Cisco 7600 Series Routers

Cisco 7600 Series 1-port Channelized OC-12/STM-4 to DS3/E3 OSM

Data Sheet

Cisco 7600 Series 1-Port Channelized OC-12/STM4 to DS3/E3 OSM

Figure 1
One-Port CHOC12/STM4 Optical Services Module

DS3/E3, OC3c/STM1 Aggregation for Large Enterprise Head Offices

Enterprise customers are continuing to see WAN usage increase as Internet and intranet usage grows. Bandwidth demand is driven by applications such as VoIP, videoconferencing, and large file transfers. As the connectivity needs of remote sites scale from nxDS1/E1 to DS3/E3, there is increasing urgency to find a scalable high-speed leased line aggregation solution at the head office. Cisco Systems has responded by developing a channelized OC12/STM4 card that supports DS3, E3 as well as subrate DS3 and OC3c/STM1 on the Cisco 7600 Series Routers and Cisco Catalyst 6500 Series Switches.

The card is ideal for Enterprise customers with multiple high-speed circuits connecting remote sites served by local Telcos and PTTs. It's also ideal for customers considering bandwidth expansion of existing leased line networks. Vertical industries that benefit most include financial institutions, healthcare systems, government agencies, school districts and universities, as well as other geographically dispersed organizations.

The new, enhanced CHOC12/STM4 card is designed to simplify the deployment of DS3/E3 and OC3c/STM1 services by providing up to 12 DS3/E3 channels over a single optical interface. In SONET mode, the card can be configured to support any combination of DS3/E3, subrate DS3, and OC3c. In SDH mode, the card can support E3/DS3 and STM1s. The card also comes with four Gigabit Ethernet interfaces that enable additional connectivity into server farms or service provider networks.

Enhanced OSM functionality includes support for future software enhancements to deliver either Layer-2 or Layer-3 network aggregation services deployed over a consolidated network architecture based on either IP or MPLS protocols. This design expands support for Layer-2 services based on protocols such as Frame Relay, Ethernet and ATM, while simultaneously supporting Layer-3 services, such as Internet Access or IETF RFC 2547 VPN's.

CHOC12/STM4 to DS3/E3 provides the following benefits:

  • Cost reduction—Eliminates expensive cables, DS3 equipment, and in some cases Frame Relay switching gear.
  • Simplifies DS3/E3 deployment—A single optical fiber replaces a complex maze of cables and equipment.
  • Easier management—With the reduction in equipment, DS3/E3 deployment is more efficient.
  • Improved network availability and reliability—The card supports APS/MSP, thus providing additional protection in the event of a card failure.
  • Investment protection—The CHOC12/DS3 is compatible with leading DS3 DSU/CSUs.
  • Reduces power consumptionBy aggregating functionality onto a single line card, less power is consumed per DS3/E3.
  • Saves rackspaceone line card consumes a smaller footprint than 12 port adapters in Cisco 7500 Series routers.


The one-port CHOC12/T3 transmits IP packets directly over SONET/SDH-based optical interfaces at line rate. The card enables the Cisco 7600 to transmit and receive DS3/E3-based IP packets across standard SONET/SDH transmission equipment without the need for additional equipment. The card allows an SP or enterprise network designer to attach the Cisco 7600 directly to an Add Drop Multiplexers (ADMs). IP packet data is encapsulated with Point-to-Point Protocol (PPP), High-Level Data Link Control (HDLC), or Frame Relay protocol. Based on the routing information contained in the IP packet, the line card routes the IP packet to 1 of 12 virtual DS3 ports (or OC3c, etc). The IP packets are then placed into DS3 frames, and the DS3 frames are mapped into the appropriate SONET/SDH payload envelope.

The Cisco 7600 is a high-performance router based on the Cisco Catalyst 6500 Series and the Cisco 7500 Series router. This solid foundation, combined with high-speed WAN modules, make the Cisco 7600 well suited for service provider networks. Each Cisco 7600 provides a NEBS-3 compliant chassis. The Cisco 7600 route processing and forwarding can be fully redundant. The platform supports such core routing protocols as Border Gateway Protocol 4 (BGP4), Intermediate System (IS-IS), and Open Shortest Path First (OSPF). Moreover, the Cisco 7600 provides a wide range of IP services, traffic shaping, and packet filtering. The Cisco 7600 includes an optional 256-Gbps switch fabric that enables high aggregate throughput. The Cisco 7600 can be configured with optical services modules (OSM) and any combination of traditional Cisco Catalyst 6000 Series interfaces, including the FlexWAN module, which enables the use of many WAN port adapters from the Cisco 7500 and Cisco 7200. In summary, the Cisco 7600 provides connectivity from DS0 through OC48/STM16 in addition to LAN interfaces from 10-Mbps Ethernet to Gigabit Ethernet.

