Document ID: 10767
Contents
Introduction
Prerequisites
Requirements
Components Used
Conventions
Product Affected
Description
Workaround
Related Information
Introduction
The customer premises equipment (CPE) receives an alarm indicator signal (AIS) that shows a loss of signal (LOS) during connection rerouting.
Prerequisites
Requirements
There are no specific requirements for this document.
Components Used
This document is not restricted to specific software and hardware versions.
Conventions
Refer to Cisco Technical Tips Conventions for more information on document conventions.
Product Affected
BPX 8.4 - AXIS 4.0/CESM
Description
A problem occurred during connection rerouting on a BPX switch. The Circuit Emulation Service Module (CESM) receives an under-run for a few milliseconds, so it sends an AIS signal (all 1s), as per the Circuit Emulation (CE) standard.
Because it operates in unframed mode, this AIS signal does not contain any framing bits. This can cause problems such as loss of frame (LOF) at the CPE. Therefore, the problem is determined not to be due to the rerouting mechanism.
Workaround
In case of short under-runs, increasing the cell delay variation (CDV), or the egress bufsize, can be used as a workaround. However, this also introduces that much delay. The maximum value for the CDV can be 65,535 microseconds.
Related Information
- Cisco WAN Switching Solutions
- Guide to New Names and Colors for WAN Switching Products
- Technical Support & Documentation - Cisco Systems
| Updated: Jan 12, 2006 | Document ID: 10767 |