good results at distances and rates far greater than these. In common practice, EIA/TIA-449 and EIA-530 support 2-Mbps rates, and V.35 supports 4-Mbps rates without any problems; however, do so at your own risk.
SONET Connections The SONET specification for fiber-optic transmission defines two types of fiber: single mode and multimode. Modes can be thought of as bundles of light rays entering the fiber at a particular angle. Single-mode fiber allows only one mode of light to propagate through the fiber, while multimode fiber allows multiple modes of light to propagate through the fiber. Because multiple modes of light propagating through the fiber travel different distances depending on the entry angles, causing them to arrive at the destination at different times (a phenomenon called modal dispersion), singlemode fiber is capable of higher bandwidth and greater cable run distances than multimode fiber. The maximum distances for single-mode and multimode transmissions, as defined by SONET, are in Table 2-8. If the distance between two connected stations is greater than these maximum distances, significant signal loss can result, making transmission unreliable.
Table 2-8 : SONET Maximum Fiber-Optic Transmission Distances
Power Budget
To design an efficient optical data link, evaluate the power budget. The power budget is the amount of light available to overcome attenuation in the optical link and to exceed the minimum power that the receiver requires to operate within its specifications. Proper operation of an optical data link depends on modulated light reaching the receiver with enough power to be correctly demodulated.
Attenuation, caused by the passive media components (cables, cable splices, and connectors), is common to both multimode and single-mode transmission.
The following variables reduce the power of the signal (light) transmitted to the receiver in multimode transmission:
Attenuation is significantly lower for optical fiber than for other media. For multimode transmission, chromatic and modal dispersion reduce the available power of the system by the combined dispersion penalty (in decibels [dB]). The power lost over the data link is the sum of the component, dispersion, and modal losses. Table 2-9 lists the factors of attenuation and dispersion limit for typical fiber-optic cable.
Table 2-9 : Typical Fiber-Optic Link Attenuation and Dispersion Limits
Approximating the AIP Power Margin
The LED used for a multimode transmission light source creates multiple propagation paths of light, each with a different path length and time requirement to cross the optical fiber, causing signal dispersion (smear). Higher order mode loss (HOL) results from light from the LED entering the fiber and being radiated into the fiber cladding. A worst-case estimate of power margin (PM) for multimode transmissions assumes minimum transmitter power (PT), maximum link loss (LL), and minimum receiver sensitivity (PR). The worst-case analysis provides a margin of error, although not all of the parts of an actual system will operate at the worst-case levels.
The power budget (PB) is the maximum possible amount of power transmitted. The following equation lists the calculation of the power budget:
The power margin calculation is derived from the power budget and subtracts the link loss, as follows:
If the power margin is positive, as a rule, the link will work.
Table 2-10 lists the factors that contribute to link loss and the estimate of the link loss value attributable to those factors.
Table 2-10 : Estimating Link Loss
After calculating the power budget minus the data link loss, the result should be greater than zero. Results less than zero may have insufficient power to operate the receiver.
For SONET versions of the AIP module, the signal must meet the worst case parameters listed in Table 2-11.
Table 2-11 : AIP SONET Signal Requirements
Multimode Power Budget Example with Sufficient Power for Transmission
The following is an example calculation for a multimode power budget based on the following variables:
Estimate the power budget as follows:
The value of 2.5 dB indicates that this link would have sufficient power for transmission.
Multimode Power Budget Example of Dispersion Limit
Following is an example with the same parameters as the previous example, but with a multimode link distance of 4 km:
The value of 1.5 dB indicates that this link would have sufficient power for transmission; however, due to the dispersion limit on the link (4 km x 155.52 MHz > 500 MHzkm), this link would not work with multimode fiber. In this case, single-mode fiber would be the better choice.
Single-Mode Transmission
The singlemode signal source is an injection laser diode. Single-mode transmission is useful for longer distances because there is a single transmission path within the fiber and smear does not occur. In addition, chromatic dispersion is also reduced because laser light is essentially monochromatic.
The maximum overload specification on the single-mode receiver is --14 dBm. The single-mode receiver can be overloaded when using short lengths of fiber because the transmitter can transmit up to --8 dB. The receiver could be overloaded at --14 dB, but no damage will result. To prevent overloading the receiver connecting short fiber links, insert a 5 to 10 dB attenuator on the link between any singlemode SONET transmitter and the receiver.
SONET Single-Mode Power Budget Example
The following example of a single-mode power budget is of a two buildings, 11 kilometers apart, connected through a patch panel in an intervening building with a total of 12 connectors.
Estimate the power budget as follows:
The value of 2.5 dB indicates that this link would have sufficient power for transmission and is not in excess of the maximum receiver input power.
Using Statistics to Estimate the Power Budget
Statistical models more accurately determine the power budget than the worst-case method. Determining the link loss with statistical methods requires accurate knowledge of variations in the data link components. Statistical power budget analysis is beyond the scope of this document. For further information, refer to UNI Forum specifications, ITU-T standards, and your equipment specifications.
For Further Reference
The following publications contain information on determining attenuation and power budget:
HSSI Connections
The HSSI standard (EIA/TIA-612/613) specifies a maximum cable length of 50 feet (15 meters) for 52 Mbps HSSI connections. The typical (nominal) cable length between the HIP and the DSU is 6 feet (2 meters). The HSSI interface cable comprises 25 twisted pairs and a 50-pin plug at each end. Both DTE and DCE ports on the HIP and the DSU are 50-pin receptacles. The HSSI interface cable is similar to a SCSI-II-type (small computer systems interface) cable; however, the HSSI cable specification is more stringent than that for a SCSI-II.
Token Ring Connections
Currently there is no maximum transmission distance defined for IEEE 802.5 (Token Ring) networks. Shielded twisted-pair cabling is most commonly used for rates of 16 Mbps, and either shielded or unshielded twisted-pair cabling is used for rates of 1 and 4 Mbps. When planning your connections, remember that twisted-pair cabling is more susceptible to interference than other types of cabling, so plan the total network length and repeater spacing accordingly.
The rack-mounting hardware included with the router is suitable for most 19-inch equipment racks and Telco-type racks. Ideally, you should be able to access both the interface processor and non-interface processor ends of the router without having to remove it from the rack.
The router can be mounted in the rear of a rack. Before using a particular rack, check for obstructions (such as a power strip) that could impair rack-mount installation. If a power strip does impair a rear rack-mount installation, remove the power strip before installing the router in the rack, then replace it after the chassis is installed. As an alternative, the router can be mounted on an equipment shelf provided that the rack dimensions allow the router to be secured to the shelf and the overall configuration permits safe installation and access; however, we recommend rack-mount installation for the Cisco 7513. Figure 2-1 shows the chassis footprint and outer dimensions.
To use the rack-mounting hardware provided with the router, consider the following guidelines:
Figure 2-1 : Chassis Footprint and Outer Dimensions
When planning your rack installation, consider the following guidelines:
In addition to the preceding guidelines, review the precautions for avoiding overtemperature conditions in the section "Equipment-Rack Ventilation" in this chapter.
The router can operate as a standalone system placed on a table or as a rack-mounted system in a data processing or lab environment. The blower operates at 55 percent of capacity when it is possible to do so and maintain an acceptable operating temperature inside the chassis. If the temperature exceeds 23°C, the blower speed increases linearly until it reaches 100 percent. Although the blower supports quieter operation under normal conditions (approximately 62 dBa), the noise level when the blower is operating at 100-percent capacity is approximately 70 dBa. Therefore, the router is best suited for unattended or computer room use.
