This chapter provides an overview of the applications that make up the WAN Design Tools and of the Cisco products supported by the Network Modeling Tool (NMT).
The primary application of the WAN Design Tools is the Network Modeling Tool. The NMT helps you design an efficient network topology based on the Cisco Stratacom IGX switch, BPX switch, AXIS shelf, and IPX switch and provides configurations for each node based on the network connection requirements. NMT also models some edge equipment: the Cisco 3800 product line, the Port Concentrator Shelf (PCS), and the FastPAD. The NMT delivers accurate trunk loading and correct node configuration. It ensures that node and card limits are observed and provides part numbers for ordering equipment.
The other WAN Design Tools enable the exchange of information between the NMT and other applications. These tools include the Configuration Extraction Tool (CET) and the two Conversion Plug-ins, the Spread Sheet Interface (SSI) and Third-Party Interface (TPI).
Figure 1-1 shows the relationship between the applications that make up the WAN Design Tools.
The NMT enables you to model both simple and complex networks. The program processes information provided by you and returns a proposed configuration. This configuration can then be modified and reprocessed to add redundant links (FastPacket trunks, for example), support additional sites, and so forth. You can also perform failure analysis of the network model by failing selected links and then evaluating the rerouting capability of the remaining links.
The NMT is menu driven, and requires that you describe your network or proposed network by entering into tables information about sites, nodes, traffic types, transmission costs, and much more.
Although only a few fields need to be completed in order for the NMT to generate a configuration, you will create the best configuration if you have a good knowledge of computer networks, including Frame Relay networks, tiered networks, and the role of feeders. In addition, by entering precise values for optional fields, such as power supply and cabinet type, the NMT will provide you with a precise parts list that you can use to order Cisco products.
After the NMT processes your data, it provides you with configuration information in the following form.
- Updated tables--Modifies your configuration tables as necessary to create a working configuration.
Figure 1-1: Relationship between the WAN Design Tools
- Reports--Provides a series of reports that describe links, nodes, part numbers, costs, and so on.
- Graphical display--Displays your network design graphically with node icons and maps.
The NMT always selects the newest available parts for a function, based on the software release you specify. You can explicitly request older cards from the input tables. Some obsolete parts are not supported.
The CET and Conversion Plug-ins enable you to model complex networks by allowing you to exchange data between the NMT and related software.
The CET reads the database of a StrataView Plus system, and creates an NMT configuration file with all critical topology and connection information. For more information see the chapter "Configuration Extraction Tool."
The TPI conversion plug-in translates NMT data into WANDL format. WANDL is a design product that helps you optimize generic networks. TPI also provides translation from the WANDL-to-NMT configuration files. For more information, see the chapter "Third-Party Interface."
The SSI conversion plug-in translates the NMT configuration file tables into standard DBF and XLS formatted files, for use in other systems. It also supports an Excel XLS interface for entering, modifying, and analyzing network data. Several NMT reports are also available in DBF and XLS. For more information, see the chapter "SpreadSheet Interface."
The NMT is a constantly evolving software product. New functionality is added in each release to accurately reflect the current capabilities of Cisco equipment:
- IPX switch--A multi-service narrowband ATM WAN switch that supports legacy and emerging applications while taking advantage of ATM technology over subrate, narrowband E1 and T1, and broadband E3 and T3 trunks. The IPX switch is used as the basis for a leased-line network, as an intelligent access device to high-speed public digital services such as ATM, or in a hybrid application using both.
- IGX switch--A multi-service ATM networking switch that provides interfaces to support legacy and emerging broadband applications. It supports ATM technology over subrate, narrowband E1 and T1, and broadband E3 and T3 trunks. The IGX switch is used as the basis for a leased-line campus, metropolitan area network (MAN) and WAN network, as an intelligent access device to high speed-public digital services such as ATM, in a hybrid application using both, and as a WAN service switch.
- BPX switch--A standards based high-capacity (9.6 Gb) broadband ATM switch that provides backbone ATM switching and delivers a wide range of user services. Fully integrated with the IPX and IGX switches, the BPX switch provides broadband ATM services when ASI and BXM cards are used. It also provides a variety of narrowband services; these services are provided by tiered network configurations that use IPX switches and AXIS feeders.
- The BPX switch supports the high density Broadband Switch Module (BXM) cards that provide standard interfaces for connecting to cell-based equipment by way of the ATM User-Network Interface (UNI).
- BXM DS3/E3 supports E3/DS3 native ATM access and trunk ports.
- BXM 155 supports OC-3/STM-1 native ATM access and trunk ports.
- BXM 622 supports OC-12/STM-4 native ATM access and trunk ports.
- BXM cards also support ATM Frame Relay networks and services and enable configuration of permanent virtual circuits (PVCs) or switched virtual circuits (SVCs) for the following defined service classes:
- Constant bit rate (CBR)
- Variable bit rate (VBR)
- Unspecified bit rate (UBR)
- Available bit rate (ABR)
- Cisco StrataCom AXIS Shelf--Enables a wide range of user services to be supported by the BPX service node. Interfaces supported by the NMT include the following:
- Frame Relay
- ATM User-Network Interface (UNI)
- Circuit emulation
- n x T1/E1 inverse multiplexing for ATM (IMATM AUSM-8) UNI
- 3T3 interface using the SRM-3T3 module
- Cisco 3800--A family of multiservice, integrated access platforms that enables the integration of all traffic--legacy data, LAN traffic, voice, fax, and video--over a single network backbone. The Cisco 3800 can be deployed in private or public networks, reducing equipment and connection costs, simplifying network management, and improving application performance.
- The Cisco 3800 also links different data sources, PBXs, LAN segments, and internetworking devices, giving network managers the flexibility to deploy a single-vendor solution from branch to branch, network-wide.
- Port Concentrator Shelf--Increases Frame Relay port capacity and speed range on an IGX or IPX switch. A fully loaded PCS expands the capacity of each Frame Relay card in an IGX or IPX switch to 44 ports. For example, using the PCS the IGX 8 or IPX 8 switch can support up to 264 physical ports using the PCS. IGX and IPX 16/32 switches can also be used with the PCS, expanding Frame Relay port capacity to more than 1,200 physical ports on one node. This makes the combination of an IGX or IPX switch and a PCS suitable for delivering high port density in Frame Relay service or enterprise networks. The PCS also includes the following features:
- Conforms to all ANSI T1.606/.607/.618 and ITU-T I.122/Q.933 standards.
- Supports full implementation of Local Management Interface (LMI).
- Supports enhancements incorporated in ANSI and ITU standards.
- Supports integrated Frame Relay access devices (FRADs) or frame forwarding for efficient transport of SDLC or HDLC-framed traffic over Frame Relay on all port types at speeds up to 384 kbps.
- FastPAD--FRADs that provide voice and data integration. They can be used for Frame Relay applications, Frame Relay switching, X.25 switching, and X.25 PAD applications. Built on X.25 and Frame Relay switching engines, FastPAD devices are well-suited for networks that require both X.25 and Frame Relay.
