Cisco Shared Port Adapters SPA Interface Processors

Cisco 2- and 4-Port Clear Channel T3/E3 Shared Port Adapters Version 2 Data Sheet

  • Viewing Options

  • PDF (425.0 KB)
  • Feedback

Demand for high-capacity corporate backbones, for high-speed access to the global Internet, and for trunking connections for service provider internetworking have led to growth in clear channel T3/E3 connections that has outpaced all other types and speeds of leased lines. This growth places tremendous strain on service providers and network managers who must provision and manage new T3/E3 connections. The Cisco® Clear Channel T3/E3 Shared Port Adapters (SPAs) Version 2 for the Cisco 7600 and Cisco ASR 1000 and ASR 9000 Series Aggregation Services Routers offer high-density, highly manageable T3/E3 line connectivity and termination. With integrated line-interface data service units (DSUs) that allow T3/E3 lines to be directly terminated on a Cisco router, the Cisco Clear Channel T3/E3 SPAs Version 2 simplify T3/E3 line management, reduce provisioning costs, and make valuable rack space available.

The Cisco Interface Flexibility (I-Flex) approach combines SPAs and SPA interface processors (SIPs), providing an extensible design that enables service prioritization for data, voice, and video services. Enterprise and service provider customers can take advantage of improved slot economics resulting from modular port adapters that are interchangeable across Cisco routing platforms. The Cisco I-Flex design maximizes connectivity options and offers superior service intelligence through programmable interface processors that deliver line-rate performance. I-Flex enhances speed-to-service revenue and provides a rich set of quality-of-service (QoS) features for premium service delivery while effectively reducing the overall cost of ownership. This data sheet contains the specifications for the Cisco 2- and 4-Port Clear Channel T3/E3 SPAs Version 2 (Figure 1).

Figure 1.     Cisco 4- and 2-Port Clear Channel T3/E3 SPAs Version 2

Product Overview

The Cisco Clear Channel T3/E3 SPAs Version 2 are designed to provide direct connectivity to T3/E3 lines for full-duplex communications at the T3 rate of 44.736 MHz or E3 rate of 34.368 MHz. They are available in 2- and 4-port options. The ports are configurable as either all T3 or all E3. To support the widest range of operational environments and to offer the greatest flexibility in provisioning clear channel T3/E3 connections, the Cisco Clear Channel T3/E3 SPAs Version 2 take a groundbreaking step and bring together proprietary subrate and scrambling features of T3/E3 DSU vendors Quick Eagle Networks (formerly Digital Link), Larscom, ADC Kentrox, Adtran, and Verilink. Subrate support in the Cisco Clear Channel T3/E3 SPAs Version 2 maximizes the application of these products in service provider environments for tiered T3 services. By simultaneously supporting interoperability with a wide range of third-party DSU vendors, the Cisco Clear Channel T3/E3 SPAs Version 2 offer the flexibility to support installed equipment without committing customers to a proprietary solution.

The Cisco Clear Channel T3/E3 SPAs Version 2 are hot-swappable and support service-transparent online insertion and removal (OIR), allowing removal of the SPA without affecting the interface processor and other SPAs.


The Cisco Clear Channel T3/E3 SPAs Version 2 can be used to provide direct customer access or network-to-network connections. In some cases, T3/E3 offers the only high-speed service to remote points of presence (POPs) or customer installations that cannot obtain optical channelized service.

The Cisco Clear Channel T3/E3 SPAs Version 2 support three different Layer 2 encapsulations of packets:

   Point-to-Point Protocol (PPP)

   High-Level Data Link Control (HDLC)

   Frame Relay

By supporting these three encapsulations, the Cisco Clear Channel T3/E3 SPAs Version 2 enable the Cisco 7600 and Cisco ASR 1000 and ASR 9000 Series Routers to offer high-speed, IP-based direct access or IP-over-Frame Relay deployments (Figure 2).

Figure 2.     IP-Based Direct Access or IP-over-Frame Relay Deployments

Features and Benefits

The Cisco Clear Channel T3/E3 SPAs Version 2 offer many advantages, including:

   2- and 4-port clear channel T3 or E3 options

   Integrated DSU functions

   Interoperability with all Cisco T3/E3-capable products and products from other leading T3/E3 DSU and Frame Relay equipment vendors

   Full-duplex, full-rate, and subrate support

The Cisco SPA/SIP portfolio offers the following additional advantages:

   Highly modular, flexible, intelligent interface processors

     Superior flexibility, supporting a combination of interface types on the same interface processor for consistent services, independent of access technology

     Pioneering programmable interface processors that provide flexibility for the service diversity required in next-generation networks

     Innovative design that supports intelligent service delivery without compromising on performance

   Increased speed-to-service revenue

     The scalable, programmable Cisco architecture extended to 10 Gbps dramatically improves customer density, increasing potential revenue per platform.

     Interface breadth (copper, channelized, Packet over SONET/SDH [PoS], ATM, and Ethernet) on a modular interface processor allows service providers to roll out new services more quickly, helping ensure that all customers receive consistent, secure, and guaranteed services.

     High-density Small Form-Factor Pluggable (SFP) interfaces are featured for high-port-count applications with reach flexibility. Future optical technology improvements can be adopted using existing SPAs.

   Dramatically improved financials of your routing purchase

     Improved slot economics and increased density reduce capital expenditures (CapEx).

     The ability to easily add new interfaces as they are needed enables a "pay-as-you-grow" business model.

