User`s guide

XSR User’s Guide 51
4
Configuring T1/E1 Interfaces
Overview
The XSR provides a T1/E1 subsystem on a single NIM-based I/O card with a
maximum of two installed NIMs. Depending on the card type and series,
each card can support 1, 2 or 4 T1 or E1 physical ports.
You can select either T1, at 1.544 Mbps interface rate per port, or E1, at
2.048 Mbps interface rate per port. In both operational modes, the interface
can work either in full rate T1/E1 mode (the complete available line interface
rate is assigned to one user), fractional T1/E1 mode (only one channel group is
assigned, with less than the total available number of timeslots on a T1/E1
line configured per physical port) or in channelized mode (more than one
channel group is configured per physical port).
In fractional/channelized mode, up to 31 DS0 channels can be assigned on E1
interfaces and up to 24 DS0 channels can be assigned on T1 interfaces. The
rate (line speed) of basic channel (DS0) can be configured at 56 or 64 Kbps.
Features
The following features are offered on the T1/E1 interfaces:
 Integrated CSU/DSU
 Full-rate, channelized and fractional
 Short and long haul symmetrical line interfaces with 100/120 ohm
impedance using RJ-45/48C or 49C connectors
 Support for local and remote loopback
 Support for an IP interface as a loopback (refer to the CLI Reference
Guide for an example)
 Timing - line and internal
 Framing - T1: SF, ESF; E1: CRC4, NO-CRC4