Juniper ACX2000 Configuration Guide

after synchronization in SONET/SDH. Traditional Ethernet nodes, which do not support
Synchronous Ethernet, do not carry synchronization from one node link to another.
Synchronous Ethernet–capable nodes however can synchronize their chassis clock to a
clock recovered from an interface connected to an upstream clock master. After this,
the clock is used to time data sent to downstream clock slaves, forming a synchronization
trail from a Primary Reference Clock (PRC) to Ethernet equipment clocks (EECs) and
transferring frequency synchronization along the trail.
The ITU-T G.8264 specification defines the Synchronization Status Message (SSM)
protocol and its format for Synchronous Ethernet to ensure interoperability between
Synchronous Ethernet equipment used for frequency transfer—for example, SONET/SDH.
Synchronous Ethernet provides stable frequency synchronization to a PRC and is not
affected by load on the network. However, it requires that all the nodes from the PRC to
the last downstream node are Synchronous Ethernet capable. Synchronous Ethernet is
a recommended technology for mobile networks that require frequency-only
synchronization—for example, 2G or 3G base stations.
Related
Documentation
Synchronous Ethernet Overview•
TDM CESoPSN Overview
Circuit Emulation Service over Packet-Switched Network (CESoPSN) is an encapsulation
layer intended to carry NxDS0 services over a packet-switched network (PSN). CESoPSN
enables pseudowire emulation of some properties of structure-aware time division
multiplexed (TDM) networks.
Particularly, CESoPSN enables the deployment of bandwidth-saving fractional
point-to-point E1 or T1 applications as follows:
•
A pair of customer edge (CE) devices operate as though they were connected by an
emulated E1 or T1 circuit, which reacts to the alarm indication signal (AIS) and remote
alarm indication (RAI) states of the devices’ local attachment circuits.
•
The PSN carries only an NxDS0 service, where N is the number of actually used time
slots in the circuit connecting the pair of CE devices, thus saving bandwidth.
Related
Documentation
Configuring TDM CESoPSN on ACX Series Routers Overview on page 108•
• Configuring CESoPSN Encapsulation on DS Interfaces on page 205
• Configuring CE1 Channels Down to DS Interfaces on page 218
Configuring TDM CESoPSN on ACX Series Routers Overview
Structure-aware time division multiplexed (TDM) Circuit Emulation Service over
Packet-Switched Network (CESoPSN) is a method of encapsulating TDM signals into
CESoPSN packets, and in the reverse direction, decapsulating CESoPSN packets back
into TDM signals. This method is also termed as Interworking Function (IWF). The following
Copyright © 2017, Juniper Networks, Inc.108
ACX Series Universal Access Router Configuration Guide

Juniper ACX2000 Specifications

General

Brand	Juniper
Model	ACX2000
Category	Network Router
Language	English