External Timing Ports - Juniper E SERIES BROADBAND SERVICES ROUTERS 11.3.X - ERX HARDWARE GUIDE REV 26-9-2010 Hardware Manual

ERX 11.3.x Hardware Guide

External Timing Ports

50
Only ERX7xx and ERX14xx models have external timing ports and alarm leads located
on the SRP I/O module. All ERX routers have console ports located on the SRP I/O
module. See Table 7 on page 50 for details on each component.
Table 7: SRP I/O Ports
Port
Alarm leads (ERX7xx and
ERX14xx models only)
External timing ports (ERX7xx
and ERX14xx models only)
Management console ports
NOTE: This section applies to ERX7xx and ERX14xx models only. The ERX310
router does not support external timing.
The SRP I/O module has two input ports for external clock sources. These ports provide
a way to ensure that the router system clock remains synchronized with the network's
system clock. The primary clock is labeled A; the secondary, redundant clock is labeled
B.
Use the connectors appropriate for your locale (European or North American standard):
European—Two 75-ohm E1 2.048-Mbps inputs with BNC connectors
North American—Two 100-ohm T1 inputs with three pin wire-wrap connectors. Pins
are labeled T (tip), G (ground), and R (ring). We recommend using 26-AWG wire
minimum.
NOTE: Use shielded cables to connect the external clock sources to the
clock source input ports.
Description
Six terminal blocks for external alarm contacts; use a minimum
26-AWG for each (currently not implemented)
Two 3-pin wire-wrap posts for US external clock sources;
primary (A) and secondary (B)
Two BNC connectors for E1 clock sources; primary (A) and
secondary (B)
One 10/100Base-T Ethernet management port with an
RJ-45 connector
One RS-232 console port with a DB-9 connector for VT100
management access
Copyright © 2010, Juniper Networks, Inc.