Specifications

1-3
Cisco MWR 2941 Mobile Wireless Edge Router Software Configuration Guide, Release 12.2(33)MRB
OL-21227-02
Chapter 1 Cisco MWR 2941 Router Overview
Features
Features
The following sections describe the features available in the Cisco MWR 2941 router.
Cisco Pseudowire Emulation Edge-to-Edge
Cisco Pseudowire Emulation Edge-to-Edge (PWE3) allows you to transport traffic using traditional
services such as E1/T1 over a packet-based backhaul technology such as MPLS or IP. A pseudowire
(PW) consists of a connection between two provider edge (PE) devices that connects two attachment
circuits (ACs), such as ATM VPIs/VCIs or E1/T1 links. Figure 1-1 shows a sample pseudowire
topology.
Figure 1-1 Cisco MWR 2941 Router in a PWE3—Example
PWs manage encapsulation, timing, order, and other operations in order to make it transparent to users;
the PW tunnel appears as an unshared link or circuit of the emulated service.
There are limitations that impede some applications from utilizing a PW connection. For more
information, see the section describing the PW service.
Cisco supports the following standards-based PWE types:
• Structure-agnostic TDM over Packet, page 1-3
• Structure-aware TDM Circuit Emulation Service over Packet-Switched Network, page 1-4
• Transportation of Service Using ATM over MPLS, page 1-4
• Transportation of Service Using Ethernet over MPLS, page 1-4
Structure-agnostic TDM over Packet
SAToP encapsulates TDM bit-streams (T1, E1, T3, E3) as PWs over PSNs. It disregards any structure
that may be imposed on streams, in particular the structure imposed by the standard TDM framing.
The protocol used for emulation of these services does not depend on the method in which attachment
circuits are delivered to the PEs. For example, a T1 attachment circuit is treated the same way for all
delivery methods, including: PE on copper, multiplex in a T3 circuit, mapped into a virtual tributary of
ATM/TDM ATM/TDMxconnectxconnect
MPLS/IP
Pseudowire
Emulated Circuit
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