Figure 2

Feature Summary

  • Parallel eXpress Forwarding (PXF) IP Services Processor on the line card. The PXF IP Services Processor consists of a 4 x 4 array of microprocessing units, each equipped with local memory, to deliver a pipelined, parallelized processing array. Each PXF IP Services Processor can apply IP services to 16 different packets simultaneously—all with high levels of performance. The OC12 line card is populated with two PXF IP Services processors.
  • High performance forwarding of distributed IP service.
  • Programmable software feature sets for "evergreen" IP service delivery. Unlike traditional ASICs, which have feature sets hardcoded in silicon, each PXF engine can be enhanced in the field via easy software upgrade.
  • Deep packet buffering to maximize TCP throughput, with advanced traffic management and prioritization schemes to ensure deterministic packet delivery.
  • Programmable software feature sets employing software programmable ASICs for feature enhancements.
  • Four additional ports of Gigabit Ethernet, provides connectivity to other routers or servers without burning up "customer facing" slots.
  • Compatibility with either the new Cisco 7600 or the Cisco Catalyst 6500 chassis (provided that the Cisco Catalyst 6500 has been appropriately upgraded).

Enhanced Features Include

  • Queue management memory is now 256MB per PXF network processor to support enhanced QoS and traffic shaping queues. Supporting a minimum of 8000 unidirectional QoS queues per PXF network processor, as well as improving the traffic shaping and QoS capabilities.
  • 1000 VRFs per interface card (500 VRFs if any non-enhanced modules in chassis)
  • WRED support
  • Future support for hierarchical QoS for Frame Relay and Ethernet encapsulations

Ordering Information

Table 1   One-Port CHOC12 Optical Services Module Ordering Information

Part Number Description


One-Port Singlemode Intermediate Reach (LC) OC12 to T3 with 4 Gigabit Ethernet


128-MB ECC Memory for Optical Services Modules


256-MB ECC Memory for Optical Services Modules


512-MB ECC Memory for Optical Services Modules

Note:    "=" denotes a spare order (for example OSM-1OC12/T3-SI= is the spare order number when the OSM is not ordered in a system).

Technical Specifications

SONET Compliance

  • Telecordia (Bellcore) GR-253-CORE (as applicable)
  • ITU-T G.707, G.957, G825 (as applicable)
  • Support for 1+1 SONET Automatic Protection Switching (APS) as per GR-253-CORE—per port, per line card, per chassis (as applicable)
  • Support for 1+1 SDH Multiplex Section Protection (MSP) as per G.783 Annex A—per port, per line card, per chassis (as applicable)

SONET Errors, Alarms, and Performance Monitoring

  • Signal Failure Bit Error Rate (SF-ber)
  • Signal Degrade Bit Error Rate (SD-ber)
  • Signal Label Payload Construction (C2)
  • Path Trace Byte (J1)
  • Section:
    • Loss of Signal (LOS)
    • Loss of Frame (LOF)
    • Error Counts for B1
    • Threshold Crossing Alarms (TCA) for B1
  • Line:
    • Line Alarm Indication Signal (LAIS)
    • Line Remote Defect Indication (LRDI)
    • Line Remote Error Indication (LREI)
    • Error Counts for B2
    • Threshold Crossing Alarms (TCA) for B2
  • Path:
    • Path Alarm Indication Signal (PAIS)
    • Path Remote Defect Indication (PRDI)
    • Path Remote Error Indication (PREI)
    • Error Counts for B3
    • Threshold Crossing Alarms (TCA) for B3
    • Loss of Pointer (LOP)
    • New Pointer Events (NEWPTR)
    • Positive Stuffing Event (PSE)
    • Negative Stuffing Event (NSE)
    • Path Unequipped Indication Signal (PUNEQ)
    • Path Payload Label Mismatch (PPLM)

SONET Synchronization

  • Local (Internal) Timing (for inter-router connections over dark fiber or WDM equipment)
  • Loop (Line) Timing (for connection to SONET/SDH equipment)
  • +/- 4.6 ppm Clock Accuracy over Full Operating Temperature

Network Management

  • Local Loopback
  • Network Loopback
  • NetFlow Data Export
  • RFC 1595, Performance Statistics for Timed Intervals (Current, 15 minute, multiple 15 minute, and 1 day intervals)
    • Regenerator Section
    • Multiplex Section
    • Path Errored Seconds
    • Severely Errored Seconds
    • Severely Errored Framed Seconds

DS3 Specifications

  • Full- and half-duplex connectivity at DS3 rate (44.736 MHz)
  • Scrambling and subrate support of major DSU vendors: Kentrox, Digital Link, Larscom, Verilink, and Adtran
  • C-Bit or M23 framing (software configurable)
  • 16- and 32-bit cycles redundancy check (CRC) supported. (16-bit default)
  • DS3 FEAC channel support
  • 24-hour history maintained for error statistics and failure counts
  • Support for loopback (internal, line and remote [remote only with C-bit framing])
  • DS3 alarm/event detection (once per second polling)
    • AIS: alarm indication signal
    • OOF: out of frame
    • FERF: far-end receive failure