     SPAs are shared across multiple platforms, and can be easily moved from one to another, providing consistent feature support, accelerated product delivery, and a significant reduction in operating expenses (OpEx) through common sparing as service needs change.

Product Specifications

Table 1 gives specifications of the Cisco Clear Channel T3/E3 SPAs Version 2.

Table 1.       Product Specifications



Product compatibility

  Cisco 7600 Series Routers
  Cisco ASR 1000 Series Routers
  Cisco ASR 9000 Series Routers

Minimum software version

  Cisco 7600 Series Routers with Cisco IOS® Software Release 15.4(2)S and Cisco IOS XE Software Release
  Cisco ASR 1000 Series Routers with Cisco IOS XE Software Releases 3.12.0,3.11.2, and 3.10.3
  Cisco ASR 9000 Series Routers with Cisco IOS XR Software Release 5.2.0

Port density per SPA

2- and 4-port options

Physical Interface

  1.0 and 2.3 RF connectors (75-ohm impedance)
  1.0 and 2.3 R-to-BNC adapter cable options


Serial encapsulations:

  PPP, RFC 1662
  Frame Relay, RFC 1490

Features and functions

  Up to 4 independent T3 or E3 ports configurable as either all T3 or all E3 only
  Full-duplex connectivity at T3 rate (44.736 MHz) or E3 rate (34.368 MHz)
  Subrate and scrambling support of Quick Eagle Networks (formerly Digital Link), Larscom, ADC Kentrox, Adtran, and Verilink DSUs
  Internal or network clock selectable per channel
  Line and payload loopback capabilities:
   Local and remote loopback at the T3 level
   Response to embedded loopback commands
   Insertion of loopback commands into transmitted signal
  Bit-error-rate-testing (BERT) pattern generation and detection per channel
   Selectable pseudorandom pattern up to 32 bits long, including all 0s, all 1s, 215, 220, 220 Quasi-Random Signal Sequence (QRSS), 223, and alternating 0s and 1s
   32-bit error-count and bit-count registers
   Fully independent transmit and receive sections
   Detection of test patterns with bit error rates up to 10-2
  24-hour history maintained for error statistics and failure counts, at 15-minute intervals
  16- and 32-bit cyclic redundancy check (CRC); 16-bit default

T3-specific features

  C-bit or M23 framing
  Binary 3-zero substitution (B3ZS) line coding
  T3 far-end alarm and control (FEAC) channel support
  Compliance with T3 pulse mask per ANSI T1.102-1993
  Maintenance data link (MDL)
  Line build-out up to 450 feet (135 meters)
  Alarm monitoring
   Alarm indication signal (AIS)
   Loss of signal (LOS)
   Out of frame (OOF)
   Far-end receive failure (FERF)
  Performance data collection
   Line coding violation (LCV)
   Framing bit errors (F- or M-bit errors)
   P-bit error counts
   C-bit error counts
   Far-end block error (FEBE) counts

E3-specific features

  G.751, or G.832 and unframed G.703 framing
  High-density bipolar with three zeroes (HDB3) line coding
  Compliance with E3 pulse mask
  Software-configurable E3 national service bits
  Alarm monitoring
  Performance data collection
   Framing-pattern errors
   FEBE counts

Reliability and availability

  Single SPA software reset


RFC 2496 MIB (T3 MIB) and T1.231 MIB

Network management

Simple Network Management Protocol (SNMP)

Physical specifications

  Weight: 0.75 lb (0.34 kg)
  Height: 0.8 in. (2.03 cm) (single height)
  Width: 6.75 in. (17.15 cm)
  Depth: 7.28 in. (18.49 cm)


  2-port: 7.7W maximum
  4-port: 8.4W maximum

Compliance and agency approvals

CE Marking


  UL 60950
  CSA 22.2 No.60950
  IEC 60950
  EN 60950
  AS/NZS 3260


  CFR47 Part 15
  ICES 003
  CISPR 22
  AS/NZ 3548

Telecom (T3)

  ANSI T1 107
  T1 404
  AT&T 54014

Telecom (E3)


Environmental specifications

  Operating temperature: 41 to 104°F (5 to 40°C)
  Storage temperature: -38 to 150°F (-40 to 70°C)
  Operating humidity: 5 to 85% relative humidity
  Storage humidity: 5 to 95% relative humidity

Ordering Information

To place an order, visit the Cisco Ordering Home Page and refer to Table 2.

Table 2.       Ordering Information

Product Name

Part Number

Cisco 2-Port Clear Channel T3/E3 Shared Port Adapter Version 2


Cisco 4-Port Clear Channel T3/E3 Shared Port Adapter Version 2


T3 or E3 Cable, 1.0/2.3 RF to mini BNC-Female, 10 Feet


T3 or E3 Cable, 1.0/2.3 RF to mini BNC-Male, 10 Feet


T3 or E3 Cable, 1.0/2.3 RF to Open end, 25 Feet


Service and Support

Cisco offers a wide range of services programs to accelerate customer success. These innovative services programs are delivered through a unique combination of people, processes, tools, and partners, resulting in high levels of customer satisfaction. Cisco services help you protect your network investment, optimize network operations, and prepare your network for new applications to extend network intelligence and the power of your business. For more information about Cisco services, refer to Cisco Technical Support Services or Cisco Advanced Services.

For More Information

For more information about the Cisco SPA/SIP portfolio, visit or contact your local Cisco account representative.