Table of Contents

Product Overview
Key Features and Benefits

Physical Design
Multiservice Functionality
Scalability
Common Equipment

ATM Shelf Controller (ASC)
Service Resource Module (SRM)
SRM-3T3

Trunking Options

Broadband Network Module (BNM)
BNM-155 Trunk Card
Inverse Multiplexing for ATM Trunk Module (IMATM)
Configuration Examples
Cisco BPX 8600 Series Switch
Remote Locations
Standalone MGX 8220 edge concentrator

Service Modules

T1/E1 ATM UNI/NNI Service Modules
Circuit Emulation Service Module (CESM)
Module Configurations
Frame Relay Service Module (FRSM-8T1/E1)
FRSM-8 Service Module (FRSM-8T1-C or FRSM-8E1-C)
High-speed FRSM (FRSM-HS1)

Value-Added Services

Enhanced LMI (ELMI)
Extended ForeSight
Central Office Frame Relay Access Device (CO FRAD)

Specifications
Ordering Information

Cisco MGX 8220 — Edge Concentrator

Product Overview

Cisco MGX 8220 is a standards-based, integrated ATM edge concentrator that provides aggregation of a variety of services to a standard ATM User-Network Interface (UNI) or Network-to-Network Interface (NNI) port. The MGX 8220 edge concentrator can be used as an integrated or remote adjunct shelf for Cisco`s ATM switch product lines. In addition, it can serve as a standalone unit that aggregates traffic for transmission to and from an ATM network.

The Cisco MGX 8220 adapts incoming data to 53-byte ATM cells using industry-standard ATM Adaptation Layers (AAL) for transport over the ATM network. By integrating narrowband and broadband interfaces on a single platform, service providers can fully utilize the node capacity, incrementally expand capacity as needed, and cost-effectively provide services to an almost unlimited number of subscribers.

Key Features and Benefits

Physical Design

The MGX 8220 edge concentrator is a self-contained, 8.75-in. deep, 19-in. or 23-in., rack-mountable EMI (electromagnetic interference enclosure). The shelf chassis has 16 slots; each slot can accommodate a front and a back card with six slots reserved for common equipment modules. The other 10 slots are available for any service (I/O) module. The MGX 8220 edge concentrator supports up to 80 T1 or E1 user interfaces, or up to 2480 64 kbps DS-0 interfaces.

The front cards are function modules — cards that perform complex functions; for example, Frame Relay-to-ATM conversion. Each function module (front card) can have a corresponding back card — a line module that provides physical interfaces tone or more transmission lines connected to the MGX 8220 edge concentrator (for example, the trunk line to a Cisco BPX 8600 wide-area switch or eight customer T1 lines). The front card communicates with the back card via a "midplane." This midplane design allows replacement or upgrading without disturbing the physical cabling.

The chassis is powered by either -48 VDC or 220 VAC sources. The DC version includes DC power entry modules (optionally redundant) that can be mounted in the shelf. The AC version uses an external rack-mounted AC power module — also optionally redundant. Both versions use a rack-mounted cooling assembly. Multiple MGX 8220 shelves can be mounted in the same rack, sharing power and cooling assemblies.

Multiservice Functionality

The MGX 8220 edge concentrator allows customers to reduce equipment costs, make efficient use of trunking resources, protect their investments in existing premises equipment, and rapidly deploy new services as required. Services and interfaces supported include the following:

• Frame Relay UNI/NNI

  • 56 kbps, n x 64 kbps, T1, E1, HSSI, X.21

  • Frame Relay to ATM network and service internetworking

• High-speed Frame Relay

• ATM Frame UNI

  • 56 kbps, n x 64 kbps, T1, E1, HSSI, X.21

• ATM UNI/NNI

  • T1, E1, n x T1 (IMA), n x E1 (IMA)

• Frame forwarding

  • 56 kbps, n x 64 kbps, T1, E1, HSSI, X.21

• Circuit emulation

  • T1, E1, nx64 kbps

• ISDN switched access

• SNA services

  • SDLC and bisync, DS-0, DS-0A

Physical connectivity is provided through individual HSSI, X.21, T1, or E1 ports, V.35, or through channelized T1/E1 interfaces.

