Router User Manual

Cabling ERX Routers
The SRP I/O module has two input po rts for external clock sources.
These ports pr
ovide 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 Americ
an standard):
European—Tw
o 75-ohm E1 2.048-Mbps inputs with BNC connectors
North Americ
an—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 minimu m.
NOTE: Use shi
elded cables to connect the external clock sources to the clock
source input ports.
Cabling the SRP I/O Module 57