Cisco ASR 903 Hardware Installation Guide

Connecting Timing Cables
When installing the cabling to the RSPs, we recommend that you leave a service loop of extra cabling
sufficient to allow for fan tray removal.
Note
Connecting Cables to the BITS Interface
The following steps describe how to connect a cable to the router BITS port:
Step 1
Confirm that the router is powered off.
Step 2
Connect one end of the cable to the BITS port using a straight-through, shielded RJ48C-to-RJ48C cable.
Step 3
Connect the other end to the BTS patch or demarcation panel at your site.
Step 4
Turn on power to the router.
For information about the BITS port pinouts, see Troubleshooting.
Use of two BITS sources or a Y-cable is optional. Each BITS input port is routed to both RSPs, so that SETS
device on each RSP has visibility to both BITS inputs.
Note
To comply with the Telcordia GR-1089 NEBS standard for electromagnetic compatibility and safety, connect
the BITS ports only to intra-building or unexposed wiring or cable. The intrabuilding cable must be shielded
and the shield must be grounded at both ends. The intra-building port(s) of the equipment or subassembly
must not be metallically connected to interfaces that connect to the OSP or its wiring. These interfaces are
designed for use as intra-building interfaces only (Type 2 or Type 4 ports as described in GR-1089-CORE)
and require isolation from the exposed OSP cabling. The addition of Primary Protectors is not sufficient
protection in order to connect these interfaces metallically to OSP wiring.
Warning
Connecting Cables to a GNSS Interface
A Y-cable is required to connect to a primary and backup RSP in order to ensure that the router continues
to transmit timing signals in the event of a network failure. For a mini-coax connection, this Y-cable can
be part number CAB-BNC-7INY (7 inch BNC Y-cable). For an Ethernet connection, this Y-cable can be
a RJ45 Cat5 1-to-2 splitter (3 female port RJ45 connector).
Note
When installing the cabling to the RSPs, we recommend that you leave a service loop of extra cabling
sufficient to allow for fan tray removal.
Note
Cisco ASR 903 Aggregation Services Router Hardware Installation Guide
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Installing the Cisco ASR 903 Router
Connecting Timing Cables

Cisco ASR 903 Specifications

General

Brand	Cisco
Model	ASR 903
Category	Network Router
Language	English