Scalability

The MGX 8220 edge concentrator aggregates traffic from as many as 80 T1 or E1 ports onto a single port of a multiport broadband trunk card. This high port density maximizes use of the Cisco BPX 8600 series high-capacity switch fabric. Each 9-in. rack-mount shelf supports up to 80 DS-1 or E1 ports or more than 2000 64 kbps users. The MGX 8220 edge concentrator has a compact footprint that minimizes the space required within central offices.

Common Equipment

Common equipment modules are the shared resources that perform administrative, network management, and communication tasks and provide 1:n redundancy of service modules and transmission of aggregated traffic to and from the ATM node. The common equipment modules can be configured for 1:1 redundancy.

ATM Shelf Controller (ASC)

The ASC performs all shelf-management functions, including intercard communications. The following external interfaces are provided for control access to the ASC:

• AUI 802.3 interface

• EIA/TIA-232 control port

• EIA/TIA-232 maintenance port

The ASC provides the following functionality:

• Configures and controls individual card on the Cisco MGX 8220 shelf

• Communicates with the network manager to receive control information and report statistics

• Performs shelf-management functions

• Provides common equipment module redundancy functions and initiates common equipment card switchover upon failure

• Controls the broadband network module (BNM)

• Controls the service resource module (SRM)

• Provides an AUI (attachment unit interface) for LAN connectivity

• Provides an RS-232 control port for SLIP access for routine maintenance and additional control

• Provides RS-232 maintenance port for direct serial access for troubleshooting

Service Resource Module (SRM)

The SRM-T1/E1 is an optional common equipment module that provides the following functions:

• 1:n redundancy of the T1 service modules. One standby card can spare up to nine active cards.

• BERT (bit error rate tester) generation and test capability for individual DS-1 or subrate ports (n x DS-0)

• Extended loopback code-generation capabilities for individual DS-1 or subrate streams

The SRM is 1:1 redundant.

SRM-3T3

The SRM-3T3 service redundancy module provides bulk distribution of T1 circuits to the 4-port or 8-port T1 service modules. Rather than individually cable each of the 40 or 80 incoming T1/E1 lines to an MGX 8220 edge concentrator, the MGX 8220 backplane is designed with a distribution bus that allows an SRM-3T3 to distribute T1s received "in bulk" to T1-based service modules. This eliminates the need for T1 back cards for each service module and the associated cabling and potential overloading of the digital cross-connect system port.

The SRM-3T3 provides a method to bring in from one to three T3 interfaces that can be demultiplexed to their constituent T1s, providing up to 28, 56, or 80 T1s to be distributed to T1 service modules over the distribution bus. Both 4-port and 8-port service modules are supported in any combination.

The SRM-3T3 supports the following features:

• 1:1 redundancy of the SRM with Y-cabling

• The same features as the SRM-T1E1, including bit rate error test (BERT) and 1:n redundancy of T1/E1 service modules

• Spare service module that can be used to provide redundancy for both bulk-distributed and line-module-based service modules concurrently (a redundancy back card will be required for a spare service module providing redundancy for line module-based service modules)

• No back card required for T1 service modules that use bulk distribution

• Mix of service modules using bulk distribution with service modules using line modules in the same shelf

• Mix of 4-port and 8-port cards, with all 10 slots always available to service modules via either line modules or bulk

Trunking Options

Broadband Network Module (BNM)

The BNM provides the trunk interface to an ATM device. The MGX 8220 edge concentrator supports network modules at T3, E3, and OC-3/STM-1 speeds. In addition to transferring cells to and from the ATM platform, the BNM module polls each of the service modules to control access to the backplane. Each MGX 8220 edge concentrator must have at least one BNM and can be configured with an identical spare BNM.

The BNM performs the following functions:

• Controls cell flow between the trunk interface and other cards in the Cisco MGX 8220 shelf

• Directs cells to and from an ATM switch from and to the appropriate service cards

• Controls common equipment card set redundancy switchover and shelf mastership resolution with standby BNM (if present)

• Manages clock selection and synchronization for the MGX 8220 edge concentrator

• Class-of-Service queuing and queue service

• Provides CO-compatible alarm indication, controls, and relays

• Monitors MGX 8220 edge concentrator (voltage)

• Monitors MGX 8220 edge concentrator cooling fans and shelf air temperature

BNM-155 Trunk Card

The broadband network module, BNM-155, increases the bandwidth of the Cisco MGX 8220 feeder trunk to 155 Mbps, matching the bandwidth provided by the MGX 8220 edge concentrator backplane. It is compliant with SONET/STM-1 standards, and ATM UNI and NNI formats are supported for flexible connectivity options to an ATM switch.

