Juniper ACX2000 Configuration Guide

NOTE: ACX500 routers do not support 10 MHz in and out. ACX500 routers
supports GPS input through SubMiniature version A (SMA) connector.
•
ACX500 routers contain integrated GPS receiver, pulse-per-second (PPS) in and out,
and Gigabit Ethernet ports (RJ45 and SFP).
•
Synchronous Ethernet (SyncE) is supported based on the ITU G.8261, G.8262, and
G.8264 specifications with line timing for ge and xe ports.
Synchronous Ethernet is a key requirement for circuit (emulation) services and mobile
radio access technologies. Synchronous Ethernet supports sourcing and transfer of
frequency for synchronization purposes for both wireless and wireline services and is
primarily used for mobile backhaul and converged transport.
•
The Precision Time Protocol (PTP) 1588v2—compliant ordinary slave clock estimates
the time offset from the PTP master clock and tries to align its own time and frequency
with that of the master. PTP supports sourcing, transfer of frequency, and phase
synchronization. Also, PTP can be used for mobile backhaul when phase synchronization
is required, such as in Long Term Evolution-Time Division Duplex (LTE-TDD)
infrastructures.
Related
Documentation
Global Positioning System (GPS) and the ACX Series Routers on page 306•
• Understanding Interfaces on ACX Series Universal Access Routers on page 94
• Synchronous Ethernet Overview on the ACX Series Universal Access Routers on page 107
• IEEE 1588v2 Precision Timing Protocol (PTP) on ACX Series Universal Access Routers
on page 237
External Clock Synchronization Overview for ACX Series Routers
The ACX Series Universal Access routers support external clock synchronization and
automatic clock selection for Synchronous Ethernet, T1 or E1 line timing sources, and
external inputs. Configuring external clock synchronization and automatic clock selection
requires making clock selection, quality level (QL), and priority considerations. The clock
source selection algorithm is used to pick the two best upstream clock sources from
among all the various sources, based on system configuration and execution criteria such
as QL, priority, and hardware restrictions.
Automatic Clock Selection
With automatic clock selection, the system chooses up to two best upstream clock
sources. The system then uses the clock recovered from one of the sources to lock the
chassis clock. If an upstream clock with acceptable good quality is not available or if the
system is configured in free-run mode, the system uses the internal oscillator. The
following automatic clock selection features are supported for Synchronous Ethernet,
T1 or E1 line timing sources, and external inputs:
Copyright © 2017, Juniper Networks, Inc.226
ACX Series Universal Access Router Configuration Guide

Juniper ACX2000 Specifications

General

Brand	Juniper
Model	ACX2000
Category	Network Router
Language	English