User`s guide

48 XSR User’s Guide
Overview of WAN Interfaces Chapter 3
Managing LAN/WAN Interfaces
Overview of WAN Interfaces
The XSR supports as many as six serial cards (in an XSR-3250), each of which
can support four ports for a maximum of 24 serial ports. Each port is
individually configurable regarding speed, media-type, and protocol.
The Serial WAN interface performs the following functions:
 Transmit packets given by the protocol layer onto a serial link.
 Receive packets from a serial link and pass up to the protocol layer.
 Allow CLI configuration commands to be issued.
 Accumulate all MIB-II (RFC-1213) interface statistics regarding the
transmission and reception of bytes and packets.
WAN Features
The XSR supports the following WAN interface features:
 Alarms/events - For a complete list, refer to “Alarms/Events and
System Limits” on page 355 in this manual.
 Interfaces - The following interface types can be configured using the
media-type command:
– RS232 (also known as V.28) (default)
– RS422 (also known as RS-530)
– RS449 (also known as V.36)
– RS530A
– V. 3 5
– X.21
 Either Sync or Async mode is set by using
physical-layer.
 Encoding - On Sync interfaces,
nrzi-encoding sets NRZI encoding
(NRZ encoding is the default).
 Clocking speed - For Sync interfaces, an external clock must be
provided. Acceptable clock values range from 2400 Hz to 10 MHz.
For Async interfaces, the clock is internally generated and can be set
to the following values using
clock rate:
– 2400 Kbps
– 4800 Kbps