The router requires a dry, clean, well-ventilated, and air-conditioned environment. The internal blower pulls ambient air through the chassis to cool the internal components. To allow sufficient airflow, maintain a minimum of two inches of clearance at both the inlet and exhaust openings on the chassis. If the airflow is blocked or restricted, or if the inlet air is too warm, an overtemperature condition can occur. Under extreme conditions, the environmental monitor will shut down the power to protect the system components.
To help maintain normal operation and avoid unnecessary maintenance, plan your site configuration and prepare your site before installation. After installation, make sure that the site maintains an ambient temperature of 32 through 104°F (0 through 40°C), and keep the area around the chassis as free from dust as is practical. For a description of the environmental monitor and status levels, refer to "Environmental Monitoring and Reporting Functions" in the chapter "Product Overview."
If the temperature of the room air drawn into the chassis is higher than desirable, the air temperature inside the chassis may also be too high. This condition can occur when the wiring closet or rack in which the chassis is mounted is not ventilated properly, when the exhaust of one device is placed so it enters the air inlet vent of the chassis, or when the chassis is the top unit in an unventilated rack. Any of these conditions can inhibit air flow and create an overtemperature condition.
Because the inlet air flows into one part of the chassis and out another, other devices can be rack-mounted with as little as one inch of clearance above and below the chassis. However, when mounting a router in a rack with other equipment, or when placing it on a table with other equipment located close by, ensure that the exhaust from other equipment does not blow into the inlet of the chassis. The inlet air is drawn in and exhausted as shown in Figure 1-5.
Table 2-12 lists the operating and nonoperating environmental site requirements. To maintain normal operation and ensure high system availability, maintain an ambient temperature and clean power at your site. The following ranges are those within which the router will continue to operate; however, a measurement that is approaching the minimum or maximum of a range indicates a potential problem. You can maintain normal operation by anticipating and correcting environmental anomalies before they approach the maximum operating range.
Table 2-12 : Specifications for Operating and Nonoperating Environments
Preventive Site Configuration: Maintaining Normal Operation
Planning a proper location for the router and the layout of your equipment rack or wiring closet are essential for successful system operation. Equipment placed too close together or inadequately ventilated can cause system overtemperature conditions. In addition, chassis panels made inaccessible by poor equipment placement can make system maintenance difficult. Following are precautions that can help avoid problems during installation and ongoing operation.
Follow these general precautions when planning your equipment locations and connections:
If you plan to install the router in an equipment rack, you can avoid overtemperature conditions by following the guidelines in the section "Equipment Racks" in this chapter in addition to the following precautions:
For a functional description of the environmental monitor and the status levels, refer to the section "Environmental Monitoring and Reporting Functions" in the chapter "Product Overview."
Follow these precautions and recommendations when planning power connections to the router:
The AC-input-powered chassis operating at 120VAC requires a minimum of 20-amp service, with a 20-amp receptacle at the power source. The power cable supplied with the chassis uses a 20-amp plug. Figure 2-2 shows cable features required to connect the 20-amp plug to your AC source.
Figure 2-2 : 20-Amp AC Power Cable Connector and Plug, and 20-Amp Receptacle
The DC powered chassis requires a minimum 35A dedicated service (at --48VDC). We recommend that you use an 8 AWG, highly flexible, stranded cable for the DC power connections. Figure 2-3 shows the conductor preparation for the DC-input cable connections.
Figure 2-3 : DC Power Cable Connection to Terminal Block
When preparing your site for network connections to the router, you must consider a number of factors related to each type of interface, such as the type of cabling required for each type (fiber, thick or thin coaxial, or unshielded twisted-pair cabling), distance limitations for each signal type, the specific cables you need to connect each interface, and any additional interface equipment you need, such as transceivers, hubs, switches, modems, channel service units (CSUs), or data service units (DSUs). Before installing the router, have all additional external equipment and cables on hand. If you intend to build your own cables, refer to the cable pinouts in the appendix "Cabling Specifications." For ordering information, contact a customer service representative.
Additional and Optional Connection Equipment
You may need some of the following data communications equipment to complete your installation:
All AIP ATM interfaces are full-duplex. You must use the appropriate ATM interface cable to connect the AIP with an external ATM network.
The AIP provides an interface to ATM switching fabrics for transmitting and receiving data at rates of up to 155 Mbps bidirectionally; the actual rate is determined by the physical layer interface module (PLIM). The AIP can support PLIMs that connect to the following physical layers:
For wide-area networking, ATM is currently being standardized for use in Broadband Integrated Services Digital Networks (BISDNs) by the International Telecommunications Union Telecommunication Standardization Sector (ITU-T) (formerly the Consultative Committee for International Telegraph and Telephone (CCITT)) and the American National Standards Institute (ANSI). BISDN supports rates from E3 (34 Mbps) to multiple gigabits per second (Gbps).
The DS3 interface performs physical-layer translation from the AIP to a DS3 line interface in accordance with ATM Forum UNI Specification Version 3.1, ACCUNET T45 service specifications, and ANSI T1.107. The ATM User-to-Network Interface (UNI) specification defines the required MIB functionality for ATM interfaces. Refer to the ATM UNI specification for additional details.
ATM UNI information is arranged into a MIB fashion. MIB attributes are readable and writable across the Interim Local Management Interface (ILMI) using a Simple Network Management Protocol (SNMP). The ILMI uses SNMP, without UDP, and interface processor addressing along with the ATM MIB. The AIP supports RFC 1213 interface MIBs as specified in the ATM MIB V2 specification.
The ATM interface cable is used to connect your router to an ATM network or to connect two routers back to back. Cables can be obtained from the following cable vendors: AT&T, Siemens, Red-Hawk, Anixter, and AMP.
For 4B/5B traffic over multimode fiber, use the multimode MIC interface cable to connect the AIP with the external ATM switch. (See Figure 2-4.)
Figure 2-4 : Multimode Network Interface Connector (MIC Type)
For SONET/SDH multimode connections, use one multimode duplex SC connector (see Figure 2-5) or two single SC connectors. (See Figure 2-6.)
Figure 2-5 : Duplex SC Connector
Figure 2-6 : Simplex SC Connector
For SONET/SDH single-mode connections, use the single-mode (ST2) connector (bayonet-style twist-lock). (See Figure 2-7.)
For E3 and DS3 connections, use the 75 ohm, RG-59, coaxial cable, CAB-ATM-DS3/E3, which has bayonet-style, twist-lock (BNC) connectors and ferrite beads. (See Figure 2-8.) The E3 and DS3 PLIMs both require cable CAB-ATM-DS3/E3.
Figure 2-8 : CAB-ATM-DS3/E3 Cable---RG-59 Coaxial Cable with BNC Connectors
For multimode connections, connect the multimode interface cable to the media interface cable (MIC) connector on the 4B/5B PLIM. (See Figure 2-9.)
Figure 2-9 : MIC Connector on a 4B/5B PLIM
For multimode SONET connections, connect the multimode cable to the SC connector on the PLIM. (See Figure 2-10.)
Figure 2-10 : SONET Multimode SC Duplex PLIM
The SONET multimode SC-duplex connector is shipped with a dust plug. (See Figure 2-11.) Remove the plug by pulling on the plug as you squeeze the sides.
Figure 2-11 : SONET ATM Multimode Fiber Optic Transceiver and Dust Plug
For single-mode SONET connections, connect the single-mode cable to the ST connector on the SONET PLIM. (See Figure 2-12.)
Figure 2-12 : SONET Single-Mode PLIM
For E3 and DS3 connections, connect the coaxial cable to the BNC connector on the E3 or DS3 PLIM. (See Figure 2-13.) The E3 and DS3 PLIMs require cable CAB-ATM-DS3/E3. Ensure that the transmit and receive portions of the cable are connected to the appropriate PLIM connector. The E3 PLIM connection requires an EMI filter clip (CLIP-E3-EMI) on the receive port (RCVR). Refer to the chapter "Installing the Router."
