Cisco MGX 8800 Series Switches

Cisco MGX 8800 PXM1 Processor Switch Module


Data Sheet

Cisco MGX PXM-1
Processor Switch Module

The Cisco MGX PXM-1 Processor Switch Module is a combination ATM switching fabric, data processing, and ATM interface card used on the Cisco MGX 8230, 8250, and 8850 switches. The Cisco MGX PXM-1 Module combines a 1.2-Gbps shared-memory switching fabric with integrated trunking at speeds up to OC-12. The switching fabric provides 1.2 Gbps of nonblocking switching capacity, while the processor provides the control plane that delivers advanced IP+ATM networking software, diagnostics, and performance monitoring.

Key Features

  • Integrated switching, processing, and broadband interfaces, which provide high-performance switching and trunking on a single card

  • Route Processor Module (RPM) 1: Redundancy

  • 1.2 Gbps nonblocking switching

  • Integrated T3/E3, OC-3c/STM-1, OC-12c/STM-4 ATM trunking

  • Linear automatic protection switching (APS) for the Synchronous Optical Network (SONET) interfaces

  • Hot card insertion/removal

  • 1:1 hot-standby redundancy

  • User-selectable primary and secondary clock sources with graceful switchover

  • Internal Stratum-4 or optional Stratum-3, external building integration timing supply (BITS), or inband clock sources

  • Inband management or out-of-band via EIA/TIA-232 or 10BaseT control ports

  • Narrowband service modules

  • Broadband trunking support

  • Support for DS0 to OC-12c/STM-4 interfaces

Figure 1: Cisco MGX 8850 PXM-1 Processor Switch Module

The Cisco PXM-1 and MGX Universal Chassis provides a unified IP+ATM architecture that can deliver multiple services, from Frame Relay and circuit emulation services to IP VPNs, on a single chassis.

The Cisco MGX PXM-1 Module combines ATM switching and ATM trunking on a single card. The Cisco MGX PXM-1 trunk and UNI ports operate at the standard T3/E3 and SONET/Synchronous Digital Hierarchy (SDH) rate of 155.520 or 622.08 Mbps.

Technical Specifications

ATM Switch Fabric Card

  • Resides in slots 1 and 2 of the Cisco MGX 8230

  • Resides in slots 7 and 8 of the Cisco MGX 8850 and 8250

  • Supports hot insertion and removal

  • Supports 1:1 hot-standby redundancy

  • Offers R4700 MIPS CPU

  • Offers 1.2 Gbps worth of nonblocking switching

  • Provides 2.1-multigigabit hard drive

  • Provides full environmental monitoring of cabinet temperature, cooling fan speeds, and supply voltages

  • Provides four LED indicators

    • Card status

    • Major/minor network alarms

    • LAN control port activity detect

    • DC power status

Supports two back cards:

  • Upper back card supports the following functions:

  User and management interfaces
  • EIA/TIA-232 control port

  • EIA/TIA-232 maintenance port

  • 10BaseT Ethernet port

  Network synchronization for the shelf
  • T1/E1 BITS synchronization port

  • Stratum-4E clocking

  • Stratum-3 clocking (optional)

  • Conformance to ATT Pub. 62411

  Central office-compatible major/minor alarm interface
  • DB-15 connector

  • Major alarm audio

  • Major alarm visual

  • Minor alarm visual

  • Lower back card provides one of the following ATM interfaces:

    • Two-port T3/E3

    • Four-port OC-3c/STM-1

    • One-port OC-12/STM-4

Physical-Layer T3/E3 Interface

  • Two T3/E3 ports

  • Complies with ATM Forum UNI Specification Versions 3.0, 3.1

  • 1:1 PXM1 redundancy

Table 1: T3/E3 Interface Physical Characteristics
Characteristic T3 (DS3) E3 (34 Mbps)

