Cisco Optical Services Modules

Cisco 7600 Series 2-Port OC-48c OC-48c/1-port OC-48c DPT OSM

Table Of Contents

Data Sheet

Transport Flexibility and Evolution

Ring-Bandwidth Multiplication

Proactive Monitoring and Robust Self-Healing

DPT Features and Benefits

DPT Ring Applications

Feature Summary for Cisco 7600 OC-48 POS/DPT Module

Ordering Information

Technical Specifications

OC-48c/STM-16 POS/DPT Specifications

Gigabit Ethernet Specifications

Cisco 7600 System Performance Features

Physical Specifications

Indicators and Interfaces

Processors and Memory

MIB Support

Environmental Conditions

Regulatory Compliance

Safety Compliance

EMC Compliance

NEBS Level 3 Compliance

ETSI Compliance

Minimum Software Revision

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Data Sheet

Cisco 7600 Series 2-Port OC-48c
OC-48c/1-port OC-48c DPT OSM

OC-48 distribution transport for service provider points of presence (POPs) and central offices with integrated IP services and Gigabit Ethernet

Figure 1

Two-Port OC-48c POS/One-Port OC-48c DPT Optical Services Module

The anticipated dramatic growth of metropolitan-area networks (MANs) is forcing a reevaluation by service providers of the optimal use of their existing transport infrastructure. Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy (SDH) technology will remain a pervasive transport technology because of its well-proven, low-delay restoration and resiliency capabilities. Nevertheless, there is a growing recognition that efficient transport of data traffic in the MAN will require a new class of transport distribution networks. The evolving transport technologies that will support these distribution networks must retain the outstanding resiliency and restoration capabilities of SONET, while delivering improved bandwidth multiplexing capabilities that can be delivered only by a packet-based transport. One of the most promising of these new transport technologies is Cisco Dynamic Packet Transport (DPT), which is based on the emerging resilient packet ring (RPR) IEEE standard.

To meet these requirements, Cisco Systems offers a new Optical Services Module (OSM) for the Cisco 7600 Series Routers and Catalyst 6500 Series Switches that is configurable via software to be used either as a two-port OC-48c/STM-16 Packet-over-SONET (POS) module, or as a one-port OC-48c/STM-16 DPT module. The ability to configure this module for use in either POS networks or DPT networks provides the flexibility that service providers will need to adapt their distribution network to the rapidly increasing data traffic of their end customers. In addition, this module also provides four Gigabit Ethernet interfaces to provide additional data connectivity within the carrier's central office. This new Cisco 7600 Series Optical Service Module enables service providers to scale WAN bandwidth and performance to OC-48 speeds, while offering the flexibility to adapt to the distribution network architecture that will deliver the wide range of Layer 2 and Layer 3 services that their customers are demanding (refer to Figure 1).

The Cisco 7600 is a high-performance router, which evolves from a specific set of Cisco Catalyst® 6500 Series foundation elements combined with new optical-speed WAN modules, and is specifically intended for service provider networks. The Cisco 7600 Series route-processing and forwarding capabilities support the ability to route using such core protocols as Border Gateway Protocol 4 (BGP4), Intermediate System-to-Intermediate System (IS-IS), and Open Shortest Path First (OSPF), while supporting quality of service (QoS) and packet filtering with optical transmission speed performance. Each Cisco 7600 Series chassis provides Network Equipment Building Standards (NEBS)-3 compliance and supports a 256-Gbps switch fabric, enabling high aggregate throughput. The Cisco 7600 Series can be configured with Optical Services Modules and any combination of traditional Cisco Catalyst 6000 Series interfaces, providing for outstanding scalability, with WAN interfaces from DS0 through OC-48/STM-16 and LAN interfaces from 10-Mbps Ethernet to Gigabit Ethernet, and on up to 10 Gigabit Ethernet.