Figure 2-13 : E3 and DS3 PLIM---Representative of Both PLIMs
Channel Attachment Connection Equipment
The ESCON Channel Adapter (ECA) and bus and tag Parallel Channel Adapter (PCA) for the CIP are available as FRUs; however, they are field replaceable by Cisco-certified field service personnel only. For more information on the ECA, PCA, CIP, and respective cable requirements, refer to the configuration note Channel Attachment Interface Processor (CIP) Installation and Configuration (Document Number 78-1342-xx), which is available on UniverCD or in print. This configuration note also ships with the CIP spare parts and FRUs.
You will need an 802.3 MAU and an AUI, or an Ethernet transceiver and transceiver cable between each EIP port and the Ethernet network. The Ethernet connectors on the EIP are standard 15-pin AUI receptacles that require an AUI or transceiver interface cable with a DB-15 AUI plug. (See Figure 2-14.)
Figure 2-14 : Ethernet Interface Cable Connectors
The term Ethernet is commonly used for all carrier sense multiple access/collision detection (CSMA/CD) local-area networks (LANs) that generally conform to Ethernet specifications, including IEEE 802.3. Ethernet Version 2 and IEEE 802.3 were based on, and developed shortly after, Ethernet Version 1. The slight differences between Ethernet and IEEE 802.3 are implemented in hardware, and both are supported automatically by the EIP without any hardware or software configuration changes. Together, Ethernet and IEEE 802.3 are the most widely used local-area network protocol. They are well suited to applications where a local communication medium must carry sporadic, occasionally heavy traffic at high peak data rates.
Stations on a CSMA/CD LAN can access the network at any time. Before sending data, the station listens to the network to see of it is already in use. If it is, the station waits until the network is not in use, then transmits. A collision occurs when two stations listen for network traffic, hear none, and transmit simultaneously. When this happens, both transmissions are damaged, and the stations must retransmit them. The stations detect the collision and use backoff algorithms to determine when they should retransmit.
Both Ethernet and IEEE 802.3 are broadcast networks, which means that all stations see all transmissions. Each station must examine received frames to determine whether it is the intended destination and, if it is, pass the frame to a higher protocol layer for processing.
IEEE 802.3 specifies several different physical layers, and Ethernet defines only one. Each IEEE 802.3 physical layer protocol has a name that summarizes it characteristics in the format speed/signalling method/segment length where speed is the LAN speed in Mbps, signaling method is the signaling method used (either baseband or broadband), and segment length is the maximum length between stations in hundreds of meters. For example, 10BASE-5 specifies a 10Mbps Baseband LAN with network segments spaced at 500 meters.
Table 2-13 summarizes the characteristics of Ethernet Version 2 and IEEE 802.3.
Table 2-13 : Ethernet Version 2 and IEEE 802.3 Physical Characteristics
Ethernet is most similar to IEEE 802.3 10BASE-5. Both of these protocols specify a bus topology network with a connecting cable between the end stations and the actual network medium. Both protocols require a device that acts as an interface between the end stations (the EIP) and the actual network medium (cable). The Ethernet specifications call this device a transceiver and it is connected to the station with a transceiver cable. The IEEE 802.3 specification refers to the same type of device as a media attachment unit (MAU) and to the cable as an attachment unit interface (AUI). Both transceiver cables and AUIs can connect to the EIP ports directly.
Transceivers are available from a variety of sources for thick-wire (10BASE-5), thin-wire (10BASE-2), or unshielded twisted-pair cabling (10BASE-T at 10 Mbps); Figure 2-15 shows examples of transceivers and connection equipment. You can connect either Ethernet Version 1 or Version 2/IEEE 802.3 interfaces; the EIP automatically supports both types.
Figure 2-15 : Ethernet Transceivers for the EIP
Typically, Ethernet connectors have either slide-type or jackscrew-type locks. (See Figure 2-16.) The most common are those that use a slide-type lock, which is the type used on the EIP ports. The connector on the left in Figure 2-16 shows a slide-type lock. When the cable is connected to the 15-pin port, a metal bracket snaps up over two posts on the cable connector to secure it in the port and provide strain relief. The jackscrew-type lock, shown on the right in Figure 2-16, uses two thumbscrews or jackscrews, which are usually attached to the cable connector, instead of the posts and sliding bracket. When the cable is connected to the 15-pin port, you secure it by screwing the thumbscrews into the jackscrews adjacent to the connector.
Figure 2-16 : Ethernet Connector Locks, Slide-Type and Jackscrew-Type
The slide-type locks are standard on the EIP ports; however, conversion kits are included with each EIP to replace the slide-type locks with jackscrews. For specific replacement instructions, refer to the installation document that accompanies the jackscrew kit.
Fast Ethernet Connection Equipment
The two connectors on the FEIP port adapter are a single MII, 40-pin, D-shell type, and a single RJ-45. You can use either one or the other. Only one connector can be used at one time. The FEIP can have up to two port adapters installed. Each connection supports IEEE 802.3u interfaces compliant with the 100BASE-X and 100BASE-T standards. The RJ-45 connection does not require an external transceiver; however, the MII connection does, depending on the type of connection you use.
The RJ-45 modular connector (see Figure 2-17) has strain relief functionality incorporated into the design of its standard plastic connector. Figure 2-17 and Figure 2-18 show the RJ-45 and MII connectors.
Figure 2-17 : RJ-45 Connections---Connector and Plug
Depending on the type of media you use between the MII connection on the port adapter and your switch or hub, the network side of your 100BASE-T transceiver should be appropriately equipped: with ST-type connectors (for optical fiber), BNC connectors (for 10BASE-2 coaxial cable), and so forth. Figure 2-18 shows the pin orientation of the female MII connector on the port adapter.
Figure 2-18 : MII Connection---Female
The MII receptacle uses 2-56 screw-type locks, called jackscrews (shown in Figure 2-18), to secure the cable or transceiver to the MII port. MII cables and transceivers have knurled thumbscrews (screws you can tighten with your fingers) that you fasten to the jackscrews on the FEIP MII connector. Use the jackscrews to provide strain relief for your MII cable.
Token Ring Connection Equipment
The term Token Ring refers to both IBM's Token Ring Network, which IBM developed in the 1970s, and to IEEE 802.5 networks. The IEEE 802.5 specification was modeled after, and still closely shadows, IBM's network. The two types are compatible, although the specifications differ slightly.
You will need an 802.5 MAU or a multistation access unit (MSAU) to provide the interface between the TRIP Token Ring interfaces and the external ring, and a Token Ring lobe cable between each TRIP port and the MAU or MSAU. Lobe cables connect each Token Ring station (TRIP port) to the MAU or MSAU, and patch cables can connect adjacent MSAUs to form one large ring.
Before you enable the Token Ring interfaces, ensure that each is set for the correct speed, or it can bring down the ring. TRIP ports operate at either 4 or 16 Mbps. The default speed for all TRIP ports is 4 Mbps, which you can change to 16 Mbps on any port with the configuration command ring-speed n, where n is the speed (4 or 16) in Mbps. The speed of each Token Ring port must match the speed of the ring to which it is connected.
Token Ring Cables and Connectors
The Token Ring ports on the TRIP are DB-9 (PC type) receptacles that require Type 1 or Type 3 lobe cables. Type 1 lobe cables use shielded twisted pair cable and terminate at the network end with a large MAU plug. (See Figure 2-19.)
