Cisco ASR 1000 Series Software Configuration Guide

Either the SPA-1CHOC3-CE-ATM or the SPA-24CHT1-CE-ATM must be installed in ASR-1000-SIP10 or
ASR-1000-SIP40 before the SIPs can be used in the Cisco ASR 1000 Series Routers. A maximum of four
SPA-1CHOC3-CE-ATM or SPA-24CHT1-CE-ATM can be installed in each SIP; these SPAs can be of
different models. You can install a SPA in the SIP either before or after you insert the SIP into the router
chassis. This enables you to perform online insertion and removal (OIR) operations either by removing the
individual SPAs from the SIP or by removing the entire SIP (and the SPAs it contains) from the chassis.
Pseudowire Emulation over Packet (PWEoP) is one of the key components in the process of migrating
customers to a packet-based multiservice network. CEoP, which is a subset of PWEoP, is a technology used
to migrate from legacy TDM networks to all-packet networks, and transparently provide transport for legacy
applications over a packet network. The SPA-1CHOC3-CE-ATM represents an actual physical connection.
Many service providers and enterprises operate both packet-switched networks and time-division multiplexing
(TDM) networks. These service providers and enterprises have moved many of their data services from the
TDM network to their packet network for scalability and efficiency. Cisco provides routing and switching
solutions that are capable of transporting Layer 2 and Layer 3 protocols, such as Ethernet, IP, and Frame
Relay. While most applications and services have been migrated to the packet-based network, some, including
voice and legacy applications, still rely on a circuit or a leased line for transport. The SPA-1CHOC3-CE-ATM
and SPA-24CHT1-CE-ATM implement CEoP by transporting circuits over a packet-based network. The
SPA-1CHOC3-CE-ATM and SPA-24CHT1-CE-ATM SPAs help service providers and enterprises migrate
to one-packet networks that are capable of efficiently delivering both data and circuit services.
CEoP Frame Formats
The SPA-1CHOC3-CE-ATM, SPA-2CHT3-CE-ATM, and SPA-24CHT1-CE-ATM support the structured
or Circuit Emulation Services over Packet Switched Networks (CESoPSN) and the Structure-Agnostic TDM
over Packet (SAToP) encapsulations.
Circuit Emulation Services over Packet Switched Network Mode
The CESoPSN mode encapsulates the T1/E1 structured (channelized) services over PSN. The structured mode
(CESoPSN) identifies framing, and sends only the payload, which can either be channelized T1s within DS3
or DS0s within T1. DS0s can be bundled to the same packet. The CESoPSN mode is based on IETF RFC
5086.
SPAs can aggregate individual interfaces and flexibly bundle them together. They can be configured to support
either structured or unstructured CES modes of operation per T1/E1/J1 interface and clear-channel DS3
interface. Effective from Cisco IOS XE Release 3.6.0S, DS3 supports both the CESoPSN and the SAToP.
They are supported on the 1-Port Channelized OC-3 STM1 ATM CEoP SPA channelized to T1 or E1 and on
the 24-Port Channelized T1/E1 ATM CEoP SPA.
Each supported interface can be configured individually to any supported mode. The supported services
comply with IETF and ITU drafts and standards.
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide, Cisco IOS XE
Everest 16.5
OL-14127-17 457
Overview of the Circuit Emulation over Packet Shared Port Adapter
CEoP Frame Formats

Cisco ASR 1000 Series Specifications

General

Brand	Cisco
Model	ASR 1000 Series
Category	Network Router
Language	English