Transport Flexibility and Evolution

Cisco DPT rings run over a variety of transport technologies, including SONET/SDH, wavelength-division multiplexing (WDM), and dark fiber. DPT provides service providers with the flexibility to operate packet rings over their embedded fiber transport infrastructure, as well as providing an evolution path to packet-optimized transport for high-bandwidth IP networks. An OC-48c/STM-16c DPT interface node consists of two OC-48c/STM-16c SONET/SDH interfaces, which have been configured to perform as a single DPT interface.

Ring-Bandwidth Multiplication

DPT uses optimal path selection, spatial reuse, statistical multiplexing, and two active connections to maximize the carrying capacity of the DPT ring. DPT also uses the Spatial Reuse Protocol (SRP) fairness algorithm to ensure that both global fairness and local bandwidth optimization are delivered on all segments of the DPT ring. Finally, DPT configurations are based on the concept of dual counter-rotating rings, which allow for efficient transmission of data and control information.

Proactive Monitoring and Robust Self-Healing

DPT combines powerful SONET/SDH overhead processing with Layer 2 management capabilities to deliver proactive, multilayer performance-monitoring, fault-detection, and fault-isolation capabilities. DPT provides sophisticated protection-switching capabilities for responsive self-healing via the Intelligent Protection Switching (IPS) algorithm. IPS enables sub-50-ms protection-switching performance for rapid service restoration and protection hierarchy to handle cases of multiple, concurrent degrade, failure, or maintenance events.

DPT Features and Benefits

The features and benefits of DPT are described in Table 1.

Table 1  DPT Features and Benefits

SRP fairness and spatial reuse

Maximizes ring capacity, cost-effectiveness, and service stability via spatial reuse, statistical multiplexing, and distributed, inter-nodal fairness

IPS and single ring recovery

Maximizes ring robustness via self-healing around ring node or fiber failures and intelligent handling of multiple concurrent trouble events


Provides fast IP service restoration without Layer 3 reconvergence to minimize impact on revenue-producing traffic

Dual working fiber rings

Using interconnected line cards, dual working fiber rings maximize ring robustness and bandwidth capacity

Topology discovery and routing procedures

Minimize configuration requirements, optimize routing decisions for ring bandwidth maximization, and aid in network monitoring and management

Network monitoring and management

Maximize ring robustness and operational efficiency by providing SONET/SDH support, SRP Management Information Base (MIB) support, and Media Access Control (MAC)-layer counters for proactive monitoring and recovery and effective traffic-engineering capabilities

Pass-through mode support

Maximizes ring robustness and bandwidth availability by avoiding ring wraps caused by soft, recoverable failures in router hardware or software

Transport flexibility

Maximizes deployment flexibility by operating via dedicated fiber, WDM wavelength, or as SONET/SDH tributary—thus matching both embedded and evolving infrastructure

Optics options

Maximize application versatility and deployment flexibility by supporting single-mode short-, intermediate-, and long-reach optics

DPT Ring Applications

DPT rings enable a key set of applications for service providers and large enterprises, including:

Robust, high-bandwidth intra-POP connectivity

Regional POP interconnectivity

Cable data access and distribution

Metro packet transport for business and residential access services

Regional backbone rings

Distributed enterprise campus rings

Feature Summary for Cisco 7600 OC-48 POS/DPT Module

Software configurable selection of either OC-48 POS or DPT modes, thereby supporting transition between POS and DPT transport-distribution network architectures

High-performance application of QoS services (when configured for POS operation only), with support for 64 Differentiated Services Code Point (DSCP)-based queues per interface, where each queue is serviceable for IP-based traffic shaping and Class-Based Weighted Fair Queuing (CBWFQ)

Compatibility with either the new Cisco 7600 Series or the Cisco Catalyst 6500 Series chassis (provided the Cisco Catalyst 6500 Series has been appropriately upgraded)

Deep packet buffering to maximize TCP throughput, with advanced traffic management and prioritization schemes to ensure deterministic packet delivery

Four additional Gigabit Ethernet ports, in addition to the OC-48 POS/DPT interface, thereby providing flexibility in WAN and LAN connectivity

Ordering Information

Ordering information for the Cisco 7600 Series One-Port OC-48c/STM-16 POS Optical Services Module is given in Table 2.