Figure 2-19 : TRIP Token Ring Type 1 Lobe Cable Connectors, DB-9 and MAU Types
Type 3 lobe cables use either shielded twisted pair (STP) or unshielded twisted pair (UTP) cable and terminate at the network end with an RJ-11 plug. (See Figure 2-20.) The TRIP end of both cable types is a DB-9 plug.
Figure 2-20 : TRIP Token Ring Type 3 Lobe Cable Connectors, DB-9 and RJ-11 Types
Token Ring Physical Connections
The IBM Token Ring specifies a star topology, with all end stations connected through a device called a multistation access unit (MSAU). IEEE 802.5 does not specify any topology, although most implementations are based on a star configuration with end stations attached to a device called a media access unit (MAU). Also, IBM Token Ring specifies twisted pair cabling, whereas IEEE 802.5 does not specify media type. Most Token Ring networks use shielded twisted pair cabling; however, some networks that operate at 4 Mbps use unshielded twisted pair cable.
Table 2-14 shows a comparison of the two types.
Table 2-14 : IBM Token Ring and IEEE 802.5 Comparison
In the typical Token Ring network shown in Figure 2-21, lobe cables connect each Token Ring station (TRIP port) to the MSAU (or MAU), and patch cables connect adjacent MSAUs (or MAUs) to form one large ring.
Figure 2-21 : Token Ring Network Physical Connections
Token Ring and IEEE 802.5 are token-passing networks, which move a small frame, called a token, around the network. Possession of the token grants the right to transmit; a station with information to transmit must wait until it detects a free token passing by.
When all stations on the ring are idle, the token packet is labeled as a free token. If the station receiving the token has no information to send, it simply passes the free token to the next station. A station that does have information to transmit seizes the token, alters a bit of the token frame (which changes the free token to a busy token), appends the information it wishes to transmit, and then sends this information to the next station on the ring. The busy token, with the information frame, circulates the ring until it reaches the intended destination station, which copies the information for further processing and passes the busy token and information frame back out to the ring.
The information frame continues to circle the ring until it reaches the original sending station, which checks the returned frame to ensure that the destination station received the information. When the original sending station determines that the receiving station accepted the information, it purges the token and information frame, and transmits a new free token out to the ring.
While the information frame is circling the ring, there is no token on the network (unless early token release is enabled, which is described later in this section), so other stations wishing to transmit must wait. Therefore, collisions cannot occur in Token Ring networks.
A priority scheme allows the user to designate any station as high priority, which allows the station to use the ring more frequently than lower-priority stations. Stations cannot seize or reserve a passing token with a higher priority than its own designated priority, which allows highest-priority stations to seize the token as soon as possible. The token frame contains a priority field, which is set by the station that generates the token, and a reservation field, which can be set by a higher-priority station as it receives and passes the token.
When a token is circulating, only stations with a priority equal to or higher than the priority value in the token fields can seize that token or reserve the next token. Once the token is seized and changed to a busy token with an information frame, a station with a higher priority than the transmitting station can reserve the next token (for the next pass around the network) by setting the reservation field. When the original sending station receives a token with the reservation field set for a higher-priority station, it issues the new free token with the priority field set to that of the reserving station. Only the reserving station or another station with an equal or higher priority can seize the token. After the higher-priority station seizes the token and completes it transmission, it must first determine that all other higher-priority stations are finished transmitting and then reinstate the previous, lower priority. When the station detects a free token with the higher priority, it assumes that there is no more higher-priority traffic waiting and downgrades the priority of the token before passing it back onto the ring.
Early token release allows a station to release a new token onto the ring immediately after transmitting, instead of waiting for the first frame to return. This feature can help increase the total bandwidth on the ring, but decreases ring reliability. The TRIP supports early token release, but by default it is not enabled on any TRIP ports.
Unlike CSMA/CD networks such as Ethernet, token-passing networks are deterministic. Each station can hold the token for a maximum period of time, so it is possible to calculate the maximum time that will pass before any end station will be able to transmit. This and the fault management mechanisms discussed in the following section make Token Ring networks robust and predictable.
Token Ring networks employ several mechanisms for detecting and compensating for network faults. For example, one station in the Token Ring network is designated as the active monitor. This station, which potentially can be any station on the network, acts as a centralized source of timing information for other ring stations and performs a variety of ring maintenance functions. These functions include detecting and correcting a lost or persistently busy (continuously circulating) token on the ring.
To detect a lost token, the active monitor uses a timeout greater than the time required for the longest frame to traverse the ring completely. If the active monitor does not see a token during this time, it assumes that the token is lost, purges the ring of any residual data, and issues a new token.
When a sending device fails, its frame may continuously circle the ring, preventing other stations from transmitting their own frames and essentially locking up the network. To detect a circulating busy token, the active monitor sets a monitor bit to 1 on any passing busy token. If it sees a busy token with a bit already set, it knows that the transmitting station failed to purge its packet. The monitor changes the busy token to a free token, and sends it back out to the ring.
Other stations on the ring have the role of passive monitor; their primary job is to detect failure of the active monitor and assume that role if necessary. A contention-resolution algorithm determines which station takes over if the active monitor fails.
A Token Ring algorithm called beaconing detects and tries to repair certain network faults. Whenever a station detects a serious problem with the network (such as a cable break), it sends a beacon frame. The beacon frame defines a failure domain, which includes the station reporting the failure, its nearest active upstream neighbor, and everything in between. Beaconing initiates a process called autoreconfiguration, where nodes within the failure domain automatically perform diagnostics and attempt to reconfigure the network around the failed areas. Physically, the MSAU or MAU can accomplish this through electrical reconfiguration.
All information in a Token Ring network is seen by active MSAUs or MAUs. Some of these devices can be programmed to check for problems and automatically remove problem stations from the ring, and some contain bypass relays so that you can selectively remove stations from the ring without affecting traffic on the network.
All TRIP ports support both 4 and 16 Mbps operation and early token release. The default for all ports is for 4 Mbps operation and early token release disabled. Both states are enabled with configuration commands in the configuration mode. To enable 16 Mbps, specify the slot/port address and use the configuration command ring-speed 16; to return to 4 Mbps operation, use the command ring-speed 4. To enable and disable early token release, specify the slot/port address and use the configuration command [no] early token release. For examples of these commands, refer to "Token Ring Connections" in the chapter "Installing the Router." For complete descriptions and examples of software commands, refer to the related software configuration documentation.
Fiber-optic transceivers on the FIP provide a direct interface between the router and the FDDI ring. The FIP supports both single-mode and multimode transceivers and is available with any combination of the two types. Both transceiver types provide a Class A dual-attach interface that can be connected to a Class A or a Class B station. Class A is a dual-attach station (DAS) with primary and secondary rings; Class B is a single-attach station (SAS) with only a primary ring. A detailed description of Class A and B and of DASs and SASs follows the descriptions of FDDI connection equipment.
FDDI networks use two types of fiber-optic cable: single-mode (also called monomode) and multimode. Mode refers to the angle at which light rays (signals) are reflected and propagated through the optical fiber core, which acts as a waveguide for the light signals. Multimode fiber has a relatively thick core (62.5/125-micron) that reflects light rays at many angles. Single-mode fiber has a narrow core (8.7/125 to 10/125-micron) that allows the light to enter only at a single angle.
Although multimode fiber allows more light signals to enter at a greater variety of angles (modes), the different angles create multiple propagation paths that cause the signals to spread out in time and limits the rate at which data can be accurately received. This distortion does not occur on the single path of the single-mode signal; therefore, single-mode fiber is capable of higher bandwidth and greater cable run distances than multimode fiber. In addition, multimode transmitters usually use LEDs as a light source, and single-mode transmitters use a laser diode, which is capable of sustaining faster data rates. Both types use a photodiode detector at the receiver to translate the light signal into electrical signals.