Line Rate

44.736 Mbps ±20 ppm

34.368 Mbps ±20 ppm

Line Code



Cell Transfer Rate

96,000 cells/sec

80,000 cells/sec


ANSI T1.107, T1.107a

ITU-T G.804, G.832

Signal Level




ITU-T G.703




Cell Mapping





Physical Layer OC-3c STM-1 Interface

  • Four OC-3c/STM-1 (155.520-Mbps) ports

  • Trunk or port interface mode

  • Cell transfer rate of 353,208 cells per second

  • Compliant with SONET standards

    • Bellcore GR-253-CORE

    • ANSI T1.105

  • Compliant with SDH standards

    • ITU-T G.707, G. 708, and G.709

    • ITU-T G. 957, G.958

    • ITU-G.783 Annex-A

  • 1:1 PXM1 redundancy

  • ITU-G.783 Annex-A

Physical Layer OC-12c/STM-4 interface

  • One OC-12c/STM-4 (622.08-Mbps) port

  • Cell transfer rate of 1,412,832 cells per second

  • Compliant with SONET standards

    • Bellcore GR-253-CORE, TR-TSY-000020

    • ANSI T1.105

  • Compliant with SDH standards

    • ITU-T G.707, G.708, and G.709

    • ITU-T G.957, G.958

    • ITU G.783 Annex-A

  • 1:1 PXM1 redundancy

  • OC-12 fiber-optic interface options

Table 2: OC-3c STM-1 Interface Physical Characteristics
OC-3c/STM-1 Tx Power (dBm) Rx Range (dBm)
Back Card Source 1310 nm Min Max Min Max Physical Range (km)










Laser (Class 1)








Laser (Class 1)







Table 3: OC-12c/STM-4 Interface Physical Characteristics
OC-12c/STM-4 Tx Power (dBm) Rx Range (dBm)
Back Card Source Min Max Min Max Physical Range (km)

Laser 1310 nm








Laser 1310 nm







ATM Layer

  • Configurable for trunk and public or private User-Network Interface (UNI) application

  • UNI compliant to ATM Forum UNI Specifications V.3.0 and V.3.1, and ITU-T I.361 and I.432 specifications

  • Complies with standard usage parameter control (UPC) and connection admission control (CAC) per ATM Forum UNI Specification V.3.1 and ITU-T I.371

  • Supports virtual circuit connections (VCCs) and virtual path connections (VPCs) per ATM Forum UNI Specification V.3.1 and ITU-T I.371

  • Connections

    • 16,000 connections per chassis

    • 4,000 UNI connections per card

  • Virtual path identifier/virtual channel identifier (VPI/VCI) range for VCCs and VPCs: per UNI Specification 3.1

Traffic Management


  • Up to 16 classes of service (CoSs) with the following configurable parameter

    • Service priority level (SPL)

Virtual Trunks

  • Support for up to 32 virtual interfaces per card, each with 16 CoS queues

  • VPI/VCI used to identify virtual connection

  • Virtual interface parameters:

    • Physical port (trunk or UNI)

    • Peak service rate (PSR)

    • Maximum service rate

    • Maximum resource allocation

Cell Buffering

  • Large ingress and egress cell buffer architecture

  • 128,000 cells stored per card

    • Accommodate large traffic bursts

    • Avoid network congestion and cell discard

    • Suited to TCP/IP traffic

Intelligent Quality-of-Service Management Suite

Advanced CoS Management

  • Up to 16 CoS queues, with independent service algorithms dedicated to each interface in the network

Optimized Bandwidth Management

  • Dedicated queue- and rate-controlled servers for each VCC/VPC

  • Dynamic bandwidth management, providing more than 95-percent utilization

Network Management

  • Management using Cisco WAN Manager Software 10.4.10 supports software release 1.1.40 only when deployed with 1.1.34 features.

  • CiscoView for equipment management

  • Simple Network Management Protocol (SNMP) based for configuration and statistics collection

  • Graphical user interface

Physical Specifications

  • Dimensions: (H x D) 15.83 x 15.65 in.

Electrical Specifications

  • Input power required: -48 VDC

  • Power consumption: 100W

Electrical and Safety Standards Compliance

  • EMI/ESD compliance

    • FCC Part 15

    • Bellcore GR1089-CORE

    • IEC 801-2

    • EN55022

  • Safety compliance

    • EN 60950

    • UL 1950

  • Bellcore NEBS: Level 3 compliant

  • Optical safety: IEC 825-1 (Class 1)