This module provides command line interface (CLI) commands for configuring Packet-over-SONET/SDH (POS) on the Cisco CRS Router.
To use commands of this module, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using any command, contact your AAA administrator for assistance.
describes the Cisco IOS XR commands used to configure, monitor, and
troubleshoot Packet-over-SONET/SDH (POS).
POS provides a
method for efficiently carrying data packets in SONET or Synchronous Digital
Hierarchy (SDH) frames. High-bandwidth capacity and efficient link utilization
are characteristics that make POS largely preferred for building the core of
data networks. POS uses PPP in High-Level Data Link Control (HDLC)-like framing
for data encapsulation at Layer 2 (data link) of the Open System
Interconnection (OSI) stack. This method provides efficient packet delineation
and error control.
In addition to
high-bandwidth efficiency, POS offers secure and reliable transmission for
data. Reliable data transfer depends on timing integrity.
The real-time POS functionality is performed in hardware, according to the hardware configuration setup. Configured hardware events are detected by the framer application-specific integrated circuits (ASICs) and the control is passed to the software. The generic POS driver is responsible for providing a mechanism to configure the hardware on a per-interface basis, to handle interface state transitions, and to collect POS-related statistics.