FDDI Transceivers and Cable Connectors
The FIP single-mode interface uses simplex, FC-type connectors for the transmit and receive ports. (See Figure 2-22.) The connector accepts standard 8.7/125 to 10/125-micron single-mode fiber-optic cable. The single-mode interface supports connections at distances up to 6 miles (10 kilometers).
Figure 2-22 : Single-Mode FDDI Network Interface Connectors, FC Type
The multimode transceiver supports distances of up to 1.2 miles (1.9 kilometers). The multimode connector is an FDDI-standard physical sublayer (PHY) connector that encodes and decodes the data into a format acceptable for fiber transmission. The multimode connector accepts standard 62.5/125-micron multimode fiber-optic cable using the media interface cable (MIC) and, with proper cable terminators, can accept 50/125 micron fiber-optic cable. Multimode uses the integrated MIC shown in Figure 2-23 at both the FIP and network ends.
Figure 2-23 : Multimode FDDI Network Interface Connector, MIC Type
The multimode/multimode FIP (CX-FIP-MM) and the single-mode/single-mode FIP (CX-FIP-SS) provide a control port for an optical bypass switch, which allows the light signal to pass directly through the bypass switch and completely bypass the FIP transceivers when the interface has failed or is shut down. Most optical bypass switches provide the necessary interface cables for connection to the connectors on the FIP; however, not all manufacturers use the same type of DIN connector for the control port. Some manufacturers use a DIN, and some use a smaller version, called a mini-DIN. The optical bypass control port on the FIP requires a mini-DIN connector. A DIN-to-mini-DIN adapter cable (CAB-FMDD) is included with the FIP to ensure that you can connect to either type.
The FIP supports both Class A and Class B station connections and provides an interface for both single-mode and multimode fiber-optic cable. The two physical ports (PHY A and PHY B) are available with either single-mode (FC) or multimode (MIC) port connectors, or with a combination of one of each for matching multimode and single-mode fiber in the same FDDI network.
Fiber Distributed Data Interface (FDDI), which specifies a 100-Mbps, token-passing dual-ring network using fiber-optic transmission media, is defined by the ANSI X3.1 standard and by ISO 9314, the international version of the ANSI standard. An FDDI network comprises two token-passing fiber-optic rings: a primary ring and a secondary ring. An FDDI ring consists of two or more point-to-point connections between adjacent stations.
An FDDI ring consists of two or more point-to-point connections between adjacent stations. On most networks, the primary ring is used for data communication, and the secondary ring is used as a backup. Class B, or single-attach stations (SAS), attach to one ring and are typically attached through a concentrator; Class A, or dual-attach stations (DAS), attach to both rings. Figure 2-24 shows a typical FDDI configuration with both DASs and SASs.
Figure 2-24 : Typical FDDI Configuration with DAS, Concentrator, and SAS
SASs (Class B) typically attach to the primary ring through a concentrator, which provides connections for multiple SASs. The concentrator ensures that a failure or power down of any SAS does not interrupt the ring. SASs use one transmit port and one receive port to attach to the single ring. DASs (Class A) have two physical ports, designated PHY A and PHY B, each of which connects the station to both the primary and secondary rings. Each port is a receiver for one ring and a transmitter for the other. For example, PHY A receives traffic from the primary ring, and PHY B transmits to the primary ring.
The dual rings in an FDDI network provide fault tolerance. If a station on a dual ring shuts down or fails, such as Station 3 in Figure 2-25, the ring automatically wraps (doubles back on itself) to form a single contiguous ring. This removes the failed station from the ring, but allows the other stations to continue operation. In Figure 2-25, the ring wraps to eliminate Station 3 and forms a smaller ring that includes only Stations 1, 2, and 4.
Figure 2-25 : DAS Station Failure and Ring Recovery Example
A second failure could cause the ring to wrap in both directions from the point of failure, which would segment the ring into two separate rings that could not communicate with each other. For example, if Station 1 in Figure 2-25 fails after Station 3 fails, Stations 2 and 4 will each be isolated because no path for communication exists between them. Subsequent failures cause additional segmentation.
Optical bypass switches avoid segmentation by eliminating failed stations from the ring. During normal operation, an optical bypass switch allows the light signal to pass directly through itself uninterrupted. When a station with a bypass switch fails, the bypass switch reroutes the signal back onto the ring before it reaches the failed station, so the ring does not have to wrap back on itself.
Figure 2-26 shows an optical bypass switch installed at Station 1. In the normal configuration shown on the left, Station 1 is functioning normally, so the optical bypass switch appears transparent. The switch essentially allows the signals to pass through it without interruption. However, if Station 1 fails, the optical bypass switch enables the bypassed configuration shown on the right in Figure 2-26.
Figure 2-26 : Optical Bypass Operation on a DAS
The bypass switch reroutes the light signal by intercepting it before it reaches the failed Station 1 and sends it back out to the ring. This allows the signal to maintain its existing path and direction without wrapping back on itself. However, stations that are operating normally repeat the signal when sending it back out to the ring. Optical bypass switches do not repeat or drive the signal (they just allow the signal to pass through them), so significant signal loss can occur when the downstream neighbor (the next station on the ring) is far away.
Another technique for fault tolerance is dual homing, whereby critical devices are attached to two concentrators. Only the designated primary concentrator is active unless it (or its link) fails. If the primary does fail, the backup (passive) concentrator is activated automatically and sustains the ring.
MultiChannel Connection Equipment
The MIP T1 interface cable has two 15-pin DB connectors at each end to connect the MIP with the external CSU. Figure 2-27 shows the MIP interface cable and connectors.
Figure 2-27 : T1 Interface Cable
For E1, four serial cables are available for use with the MIP. All four have DB-15 connectors on the MIP end and either BNC, DB-15, Twinax, or RJ-48 connectors on the network end. Figure 2-28, Figure 2-29, Figure 2-30, and Figure 2-31 show the E1 interface cables.
Refer to the appendix "Cabling Specifications" for the T1 and E1 cable pinouts.
Figure 2-28 : E1 Interface Cable for 75-Ohm, Unbalanced Connections (with BNC Connectors)
Figure 2-29 : E1 Interface Cable for 120-Ohm, Balanced Connections (with DB-15 Connectors)
Figure 2-30 : E1 Interface Cable for 120-Ohm, Balanced Connections (with Twinax Connectors)
Figure 2-31 : E1 Interface Cable for 120-Ohm, Balanced Connections (with RJ-48 Connector)
Following are the available MIP cables:
The FSIP supports synchronous serial connections at T1 and E1 speeds; the actual speed depends on the type of electrical interface used, the distances the signals must travel, and the configuration of other ports on the same FSIP module. In general, you should use EIA/TIA-232 for speeds of 64 kbps and below, and use X.21, EIA/TIA-449, V.35, or EIA-530 for higher speeds. (See the section "Configuring the FSIP" in the chapter "Maintaining the Router.") The universal FSIP ports for all interface types are 60-pin, D-shell receptacles. Each port requires a serial port adapter cable to connect to the external network or connection device.
On data communications ports, the universal serial port adapter cable determines the electrical interface type and mode of the port. All universal serial cables use a 60-pin D-shell plug at the router (FSIP) end. The network end of each cable provides the standard connector used with each respective interface type. (See Figure 2-32.) Cables for all data communications interfaces except EIA-530 are available in DTE mode with a plug at the network end, or in DCE mode with a receptacle at the network end. The mode, DCE or DTE, is labeled on the connectors at both ends of the cables.
