The IPX supports a wide range of narrowband and broadband applications for both enterprise networks and service provider networks. In a multiservice environment, the IPX allows you to easily and cost-effectively launch new services and expand system capacity to meet growing demands. Similarly, as technologies evolve and WAN bandwidth increases, the IPX provides you with seamless growth and migration.

The IPX, IGX, and BPX Service Node share many of the same core capabilities and advanced networking features including the following:

• OptiClass class-of-service features

• ForeSight traffic management and congestion avoidance

• FairShare per-virtual-circuit queuing and rate scheduling

• AutoRoute connection management

The IPX lets you migrate from narrowband speed to broadband ATM on the same platform, providing unmatched WAN investment protection.

• 100 percent component redundancy

• Extensive background diagnostics

• Hot card swapping

• Rapid power failure recovery

• Background software download

• Firmware, not hardware, upgrades (remote download)

• Class B EMI certified enclosures

• Hard and soft alarm interfaces, including "call home" auto-dial modem features

• Minimum internal cabling

• Integrated grounding wrist straps

All switches use a midplane design with front cards performing processing functions and back cards providing interfacing and physical connectivity. This allows most system maintenance to be performed at the front cards, without disconnecting interface cables.

Voice activity detection uses the latest digital signal processing techniques to distinguish between silence and speech on a voice connection. Voice activity detection only generates traffic (cells) onto the network during speech, so typically achieves at least a two-to-one savings. This is possible because most voice conversations are 60 percent silence; one person listens while the other person speaks, and the speaker usually pauses between sentences. Together, ADPCM and voice activity detection over ATM achieve up to eight-to-one savings over uncompressed voice traffic.

• Standard voice switching

Channelized data PADs (CDP) are available for the IPX with E1, T1, or J1 ADPCM voice compression interfaces. Voice activity detection, which provides silence suppression, is also standard on these interfaces. Optional call switching is available.

The CDP operates with either a T1 (BC-T1), E1 (BC-E1), or J1 (BC-J1) back card. This module can be used for voice traffic, data traffic, or a combination of both. It provides a-law to u-law conversion and voice compression capability, and channelized data (up to 8 DS-0 bundles).

The CDP operates with either a BC-T1, BC-E1, or BC-J1 back card and offers a dual-purpose front card; termination of T1, E1, or J1 circuit line (communication line to CPE); circuit line use for voice traffic or data alone, or a combination of voice and data; voice mode channel default; and a-law with 56/64 x n data rates.

The IPX includes options for external or internal clocking on a port-by-port basis. The "software break-out box" feature allows the Electronics Industries Association (EIA) control leads on any data port of any node in the network to be viewed and manipulated in real time from the StrataView Plus network management console.

The IPX provides for suppression of repetitive patterns like idle flag conditions in SDLC and HDLC protocols. Repetitive pattern suppression increases efficiency of data connections up to 128 kbps. This algorithm effectively compresses data by up to four times by removing repetitive patterns such as "7E" flags sent by devices when they have no new traffic. Repetitive patterns are reproduced at the far end of repetitive pattern suppression connections, so connected devices remain unaffected.

The circuit-switched data services include the low-speed data packet PAD (LDP), synchronous data PAD (SDP), and channelized data PAD (CDP).

• The LDP includes a programmable communications processor, up to eight data ports, support for EIA/TIA-232 ports, data ranges up to 19.2 kbps per port, asynchronous or synchronous data support, and a low-speed data interface back card for physical and electrical connection interface support.

• The SDP includes a programmable communications processor; up to four data ports; one to four high-speed data channels that support V.35, X.21, V.36, EIA/TIA-449, and EIA/TIA-422; synchronous data protocol support; speeds from 1.2 kbps to 1.344 Mbps on all ports; error link monitoring; and a synchronous data interface back card that provides direct connection to the SDP physical and electrical interface.

• The CDP includes a dual-purpose front card; termination of T1, E1, or J1 circuit line (communication line to CPE); circuit line use for voice or data traffic alone or a combination of voice and low-speed/high-speed data; channelized data input support including 8 DS-0 per bundle and 56/64 x n data rates; full T1/E1 support with TDM transport license; and DS-0(A) support.