E3 Specifications

  • Full duplex operation at E3 rate (34.368 MHz)
  • Mapping via AU-3 or AU-4
  • Line and local loopback support
  • G.751 framing
  • 16- and 32-bit cycles redundancy check (CRC) supported. (16-bit CRC default)
  • Software-setable E3 national service bits
  • 24-hour history maintained for error statistics and failure counts

E3 alarm/event detection (once per second polling)

  • RCLK: receive clock signal
  • AIS: alarm indication signal
  • OOF: out of frame state
  • FERF: far-end receive failure

· DS3/E3/POS Encapsulations

  • HDLC: High-Level Data Link Control
  • PPP: Point-to-Point Protocol
  • Frame Relay Protocol

    Table 2   Optical Specifications

    Fiber Interface Output Power Input Power   Wavelength
      Min Max Min Max Min Max

    SI (LC- Connectors)

    -15.0 dBm

    -8.0 dBm

    -28.0 dBm

    -8.0 dBm

    1270 nm

    1380 nm

Gigabit Ethernet Specifications

  • IEEE 802.3z compliant
  • GBIC-based Gigabit Ethernet Interfaces with SC connectors:

    Table 3   Gigabit Ethernet Optical Specifications

    GBIC Distance

    1000BaseLX: 50 um multimode fiber

    Up to 550 m

    1000BaseLX: 9/10 um single-mode fiber

    Up to 5 km

    1000BaseLH: 62.5 um multimode fiber

    Up to 550 m

    1000BaseLH: 50 um multimode fiber

    Up to 550 m

    1000BaseLH: 9/10 um single-mode fiber

    Up to 10 km

    1000BaseZX: 9/10 um single-mode fiber

    Up to 70 km

    1000BaseZX: dispersion-shifted fiber

    Up to 100 km

  • Support for IEEE 802.1Q VLAN Trunking
  • Support for Hot Standby Routing Protocol (HSRP)
  • IEEE 802.3x support for auto-negotiation flow control
  • Support for Jumbo frames with an MTU of 9216 bytes

Physical Specifications

  • Occupies one slot in any Cisco 7600 chassis
  • Occupies one slot in any Cisco Catalyst 6500 chassis
  • One OC12/STM4 ports supported per optical service module
  • Four Gigabit Ethernet optical ports per optical service module
  • Up to eight optical service modules supported in a nine-slot chassis
  • Required with either the Cisco 7600 or Cisco Catalyst 6500 chassis:
    • Supervisor Engine 2: WS-X6K-S2-MSFC2
  • Recommended with either the Cisco 7600 or Cisco Catalyst 6500 chassis:

Switch Fabric Module—256 Gbps Crossbar Fabric:

    • WS-C6500-SFM
    • 2500W power supply
  • Dimensions (H x W x D): 1.2 x 14.4 x 16 in. (3.0 x 35.6 x 40.6 cm)
  • Weight: 10.8 lb (4.9 kg)

Table 4   Line Card Power Requirements

Number and Speed of Interface Power Requirement

1 Port CHOC12/STM4


Indicators and Interfaces

  • Four LEDs per port:
    • Port Active: Green—when port is enabled and active; Off when port is not enabled
    • Carrier/Alarm: Green if valid SONET/SDH frame and no alarms; Yellow if valid SONET/SDH frame with alarms; Off if no SONET/SDH signal
    • Tx Activity: Blinks Green if port is transmitting data; Off when no data is transmitting
    • Rx Activity: Blinks Green if port is receiving data; Off when no data is received

Processors and Memory

  • One 262 MHz RM7000 MIPS RISC processor for line card control and management
  • Configurable processor/route table memory options:
    • 64-MB ECC SDRAM (default)
    • 128-MB ECC SDRAM
    • 256-MB ECC SDRAM
    • 512-MB ECC SDRAM
  • Two PXF IP services processors
  • Provides up to 6 Mpps of distributed IP service application per PXF IP Services Processor
  • Nonconfigurable PXF memory per line card:
    • 128-MB SDRAM of route table memory per PXF IP Services Processor
    • 256-MB SDRAM of packet buffer memory per PXF IP Services Processor (CRC Checks per Packet)
    • 4-MB SDRAM of packet processing memory per PXF IP Services Processor

Environmental Conditions

  • Operating temperature: 32 to 104° F (0 to 40° C)
  • Storage temperature: -4 to 149° F (-20 to 65° sC)
  • Relative humidity: 5 to 90%, noncondensing
  • Operating altitude: -500 to 6,500 ft

Regulatory Compliance

Safety Compliance

  • UL 60950
  • CAN/CSA C22.2 No.60950
  • 21CFR1040 Laser Safety
  • EN60950
  • IEC 60950
  • TS 001
  • AS/NZS 3260

EMC Compliance

  • FCC Part 15 (CFR 47) Class A
  • VCCI Class A
  • EN55022 Class A
  • CISPR 22 Class A
  • AS/NZS 3548 Class A
  • EN55024
  • EN50082-1
  • ICEA 003 Class A
  • CE Marking

ETSI Compliance

  • ETS-300386-2 Switching Equipment

Minimum Software Revision

Cisco IOS® Software Release 12.1(12)E—see for the most accurate release information.