Figure 2-32 : Serial Port Adapter Cables
Metric (M3) thumbscrews are included with each port adapter cable to allow connection to devices that use metric hardware. Following are the available interface cable options for the mode and network-end connectors for each:
Figure 2-33, Figure 2-34, and Figure 2-35 show the unbalanced and balanced cables used for connection between the E1-G.703/G.704 port adapter and your network. The port-adapter end of each cable has a DB-15 connector.
Following are the E1-GG.703/G.704 interface cables to connect the FSIP and CSU:
All data communications interfaces support both nonreturn to zero (NRZ) and nonreturn to zero inverted (NRZI) formats. Both formats use two different voltage levels for transmission. NRZ signals maintain constant voltage levels with no signal transitions (no return to a zero voltage level) during a bit interval and are decoded using absolute values (0 and 1). NRZI uses the same constant signal levels but interprets the presence of data at the beginning of a bit interval as a signal transition and the absence of data as no transition. NRZI uses differential encoding to decode signals, rather than determining absolute values. NRZ, the factory default on all interface types, is most common. All interface types also support NRZI format, which is commonly used with EIA/TIA-232 connections in IBM environments. (See the section "Configuring NRZI Format" in the chapter "Maintaining the Router" for configuration instructions.)
All data communications interfaces use a 16-bit cyclic redundancy check (CRC) by default but also support a 32-bit CRC. CRC is an error-checking technique that uses a calculated numeric value to detect errors in transmitted data. The sender of a data frame divides the bits in the frame message by a predetermined number to calculate a remainder or frame check sequence (FCS). Before it sends the frame, the sender appends the FCS value to the message so that the frame contents are exactly divisible by the predetermined number. The receiver divides the frame contents by the same predetermined number that the sender used to calculate the FCS. If the result is not 0, the receiver assumes that a transmission error occurred and sends a request to the sender to resend the frame.
The designators 16 and 32 indicate the number of check digits per frame that are used to calculate the FCS. Sixteen-bit CRC, which transmits streams of 8-bit characters, generates a 16-bit FCS. Thirty-two bit CRC, which transmits streams of 16-bit characters, generates a 32-bit FCS. Because 32-bit CRC transmits longer streams at faster rates, it provides better ongoing error detection with less retransmits. Both the sender and the receiver must use the same setting.
Sixteen-bit CRC is the most widely used method throughout the United States and Europe, and it is used extensively with wide-area networks (WANs). IEEE-802 specifies 32-bit CRC, and some point-to-point transmission standards specify it as an option. It is often used on SMDS networks and LANs. (See the section "Configuring 32-Bit Cyclic Redundancy Check" in the chapter "Maintaining the Router" for configuration instructions.)
Data communications ports operate in either DCE or DTE mode; the mode depends on the source of the clock signal that the port uses, and the mode of the remote device to which the port is connected. In DCE mode, the port supplies its own clock signal.
You normally use DCE when connecting the router to a DTE device such as a PC, host, or another router. To set up a port as a DCE interface, you must use a DCE adapter cable and use the clockrate configuration command to set the internal clock speed.
In DTE mode, which is the most commonly used mode, the port uses a clock signal supplied by a remote or external device. You normally use DTE when connecting the router to a DCE device such as a modem or CSU/DSU. Most DTE interfaces require an external clock signal, which the remote DCE device provides. To set up a port as a DTE interface, you need only connect a DTE adapter cables. When the port recognizes the DTE cable, it automatically uses the clock signal from the remote DCE device.
Occasionally, systems with long cables may experience high error rates when operating at the higher transmission speeds. Slight variances in cable construction, temperature, and network configuration can cause the clock and data signals to shift out of phase. Inverting the clock can often correct this shift. If an FSIP port is reporting a high number of error packets, suspect a phase shift and invert the clock by the invert-transmit-clock command.
For brief descriptions of the clockrate and invert-transmit-clock commands, refer to the section "Configuring Timing (Clock) Signals" in the chapter "Maintaining the Router." For complete command descriptions and instructions, refer to the related software documentation.
All serial signals are subject to distance limits, beyond which a signal degrades significantly or is completely lost. For specific cabling distance limitations, refer to the section "Distance Limitations and Interface Specifications" in this chapter. The distance and rate limits in these descriptions are the IEEE-recommended maximum speeds and distances for signaling; however, you can usually get good results at speeds and distances far greater than these. For instance, the recommended maximum rate for V.35 is 2 Mbps, but 4 Mbps is commonly used without any problems. If you understand the electrical problems that might arise and can compensate for them, you should get good results with rates and distances greater than those shown here. However, do so at your own risk.
By far the most common interface standard in the U.S., EIA/TIA-232, supports unbalanced circuits at signal speeds up to 64 kbps. The router (FSIP) end of all EIA/TIA-232 adapter cables is a high-density 60-pin plug. The opposite (network) end of the adapter cable is a standard 25-pin D-shell connector (known as a DB-25) that is commonly used for EIA/TIA-232 connections. Figure 2-36 shows the connectors at the network end of the adapter cable. The system Console and Auxiliary ports on the RSP2 also use EIA/TIA-232 connections; however, the FSIP ports support synchronous connections, and the Console and Auxiliary ports support only asynchronous connections.
Figure 2-36 : EIA/TIA-232 Adapter Cable Connectors, Network End
For further information on the RSP2 ports, refer to the section "Console and Auxiliary Port Connection Equipment" in this chapter. For cable pinouts, refer to the appendix "Cabling Specifications."
EIA/TIA-449, which supports balanced (EIA/TIA-422) and unbalanced (EIA/TIA-423) transmissions, is a faster (up to 2 Mbps) version of EIA/TIA-232 that provides more functions and supports transmissions over greater distances. The EIA/TIA-449 standard was intended to replace EIA/TIA-232, but it was not widely adopted. Industry's resistance to convert to EIA/TIA-449 was due primarily to the large installed base of DB-25 hardware and to the larger size of the 37-pin EIA/TIA-449 connectors, which limited the number of connections possible (fewer than possible with the smaller, 25-pin EIA/TIA-232 connector). (See
The router (FSIP) end of all EIA/TIA-449 adapter cables is a high-density 60-pin plug. The opposite (network) end of the adapter cable provides a standard 37-pin D-shell connector commonly used for EIA/TIA-449 connections. Figure 2-37 shows the connectors at the network end of the adapter cable. EIA/TIA-449 cables are available as either DTE (DB-37 plug) or DCE (DB-37 receptacle). For cable pinouts, refer to the appendix "Cabling Specifications."
Figure 2-37 : EIA/TIA-449 Adapter Cable Connectors, Network End
The V.35 interface is most commonly used in the United States and throughout Europe and is recommended for speeds up to 48 kbps (although in practice it is used successfully at 4 Mbps). The router (FSIP) end of all V.35 adapter cables is a high-density 60-pin plug. The opposite (network) end of the adapter cable provides a standard 34-pin Winchester-type connector commonly used for V.35 connections.
Figure 2-38 shows the connectors at the network end of the V.35 adapter cable. V.35 cables are available with a standard V.35 plug for DTE mode (CAB-V35MT=) or a V.35 receptacle for DCE mode (CAB-V35FC=). For cable pinouts, refer to the appendix "Cabling Specifications."
Figure 2-38 : V.35 Adapter Cable Connectors, Network End
The X.21 interface uses a 15-pin connection for balanced circuits and is commonly used in the United Kingdom to connect public data networks. X.21 relocates some of the logic functions to the DTE and DCE interfaces and, as a result, requires fewer circuits and a smaller connector than EIA/TIA-232.