Table 2  One-Port OC-48c/STM-16 POS Optical Services Module Ordering Information

Part Number

Two-port OC-48c/STM-16 SONET/SDH configurable to be one-port

OC-48c/STM-16 DPT OSM, SM-SR1 with four Gigabit Ethernet


Two-port OC-48c/STM-16 SONET/SDH configurable to be one-port

OC-48c/STM-16 DPT OSM, SM-SR with four Gigabit Ethernet, spare


Two-port OC-48c/STM-16 SONET/SDH configurable to be one-port

OC-48c/STM-16 DPT OSM, SM-IR2 with four Gigabit Ethernet


Two-port OC-48c/STM-16 SONET/SDH configurable to be one-port

OC-48c/STM-16 DPT OSM, SM-IR with four Gigabit Ethernet, spare


Two-port OC-48c/STM-16 SONET/SDH configurable to be one-port

OC-48c/STM-16 DPT OSM, SM-SL3 with four Gigabit Ethernet


Two-port OC-48c/STM-16 SONET/SDH configurable to be one-port

OC-48c/STM-16 DPT OSM, SM-SL with four Gigabit Ethernet, spare


128-MB ECC4 memory for OSMs


256-MB ECC memory for OSMs

Note: "=" denotes spare (that is, OSM-2OC48/1DPT-SS= is the spare version when OSM is not ordered in a system).

1. Single mode, small reach
2. Single mode, intermediate reach
3. Single mode, long reach
4. Error Correcting Code

Technical Specifications

OC-48c/STM-16 POS/DPT Specifications

SONET/SDH Compliance

Telcordia (Bellcore) GR-253-CORE (as applicable)

ITU-T G.707, G.957, G.958 (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)


Internet Engineering Task Force (IETF) RFC 1661, Point-to-Point Protocol (PPP)

IETF RFC 1662, PPP in HDLC Like Framing

IETF RFC 2615, PPP over SONET/SDH with 1+x43 Self-Synchronous Payload Scrambling

SONET/SDH 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)


Loss of signal (LOS)

Loss of frame (LOF)

Error counts for B1

Threshold crossing alarms (TCA) for B1


Line alarm indication signal (LAIS)

Line remote defect indication (LRDI)

Line remote error indication (LREI)

Error counts for B2

TCA for B2


Path alarm indication signal (PAIS)

Path remote defect indication (PRDI)

Path remote error indication (PREI)

Error Counts for B3

Path unequipped indication signal (PUNEQ)

Path payload mismatch indication (PPLM)

TCA for B3

Loss of pointer (LOP)

New pointer events (NEWPTR)

Positive stuffing event (PSE)

Negative stuffing event (NSE)

SONET/SDH Synchronization

Local (internal) timing (for inter-router connections over dark fiber or WDM equipment)

Loop (line) timing (for connection to SONET/SDH equipment)

+/-20 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


LC connector

Table 3  POS/DPT Optical Services Module Specifications

Fiber interface
Output Power
Input Power
Input Sensitivity Wavelength









-10.0 dBm

-3.0 dBm

0.0 dBm

-18.0 dBm

1266 nm

1360 nm


-5.0 dBm

0.0 dBm

0.0 dBm

-18.0 dBm

1260 nm

1360 nm


-2.0 dBm

+3.0 dBm

-9.0 dBm

-28.0 dBm

1500 nm

1580 nm

1. Single mode, small reach
2. Single mode, intermediate reach
3. Single mode, long reach

Gigabit Ethernet Specifications

IEEE 802.3z compliant

Gigabit interface converter (GBIC)-based Gigabit Ethernet interfaces with SC connectors

Table 4  Gigabit Ethernet Optical Specifications

1000BASE-LX: 50-_m multimode fiber

Up to 550m

1000BASE-LX: 9/10-_m single-mode fiber

Up to 5 km

1000BASE-LH: 62.5-_m multimode fiber

Up to 550m

1000BASE-LH: 50-_m multimode fiber

Up to 550m

1000BASE-LH: 9/10-_m single-mode fiber

Up to 10 km

1000BASE-ZX: 9/10-_m single-mode fiber

Up to 70 km

1000BASE-ZX: dispersion-shifted fiber

Up to 100 km

Support for IEEE 802.1Q virtual LAN (VLAN) trunking with up to 4000 simultaneous VLANs

