Cisco 7300 Series Routers

Cisco 7300 Six-Port Clear Channel T3 (DS3) Linecard

Data Sheet

Six-Port Clear Channel T3 (DS3)
Line Card for the Cisco 7300 Internet Router

The Six-port T3 Line Card provides the interface density necessary for cost-effective deployment of the Cisco 7300 as a network edge aggregation router in tier 2 and 3 service provider POPs. The ability to deploy 6 T3 connections in a single interface slot allows efficient use of service provider rack space by aggregating up to 24 T3s in only 4 rack-units of space.

Figure 1
6-Port Clear Channel T3 (DS3) Line Card

Developed for customers needing a combination of performance and deployment flexibility, the Cisco 7300 is the embodiment of both present day and future requirements for a Mid-Range router. The Cisco 7300 delivers high-Performance forwarding and hardware accelerated services in a compact four rack-unit (4RU), four interface slot form factor.

Powerful and flexible, the Cisco 7300 provides multiprotocol support, interface granularity, and high-availability features to create a platform that is ideal for deployment in various applications such as high-end enterprise routing, medium speed and density leased-line aggregation in service provider tier 2 and tier 3 PoPs, and service provider-managed customer premise equipment (CPE) deployments. Providing WAN connectivity at speeds ranging from DS3 through OC48/STM-16, and LAN connectivity at speeds up to Gigabit Ethernet (via two 10/100/1000 Ethernet ports built into the NSE-100 route processor), the Cisco 7300 supports a wide range of concurrently running applications and lives up to the high standards of Cisco's 7000 series of Mid-Range routers.

Features and Benefits Overview

Table 1:
Features Benefits
6 ports of T3 per line card

Maximizes connectivity within the rack space

Up to 45 Mbps per port

Provides high-performance routing and connectivity

Online insertion and removal (OIR)

Allows for insertion of the card without rebooting the router

Integrated data service unit (DSU)

No need for extra equipment

Product Specifications: Components

Line Card

  • Full-duplex synchronous serial DS3 interface

  • Meets ANSI T1.404a recommendations

  • Online insertion and removal (OIR)

  • Integrated DSU functionality

  • Support for 16- and 32-bit cyclic redundancy checks (CRCs)

  • Support for Frame Relay, High-Level Data Link Control (HDLC), and Point-to-Point Protocol (PPP) serial encapsulations

  • Support for remote and local loopbacks

  • Subrate DS3 support for Cisco, Kentrox, Larscom, and Digital Link formats along with the associated scrambling, in some modes, scrambling is optional.

  • Clear-channel DS3 (framed but unchannelized)

  • M23 and C-bit-parity DS3 frame formats

  • Detection and counting of RAI, parity errors, FEBE, framing errors, LOF, LOS (no counters), IDLE (no counters)

  • One-second performance monitoring counters for ES, SES

  • Generates AIS, RAI, and FEAC

  • Generates F-, X-, P-, and M-bit errors; LCVs; all zeros; RAI; and FEBE for testing

  • Line, payload, and diagnostic loopbacks

  • Drives up to 900 feet of 75-ohm coaxial cable 450 feet to DSX-3 demarcation point (DSX)

  • 75-ohm SMB-type coaxial connections

  • B3ZS line coding
    Table 2: Feature Compatibilities of 6 T3 Line Card DSUs
    DSU Full Rate Support Scrambling Support Subrate Support MDL1 Support















    1MDL (Maintenance Digital Link)
    2The 6 port T3 line card supports scrambling and Kentrox subrate at the same time.

Product Specifications: Cards, Ports, Slots

Rack Density

Six-port T3 for Cisco 7300 chassis and rack density1

Table 3:
6-Port T3 Line Card Cisco 7304 Chassis Density Cisco 7304 Rack Density

24 T3 and 2 GE ports

264 T3 and 22 GE ports

  • Up to four 7300-6T3 modules supported in a 4-slot chassis

  • 6 clear channel T3s supported per line card

Product Specifications: Environmental Conditions

Table 4:
6-Port Clear Channel T3
Operating temperature

32 to 104° F

(0 to 40° C)

Storage temperature

-4 to 149° F

(-20 to 65° C)

Operating humidity

5 to 90% (noncondensing)


-500 to 6,500 ft

Product Specifications: Performance

  • Six-ports of T3 at 45 Mbs full duplex

Product Specifications: MIBs

  • DS3 interface MIB (RFC 1407)

  • See NSE-100 data sheet for more MIB support

Product Specifications: Physical Specifications

Table 5:
6-Port T3

1.92 in. (4.87 cm)


8.44 in. (21.43 cm)


12.94 in. (32.87 cm)


3.0 lb (1.36kg)

Mean Time Between Failure (MTBF)

5.5 year for system configuration

Product Specifications: Line Card Indicators

Table 6:
LED Label Color State Function



Line card is ready to be removed


Line card is online




Indicates line card is online


Indicates line card bootstrapping is in progress


Indicates line card is offline or deactivated




Line card port is enabled


Line card port is in loopback mode or is receiving or transmitting alarms


Line card port is disabled

Regulatory Compliance and Safety Information

Product Regulatory Compliance

  • Products bear CE marking indicating compliance with the 89/366/EEC and 73/23/ECC directives, which include the following safety and EMC standards.


  • UL 1950

  • CSA C22.2 No. 950

  • EN60950

  • IEC 60950

  • TS 001

  • AS/NZS 3260


  • FCC Part 15 (CFR 47) Class A

  • ICES-003 Class A

  • EN55022 Class A

  • CISPR 22 Class A

  • AS/NZS 3548 Class A

  • VCCI Class A

  • EN55024

  • EN50082-1

  • EN300386

Industry EMC, Safety and Environmental Standards

  • GE-63-Core NEBS Level 3 Requirement

  • GR-1089-Core NEBS Level 3 Requirement

  • ETS 300-019 Storage Class 1.1

  • ETS 300-019 Transportation Class 2.3

  • ETS 300-019 Stationary Use Class 3.1

Product Ordering Details: Ordering Instructions

Please visit to place an order.

Product Ordering Details: Product Part Number

Table 7:
Product Number Product Description

6-Port Clear Channel T3 Card, Cisco 7300 Line Card


6-Port Clear Channel T3 Card, Cisco 7300 Line Card Spare

Service and Support

Cisco Systems offers a wide range of service and support options for its customers. More information on Cisco service and support programs and benefits can be found at

1Configured with:
1 NSE-100 per Cisco 7300 chassis
4 x 6-port T3 Line Cards per Cisco 7300 chassis
11 Cisco 7300 chassis per 7' rack