The router (FSIP) end of all X.21 adapter cables is a high-density 60-pin plug. The opposite (network) end of the adapter cable is a standard DB-15 connector. Figure 2-39 shows the connectors at the network end of the X.21 adapter cable. X.21 cables are available as either DTE (DB-15 plug) or DCE (DB-15 receptacle). For cable pinouts, refer to the appendix "Cabling Specifications."
Figure 2-39 : X.21 Adapter Cable Connectors, Network End
EIA-530, which supports balanced transmission, provides the increased functionality, speed, and distance of EIA/TIA-449 on the smaller, DB-25 connector used for EIA/TIA-232. The EIA-530 standard was created to support the more sophisticated circuitry of EIA/TIA-449 on the masses of existing EIA/TIA-232 (DB-25) hardware instead of the larger, 37-pin connectors used for EIA/TIA-449. Like EIA/TIA-449, EIA-530 refers to the electrical specifications of EIA/TIA-422 and EIA/TIA-423. Although the specification recommends a maximum speed of 2 Mbps, EIA-530 is used successfully at 4 Mbps and at even faster speeds over short distances. EIA-530 is used primarily in the United States.
The EIA-530 adapter cable is available in DTE mode only. The router (FSIP) end of the EIA-530 adapter cable is a high-density 60-pin plug. The opposite (network) end of the adapter cable is a standard DB-25 plug commonly used for EIA/TIA-232 connections. Figure 2-40 shows the DB-25 connector at the network end of the adapter cable. For cable pinouts, refer to the appendix "Cabling Specifications."
Figure 2-40 : EIA-530 Adapter Cable Connector, Network End (Available in DTE Only)
M3 Metric Thumbscrew Replacements
A pair of metric thumbscrews is included with each port adapter cable except V.35. If you will connect serial cables to remote devices that use metric hardware, replace the standard 4-40 thumbscrews at the network end of those cables with the M3 thumbscrews. Refer to the section "Connecting to Metric-Based Devices" in the chapter "Installing the Router" for replacement instructions.
You will need a T3, E3, or SONET STS-1 DSU and HSSI interface cable to connect the HIP with the external network. The HIP HSSI interface port is a 50-pin SCSI-II-type receptacle. The HSSI interface cable comprises 25 twisted pairs and a 50-pin plug at each end. Figure 2-41 shows the connector that is at both ends of the cable. Although the HSSI cable is similar to a SCSI-II cable, it is not identical; you cannot substitute a SCSI-II cable for a HSSI interface cable. (See the following Caution.)
Figure 2-41 : HSSI Interface Cable Connector
A null modem cable (CAB-HNUL) allows you to connect two routers directly back to back between an available HSSI port on each. This setup allows you to verify the operation of the HSSI port or to directly link the routers in order to build a larger node. The null modem cable uses the same 50-pin connectors as the HSSI interface cable, but the signals are wired differently. For instructions for connecting a null modem cable, refer to the section "HSSI Connections" in the chapter "Installing the Router." For the cable pinouts, refer to the appendix "Cabling Specifications."
Console and Auxiliary Port Connection Equipment
The RSP2 contains two EIA/TIA-232 ports: a DCE-mode console port (DB-25 receptacle) and a DTE-mode auxiliary port (DB-25 plug). These are asynchronous ports (unlike the synchronous FSIP serial ports), so be sure that any devices you connect to these ports are asynchronous. Asynchronous transmission uses control bits to indicate the beginning and end of characters instead of a precise clock signal. Synchronous transmission uses precise timing to synchronize transmissions between the transmitter and receiver, and maintains separate clock and data signals.
You will need a console terminal to configure the interfaces and bring up the system. You also need an EIA/TIA-232 DCE console cable to connect the terminal to the console port on the RSP2. After you establish normal operation, you can disconnect the terminal. Both ends of the console cable should be EIA/TIA-232 plugs to enable you to connect to the RSP2 DCE console port DB-25 receptacle and to the DB-25 receptacles used on the DTE ports on most terminals. Before you connect a terminal to the console port, configure the terminal to match the router console port as follows: 9600 baud, 8 data bits, no parity, and 2 stop bits (9600 8N2).
The auxiliary port is a DTE DB-25 plug that you can use to connect an asynchronous modem, another router, a CSU/DSU, or other DCE equipment. You also must supply your own interface cable between the auxiliary port and the equipment you are connecting. For console and auxiliary port pinouts, refer to the appendix "Cabling Specifications."
The chassis is fully assembled at the factory; no assembly is required except to install power supplies and attach the cable-management bracket. Following are the tools and equipment you will need:
To perform maintenance on chassis components, or to replace FRUs, you need the following tools:
Initial Configuration Information
After you install the chassis and verify that all the hardware is operating properly, you must configure the system and individual interfaces before you can connect to external networks. You can use the setup command facility or standard configuration commands to enter the configuration information.
Before you begin, you should be prepared with global (system-wide) parameters such as host names, passwords, and routing protocols, and with configuration information for each interface such as addresses, rates or speeds of operation, routing protocol specifics, and so on.
Following is some of the information you are likely to need, depending upon your configuration:
For complete configuration instructions, refer to the Router Products Configuration Guide, which is available on UniverCD or in print.
Use the Router Installation Checklist in Table 2-15 to assist you with your installation and to provide a historical record of what was done, by whom, and when. Make a copy of this checklist and indicate when each procedure or verification is completed. When the checklist is completed, place it in your site log (described at the end of this chapter) along with the other records for your new router.
Table 2-15 : Router Installation Checklist
Unpacking instructions are provided in the Unpacking Instructions posted on the outside of the shipping container; you should have already read that document and followed the procedures.
Proceed to the section "Checking the Contents" to verify the contents.
Following is the procedure for checking the contents of the shipping container. Use the Router Installation Checklist in Table 2-15, the Component List in Table 2-16, and the record of your order to ensure that you received all the components you ordered.
Table 2-16 lists all of the standard components that are included with the router and the optional equipment available. Check each item on the Component List as you unpack and verify it. Insert the completed checklist into the site log (which is described in the following sections).
A site log provides a historical record of all actions relevant to the router operation and maintenance. Keep your site log in a common place near the chassis where anyone who performs tasks has access to it. Site log entries might include the following:
Table 2-17 shows a sample site log page. Make copies of the sample or design your own site log to meet the needs of your site and equipment.
Figure 2-42 : Cisco 7513 Interface Processor Slot Numbering---Use with Table 2-18
Table 2-18 : Port and Slot Configuration Worksheet---Refer to Figure 2-42
Copyright 1988-1996 © Cisco Systems Inc.
Parameter
10BASE-5
10BASE-2
Cable diameter
0.4 in. (1 cm)
0.25 in. (0.6 cm)
Max. segment length
1640 ft. (500 m)
656 ft. (200 m)
Max. connections (taps) per segment
100
30
Min. connection (tap) spacing
8.2 ft. (2.5 m)
1.64 ft. (0.5 m)
Parameter
RJ-45
MII
Cable specification
Category 51 UTP2, 22 to 24 AWG3
Category 3, 4 or 5, 150-ohm UTP or STP or multimode optical fiber
Maximum cable length
--
0.5 m (1.64 ft.) (MII-to-MII cable4)
Maximum segment length
100 m (328 ft.) for 100BASE-TX
1 m (3.28 ft.)5 or 400 m (1,312 ft.) for 100BASE-FX
Maximum network length
200 m (656 ft.)5 (with 1 repeater)
