Juniper ACX2000 Configuration Guide

Figure 14: Pseudowire Encapsulation with SAToP
PE2
PE1CE1 CE2
PSN tunnel
Pseudowire 1
Pseudowire 2
Attachment Circuit Attachment Circuit
Emulated Service
Native service Native service
g016956
Pseudowire traffic is invisible to the core network, and the core network is transparent
to the CEs. Native data units (bits, cells, or packets) arrive via the attachment circuit, are
encapsulated in a pseudowire protocol data unit (PDU), and carried across the underlying
network via the PSN tunnel. The PEs perform the necessary encapsulation and the
decapsulation of the pseudowire PDUs and handle any other function required by the
pseudowire service, such as sequencing or timing.
Related
Documentation
Configuring SAToP Emulation on Channelized T1 and E1 Interfaces on page 191•
Ethernet Ring Protection Switching Overview
Ethernet ring protection switching (ERPS) helps achieve high reliability and network
stability. Links in the ring will never form loops that fatally affect the network operation
and services availability. The basic idea of an Ethernet ring is to use one specific link to
protect the whole ring. This special link is called a ring protection link (RPL). If no failure
happens in other links of the ring, the RPL blocks the traffic and is not used. The RPL is
controlled by a special node called an RPL owner. There is only one RPL owner in a ring.
The RPL owner is responsible for blocking traffic over the RPL. Under ring failure conditions,
the RPL owner is responsible for unblocking traffic over the RPL. A ring failure results in
protection switching of the RPL traffic. An automatic protection switching (APS) protocol
is used to coordinate the protection actions over the ring. Protection switching blocks
traffic on the failed link and unblocks the traffic on the RPL. When the failure clears,
revertive protection switching blocks traffic over the RPL and unblocks traffic on the link
on which the failure is cleared.
NOTE: ERPS on AE interfaces is not supported on ACX Series routers.
The following standards provide detailed information on Ethernet ring protection
switching:
•
IEEE 802.1Q - 1998
•
IEEE 802.1D - 2004
•
IEEE 802.1Q - 2003
•
ITU-T Recommendation G.8032/Y.1344 version 1 and 2, Ethernet Ring protection
switching
•
ITU-T Y.1731, OAM functions and mechanisms for Ethernet-based networks
111Copyright © 2017, Juniper Networks, Inc.
Chapter 4: Configuring Interfaces and Chassis

Juniper ACX2000 Specifications

General

Brand	Juniper
Model	ACX2000
Category	Network Router
Language	English