The BNM-155 also increases the connectivity options for the MGX 8220 edge concentrator as an ATM access feeder to allow the MGX 8220 edge concentrator to interface to a Cisco BPX 8600 series switch via a BXM, to an IGX 8400 series switch, or to other ATM switches.

The BNM-155 supports the following features:

• OC-3/STM-1 155.52 Mbps (353,208 cell) interface

• BNM-155 front card, independent of interface type

• Supports 1:1 redundancy using Y-cabling

• Clocking source options include the OC-3/STM1 trunk, an external T1 or E1 external clock input (DB15 and BNC connectors), and an internal oscillator

• Supports ATM UNI and NNI cell formats

• Supports 256 virtual-path connections (VPCs) per slot

• Supports 10,000 VCCs per slot

• BNM-T3/E3 trunk card

Inverse Multiplexing for ATM Trunk Module (IMATM)

IMATM allows customers to grow beyond T1/E1 without having to make a large jump to T3.

IMATM cards are available in a T3-to-multiple-T1 version and an E3-to-multiple-E1 version, providing trunking between BPXs at up to 8 x T1 or 8 x E1 speeds.

IMATM and AUSM support ATMF compliant IMA specification 1.0. The IMATM is based on ATM cells and can support all ATM service classes and traffic types with Advanced CoS Management software that provides up to 16 programmable classes of service with standards-based quality-of-service (QoS) descriptors. It offers flexibility in provisioning and customizing services and in maintaining network efficiency.

Full resiliency is provided by supporting both one-for-one card redundancy and automatic adjustment of the IMA bandwidth to the number of available circuits.

• Cost-effective flexible bandwidth — from T1 or E1 to 8 x T1 or 8 x E1

  IMATM cards provide a smooth migration from narrowband to broadband ATM. You can configure a BPX trunk initially to use a single T1 or E1 line. The bandwidth can then be increased by one or more lines at a time until the break even point for broadband tariffs is reached at about eight lines.

  With IMATM cards in the MGX 8220 edge concentrator, Cisco BPX 8600 series switches can implement trunk bandwidths between T1/E1 and T3/E3 speeds. Interfaces on the BPX broadband shelf provide high-speed ATM connectivity for network segments with heavier traffic demands.

• Robust design — protects the system from circuit and card failures

  Cisco designed IMATM for fault tolerance as well as high performance. One of the inherent advantages of IMA over other inverse multiplexing techniques is its ability to route circuits over diverse paths using different clocks with the same nominal frequency. For example, a trans-Atlantic IMA trunk could be split across two carriers — each providing its own clock — with continued operation even if one of the carriers` circuits fails.

  IMA technology keeps traffic flowing even when an individual circuit fails. In a nonmultiplexed system, users of a given circuit might not be able to switch to a new path easily if their circuit goes out of service. In an IMA-based system, if one of the T1 or E1 links fails, all traffic on the trunk continues to flow over the remaining links. Even though the available bandwidth is reduced, users retain their network connectivity.

  IMATM cards support 1:1 card redundancy through Y-cabling of the interfaces. The T1 or E1 cabling is repeated for each T1/E1 in the IMA trunk.

• High speed — efficient multiplexed design that takes full advantage of all available bandwidth

  Cisco`s midband ATM technology enables connections to take full advantage of all available bandwidth. For example, a network segment with four T1 lines multiplexed together through IMATM cards can use all four lines to handle high traffic levels on a given connection.

  In comparison, when multiple independent (nonmultiplexed) T1 or E1 links are used between two switches, each connection is limited to a maximum speed of T1 or E1. If a given line experiences a burst of traffic that exceeds its available bandwidth, its throughput suffers. There is no way for it to route the excess traffic to another line.

Configuration Examples

Cisco BPX 8600 Series Switch

When configured as part of a Cisco BPX 8600 series wide-area switch, the MGX 8220 edge concentrator allows modular scaling of the capacity of the service node without requiring additional switches. All MGX 8220 edge concentrator shelves in a service node are logically managed as an integrated part of the service node.