• Network trunk card (NTC)

The NTC coordinates the transmission of FastPackets across a trunk line to another Cisco node and offers cell-switched narrowband trunking with OptiClass CoS features, low delay over narrowband trunks, extraction of clocking from the trunk, and trunk usage statistics collection.

The NTC works with the T1 interface card (BC-6271A-T1), E1 interface card (BC-6171A-E1), Y1 interface card (BC-550150-Y1), subrate interface card for unframed transmission services (BC-6083A-SR), and full or fractional service configurable back cards.

• ATM internetworking trunk (AIT)

The AIT provides a broadband trunk interface enabling the IPX to use standard ATM cell relay protocol over T3/E3 trunks and to support E3, T3, E2, and HSSI; trunk rates as low as one T1/E1 rate; migration up to T3/E3 rates in T1/E1 increments with minimal downtime for traffic rerouting; a BTM front card and either a BC-571110A-T3, BC-571210A-E3, BC-571310A-E2, or BC-571410A-HSSI back card; and full CCITT ATM-compliance.

• FastPAD trunk card (FTC)

The modular PCS hardware lets you tailor each IPX node for specific applications. Modules are available with V.24/V.28, V.11, or V.35 DCE and/or DTE interfaces. For applications requiring multiple types of interfaces, interface daughter boards can be mixed and matched on a per-interface basis. You can insert up to four PCS modules into a PCS shelf. Modules can be hot-swapped without affecting service to other ports on the shelf.

PCS ports offer the following features:

• Conformance to all ANSI T1.606/.607/.618 and CCITT I.122/Q.933 standards

• Full implementation of Local Management Interface (LMI)

• Enhancements incorporated in ANSI and ITU standards

• Integrated frame forwarding for efficient transport of SDLC- or HDLC-framed traffic over Frame Relay on all port types at speeds up to 384 kbps

AutoRoute end-to-end connection management software automatically routes and reroutes virtual connections over optimal paths through the network. It keeps traffic moving over the shortest paths while guaranteeing quality of service for each connection. AutoRoute automatically reroutes virtual circuits to alternate paths if a trunk or switch fails. AutoRoute also tracks resources designated to individual connections to prevent overloading of individual trunks, ensuring high levels of network reliability and availability. AutoRoute eliminates the need to manually manage virtual circuits and allocate bandwidth, reducing network operating costs.

The OptiClass class-of-service features offer enterprise network managers and service providers several classes of service that can be assigned to specific connections. With OptiClass, you can assign minimum bandwidth guarantees for each connection, ensuring that services are delivered with the appropriate quality of service required. Together with AutoRoute, OptiClass automatically ensures quality of service for each application, resulting in higher performance and throughput. With OptiClass, unused bandwidth on network trunks and ports is also made available to any connection that can use it. OptiClass also gives network managers the flexibility to add new services, enabling service providers to more quickly deploy new services.

ForeSight bandwidth optimization and congestion avoidance software continuously monitors trunk use to adjust bandwidth to all connections, proactively avoids queuing delays, and virtually eliminates cell loss. It enables up to 95 percent trunk utilization, compared with the 50-70 percent use experienced when open-loop mechanisms are used alone in non-ForeSight ATM and frame-switching systems.

This allows a service provider to deliver additional services, resell spare capacity, and scale the network without large additional capital investment. It permits enterprise network managers to significantly reduce networking costs while delivering greater network functionality and higher application performance. It ensures maximum bandwidth to all connections while proactively avoiding the possibility of queuing delays and cell discard. ForeSight is the industry's first implementation of the new rate-based traffic management specification defined by ATM Forum Specification V.4.0, and the only such mechanism available for Frame Relay.

FairShare is a patented per-virtual-circuit queuing and rate scheduler. It allocates bandwidth fairly among network users by providing a virtual "firewall" between connections and service classes. Unlike a shared buffer scheme, per-virtual-circuit queuing prevents one misbehaving connection from affecting the performance of others.