Support for Hot Standby Router Protocol (HSRP)

IEEE 802.3x support for autonegotiation flow control

Support for jumbo frames with a maximum transmission unit (MTU) of 9192 bytes

Cisco 7600 System Performance Features

Hardware-based Cisco Express Forwarding at no less than 30 million Mpps

Access control list (ACL) application, with as many as 15,000 ACL rules, at no less than 30 Mpps

QoS classification at no less than 30 Mpps

Policy routing at no less than 30 Mpps

Support for 128,000 traffic accounting entries per system

Support for online insertion and removal (OIR)

Support for at least 220 ms of packet buffering per port

Support for Simple Network Management Protocol (SNMP) I and II and four Remote Monitoring (RMON) groups per port: statistics, history, alarms, and events

Physical Specifications

Occupies one slot in any Cisco 7600 NEBS-certified chassis

Occupies one slot in any Cisco Catalyst 6500 Series chassis (with appropriate upgrades)

Two OC-48c/STM-16 ports supported per OSM

Four Gigabit Ethernet optical ports per OSM

Support for up to seven two-port OC-48c/STM-16 OSMs in a nine-slot Cisco 7600 Series chassis

Required with either the Cisco 7600 Series or Cisco Catalyst 6500 Series chassis:

Supervisor Engine II: WS-X6K-S2-MSFC2

Recommended with either the Cisco 7600 Series or Cisco Catalyst 6500 Series chassis:

Switch fabric module—256-Gbps crossbar fabric: WS-C6500-SFM

Dimensions (H x W x D): 1.2 x 14.4 x 16 in. (3.0 x 35.6 x 40.6 cm)

Weight: 11.1 lb or 5.0 kg

Mean time between failure (MTBF): seven years for system configuration

Power consumption: 220W at 4.25 amps

Indicators and Interfaces

Status: green (operational)/red (faulty)/orange (module booting or running diagnostics)

Link good: green (port active)/orange (disabled)/off (not active/connected)/blinking orange (failed diagnostic and disabled)

Processors and Memory

One 225-MHz R7000 MIPS RISC processor

Configurable packet/route table memory options per line card:


128-MB ECC SDRAM (default)


Parallel Express Forwarding (PXF) IP services processor(s)

Provides up to 6 Mpps of distributed IP service application per PXF IP services processor

Nonconfigurable PXF memory per line card:

128-MB ECC SDRAM of route table memory per PXF IP services processor

4-MB SSRAM of packet processing memory per PXF IP services processor

MIB Support



RFC 1901 through 1907 SNMP v2c


IF-MIB (RFC 1573)








IP Statistics MIB


Committed Access Rate (CAR) MIB

Weighted Random Early Detection (WRED) MIB

Resource Reservation Protocol (RSVP) MIB

Cisco Round Trip Time Monitor (RTTMON) MIB

Environmental Conditions

Operating temperature: 32° to 104°F (0° to 40°C)

Storage temperature: -4° to 149°F (-20° to 65°C)

Relative humidity: 5 to 90%, noncondensing

Operating altitude: -500 to 6500 ft

Regulatory Compliance

Safety Compliance

UL 1950

CAN/CSA C22.2 No.950-95

EN 60825-1 Laser Safety (Class 1)

21CFR1040 Laser Safety


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


CE Marking

NEBS Level 3 Compliance

The Cisco 7600 chassis and Cisco Catalyst 6509 chassis have been certified as NEBS Level 3 compliant, according to the following specifications:

GR-63-CORE - NEBS: Physical protection

GR-1089-CORE - NEBS: EMC and safety

ETSI Compliance

ETS-300386-2 switching equipment

Minimum Software Revision

Cisco IOS® Software Release 12.1(12)E

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