Remote Locations

For remote locations with limited switching requirements, the Cisco MGX 8220 can be physically remote from the Cisco BPX 8600 series via IMA or broadband trunks.

Standalone MGX 8220 edge concentrator

The MGX 8220 edge concentrator is not limited to attachment to the Cisco BPX 8600 series switch. In standalone operation, the Cisco MGX 8220 trunk can attach to any ATM switch to provide service aggregation.

Service Modules

The MGX 8220 edge concentrator uses service modules and core cards to provide multiservice functionality.

T1/E1 ATM UNI/NNI Service Modules

The ATM UNI service module (AUSM-8) provides MGX 8220 edge concentrator support for ATM UNI services. This service module offers the following features:

• 8-T1 or E1 unchannelized ports

• ATM UNI and ATM NNI format

• 1000 virtual connections per 8-port card; 256 virtual connections per 4-port card

• Single-bit HEC error correction

• Per-virtual-circuit queues on input, at least 16 class-of-service queues per port for user data on output

• IMA UNI/NNI that allow each T1/E1 to be either configured as a normal T1/E1 UNI/NNI or assigned to an IMA group. ATMF compliant IMA support is provided on the 8-port AUSM.

• Automatic adjustment of IMA after failure of any number of T1/E1 circuits to continue operation over the remaining circuits

• AutoCard restore and 1:n redundancy

• Provides BERT and extended loopback pattern generation/verification (when a service redundancy module [SRM] is also installed in the MGX 8220 edge concentrator)

Circuit Emulation Service Module (CESM)

The CESM supports access for T1/E1-based circuit emulation service (CES) data, voice, and video. The CESM receives the T1 or E1 bit stream, buffers and converts it into ATM cells using AAL1 adaptation, and sends the cells to the broadband network module for transmission via the trunk interface to the ATM device.

The CESM-8 supports both channelized (nx64 kbps) and unchannelized (T1/E1) circuit-based equipment. In ATM Forum terminology, the terms structured data transfer (SDT) and unstructured data transfer (UDT) are used for channelized and unchannelized CE respectively.

Key features of the CESM-8 include:

• ATM Forum standards based AAL1 CE - v2.0

• Choice of structured or unstructured data transfer per physical interface

• Time slots need to be contiguous for nx64 kbps fractional T1/E1 service

• SF, ESF framing modes supported

• Synchronous clocking supported for both UDT and SDT

• Asynchronous clocking supported for UDT, with the following clock recovery methods:

  • SRTS

  • Adaptive

• ON/OFF Hook detection and silence suppression using CAS

Module Configurations

The following CESM configurations are available:

Frame Relay Service Module (FRSM-8T1/E1)

The FRSM multiplexes and demultiplexes frame traffic, including Frame Relay, FUNI, and other HDLC-derived data (frame forwarding). The FRSM performs adaptation, segmentation, and reassembly (SAR), and internetworking functions to convert traffic to and from ATM cells.

The FRSM includes the following features:

• FR-UNI, FR-NNI, and ATM FUNI interfaces and policing

• Frame Relay-to-ATM service and network internetworking

• ForeSight closed-loop rate control and per-VC queuing

• Wire-speed performance on all ports

• SVC and multicast support within Cisco service nodes

• Standard and enhanced LMI management interfaces (Annex A and Annex D)

FRSM-8 Service Module (FRSM-8T1-C or FRSM-8E1-C)

The port density of the T1/E1 Frame Relay service modules (FRSM-8) has increased from four to eight, with the same features available to both types of service modules. The FRSM-8 provides a platform that supports up to 80 Frame Relay T1s or E1s on a single MGX 8220 edge concentrator shelf with full 1:n redundancy support and full channelized T1/E1 support, at an aggressive price per port for real traffic mixes.

The FRSM-8T1/E1 includes the following features:

• Support for 8-port T1 or E1 FRSMs (fractional and channelized versions) via individual T1/E1 connectors or via the SRM for bulk distribution (T1 only)

• Support for the same 8-port back cards as the AUSM-8T1/E1

• A channelized card, allowing each of 8 T1s or E1s to be channelized and support multiple ports per physical interface, up to the bandwidth limitations of the line

• A fractional card supporting a single customer port per physical interface (n x 64 kbps)

• Up to 1000 connections per card

• 1:n redundancy using an SRM

High-speed FRSM (FRSM-HS1)

The high-speed Frame Relay service module (FRSM-HS1) supports higher-speed HSSI or X.21 interfaces. The FRSM-HS1/B service module supports V.35 interfaces.