--
1 EIA/TIA-568 or EIA/TIA-568 TSB-36 compliant.
2 Cisco Systems does not supply Category 5 UTP RJ-45 or 150-ohm STP MII cables. Both are commercially available.
3 AWG = American Wire Gauge. This gauge is specified by the EIA/TIA-568 standard.
4 This is the cable between the MII port on the FEIP port adapter and the appropriate transceiver.
5 This refers specifically to any two stations on a repeated segment.
100BASE-T
Data rate (Mbps)
100
Signaling method
Baseband
Maximum segment length (meters)
100
Media
UTP1
Topology
Star
1 UTP = unshielded twisted pair.
Connection Type
BNC
Twinax
Balanced
--
300 meters (m)
Unbalanced
600m
--
Transceiver Type
Max. Distance Between Stations
Single-mode
6.2 miles (up to 10 km)
Multimode
1.2 miles (up to 2 km)
Rate (bps)
Distance (Feet)
Distance (Meters)
2400
200
60
4800
100
30
9600
50
15
19200
25
7.6
38400
12
3.7
56000
8.6
2.6
Rate (bps)
Distance (Feet)
Distance (Meters)
2400
4100
1250
4800
2050
625
9600
1025
312
19200
513
156
38400
256
78
56000
102
31
128000
76
23
256000
50
15
1544000 (T1)
50
15
2000000
40
12
4000000
25
8
Transceiver Type
Maximum Distance between Stations1
Single-mode
Up to 9 miles (14.8 kilometers)
Multimode
Up to 1.5 miles (2.4 kilometers)
1 Table2-8 gives typical results. You should use the power budget calculations to determine the actual distances.
Single-Mode
Multimode
Attenuation
0.5 dB
1.0 dB/km
Dispersion Limit
No limit
500 MHz/km1
1 The product of bandwidth and distance must be less than 500MHzkm.
Link Loss Factor
Estimate of Link Loss Value
Higher order mode losses
0.5 dB
Clock recovery module
1 dB
Modal and chromatic dispersion
Dependent on fiber and wavelength used
Connector
0.5 dB
Splice
0.5 dB
Fiber attenuation
1 dB/km
Single-Mode
Multimode
PT
--18.5
--15
PR
--30
--28
PB
--11.5
--13
Specifications
Minimum
Maximum
Temperature, ambient operating
32°F (0°C)
104°F (40°C)
Temperature, ambient nonoperating and storage
--4°F (--20°C)
149°F (65°C)
Humidity, ambient (noncondensing) operating
10%
90%
Humidity, ambient (noncondensing) nonoperating and storage
5%
95%
Altitude, operating and nonoperating
Sea level
10,000' (3050 m)
Vibration, operating
5--200 Hz, 0.5 g (1 oct./min.)
--
Vibration, nonoperating
5--200 Hz, 1 g (1 oct./min.) 200--500 Hz, 2 g (1 oct./min.)
--
IEEE 802.3
Ethernet
10BASE-5
10BASE-2
10BASE-T
Data rate (Mbps)
10
10
10
10
Signaling method
Baseband
Baseband
Baseband
Baseband
Maximum segment length
500 m (1,640 ft.)
500 m (1,640 ft.)
185 m (607 ft.)
100 m (328 ft.) (UTP)
Media
50-ohm coax (thick)
50-ohm coax (thick)
50-ohm coax (thin)
Unshielded twisted pair (UTP)
Topology
Bus
Bus
Bus
Star
Network Type
Data Rates
Stations/ Segment
Topology
Media
Signaling
Access Method
Encoding
IBM Token Ring network
4, 16 Mbps
260 shielded twisted pairs 72 unshielded twisted pairs
Star
Twisted pair
Baseband
Token passing
Differential Manchester
IEEE 802.5 network
4, 16 Mbps
250
Not specified
Not specified
Baseband
Token passing
Differential Manchester
Task
Verified by
Date
Date router received
Router and all accessories unpacked
Types and numbers of interfaces verified
Safety recommendations and guidelines reviewed
Router Installation Checklist copied
Site log established and background information entered
Site power voltages verified
Site environmental specifications verified
Required passwords, IP addresses, device names, and so on, available1
Required tools available
Network connection equipment available
Cable management brackets installed (optional but recommended)
Router mounted in rack (optional)
AC power cable(s) connected to AC source(s) and router; retention band(s) secured
DC power cable(s) connected to DC source(s) and router; strain relief secured
Captive installation screws on processor modules and power supplies checked
Port and Slot Configuration Worksheet completed (optional)
Network interface cables and devices connected
ASCII terminal attached to console port
Console port set for 9600 baud, 8 data bits, no parity, and 2 stop bits (9600 8N2)
System power turned on (DC OK indicator(s) is on)
System boot complete (RSP2 normal LED is on)
RSP2 and all interface processors operational (enabled LEDs are on)
Console screen displays correct hardware configuration (displayed after system banner)
System ready for global and interface-specific configuration
1 Refer to the related software documentation for first-time software configuration requirements.
Component
Description
Rec'd
Chassis
Cisco 7513 router chassis
Accessories
The following accessories may arrive in separate shipping containers:
Rack-mount kit
Rack-mount kit hardware described in documentation for EFT-RMK and ACS-7513-RMK
Cable management kit
One bracket
Power cable
One AC cable per power supply (you supply DC cables)
EIP and FEIP port jackscrews
One jackscrew conversion kit for each Ethernet and Fast Ethernet port
FSIP interface cables
Verify that you receive 1 of the following adapter cables for each FSIP port:
EIA/TIA-232 DTE or DCE serial port adapter cable, 1 per port required
EIA/TIA-449 DTE or DCE serial port adapter cable, 1 per port required
V.35 DTE or DCE serial port adapter cable, 1 per port required
X.21 DTE or DCE serial port adapter cable, 1 per port required
EIA-530 DTE serial port adapter cable, 1 per port required
One pair of M-30 metric thumbscrews with each cable type except V.35
Optional cables
AUI or Ethernet transceiver cable, 1 per EIP port required;
RJ-45 or MII cable for each FEIP 100BASE-T port
Token Ring interface cable, 1 per TRIP port required
FDDI interface cables, 1 or 2 multimode, 2 or 4 single-mode for each FIP;
optical bypass switch for each CX-FIP-MM and CX-FIP-SS
HSSI interface cable, 1 per port required
Null modem cable for back-to-back HSSI connections
MIP cables, 1 per port required
AIP cables and types, 1 per AIP port required
Optional equipment
Ethernet and Fast Ethernet transceiver or 802.3 attachment unit
MAU, CSU/DSU for network connections
Documentation1
Router hardware and software document set or UniverCD if ordered
System components:
Processor slots should contain an RSP2 and some combination of interface processors or blank interface processor fillers
RSP2
Installed in either of the RSP2 slots (slot 6 or 7)
AIPs
Enter slot locations and port addresses on Configuration Worksheet
CIPs
Enter slot locations and port addresses on Configuration Worksheet
EIPs
Enter slot locations and port addresses on Configuration Worksheet
FEIPs
Enter slot locations and port addresses on Configuration Worksheet
FIPs
Enter slot locations and port addresses on Configuration Worksheet
FSIPs
Enter slot locations and port addresses on Configuration Worksheet
HIPs
Enter slot locations and port addresses on Configuration Worksheet
MIPs
Enter slot locations and port addresses on Configuration Worksheet
TRIPs
Enter slot locations and port addresses on Configuration Worksheet
1 Titles and quantities of documents will vary; documentation no longer ships with every system by default. You must specify the type and quantity of documentation sets when you order the hardware. (See the Note in the section "Checking the Contents" in this chapter.)
Date
Description of Action Performed or Symptom Observed
Initials
For
Page
Port
Slot 0
Slot 1
Slot 2
Slot 3
Slot 4
Slot 51
Slot 8
Slot 9
Slot 10
Slot 11
Slot 12
1
2
3
4
5
6
7
8
Router Name
Location
Serial Number
1 Slots 6 and 7 are reserved for the RSP2.