The FRSM-HS1 supports the following features:

• Card throughput of 20 Mbps (bidirectional) at an average frame size of 130 octets

• HSSI line rates of up to 16 Mbps when a single port is configured per card. HSSI line rates of up to 8 Mbps when both HSSI ports are configured

• X.21 line rates of 1 port x 10 Mbps, 2 ports x 8 Mbps, 3 ports x 4 Mbps, or 4 ports x 4 Mbps

• Up to 1000 virtual connections in DTE and DCE modes

• 1:1 redundancy using Y-cabling

• All standard MGX 8220 edge concentrator FRSM features, including the same data link protocols as other FRSMs

• ForeSight integrated on the high-speed FRSM as a feature license

• FR-ATM network internetworking and service internetworking support

• Configuration of ATM Frame user network interface (FUNI) or ATM Frame NNI on a per-port basis

• Frame forwarding and FUNI support

Value-Added Services

Enhanced LMI (ELMI)

The enhanced Local Management Interface (ELMI) allows Frame Relay customer premises equipment (CPE) to exchange configuration information with the edge node of the network. Such configuration information includes LMI (Local Management Interface) protocols being provisioned or supported and the QoS parameters provisioned for every PVC. It also enables the network side to notify the CPE of any QoS changes. This enhancement simplifies the CPE configuration and guarantees configuration consistency between the CPE and the network.

LMI enhancements can be configured on a per-logical port basis to allow you tenable or disable ELMI per individual port. All service modules supporting FR LMI (Q.933 Annex A, ANSI T1.617 Annex D, or Cisco LMI), which includes FRSM 4T1/E1, FRSM 8T1/E1, and FRSM-HSI, support this enhancement.

Extended ForeSight

Extended ForeSight uses standards-based consolidated link-layer management (CCLM) messages to pass ForeSight congestion indications across Frame Relay UNI and NNI service interfaces. Extended ForeSight provides a powerful means for extending the range of ForeSight flow control beyond the network boundaries of a single carrier.

Central Office Frame Relay Access Device (CO FRAD)

CO FRAD supports SNA connectivity and allows service providers to offer legacy SNA access to Frame Relay or ATM networks for transporting SNA SDLC, or bisync traffic. It provides a high-density Frame Relay access-device capability that can be located at a central office. CO FRAD is provided in the AMGX 8220 edge concentrator, through the Frame Relay access service module (FRASM), and eliminates the need for a customer premises-based FRAD.

The FRASM card implements a high-density serial FRAD that can be located at a central office. FRASM enables legacy SNA/SDLC access to Frame Relay or ATM networks for transmitting SNA and bisync 3270 traffic. FRASM is an integrated Cisco MGX 8220 service module that eliminates customer premises-based FRADs and is used to migrate SNA traffic from leased lines to the more cost-effective solution of Frame Relay or ATM WAN without changing customer premises equipment.

CO FRAD includes the following features:

• The FRASM supports high-density Frame Relay concentration for SDLC and bisync devices. It can be used by service providers to provide an integrated platform to migrate SNA traffic from leased lines to Frame Relay/ATM WAN. FRASM implements standard RFC 1490 encapsulation for SNA over Frame Relay transport.

• Up to 8 channelized T1 interfaces with DS-0 and DS-0A channel format

• Supports access rates of 2.4K, 4.8K, 9.6K, 56K, 64K, and n*64 kbps

• Supports SDLC and bisync

• Supports multiple PUs over a single DS-0 or DS-0A port (multiple PVCs per port)

• Up to 192 SDLC or bisync ports per card

• Up to 1000 PVCs per card

• Up to 16 multidrop connections per port

The following end-to-end configurations will be supported by FRASM:

• SDLC tunnel with local acknowledgment (SDLC at both ends of the network)

• Bisync tunnel with local acknowledgment (bisync at both ends of the network)

• SDLC to boundary network node (BNN) conversion (SDLC at one end and Frame Relay BNN at the other)

Specifications

For software/feature licenses, see part number table below.

Ordering Information

Posted: Wed Sep 27 05:15:25 PDT 2000
Copyright 1989-2000©Cisco Systems Inc.