Cisco MGX 8230 Software

Field Notice: Noise on Voice Internetworking Service Module (VISM) in Bulk Distribution Mode

March 09, 2004

Products Affected




Running VISM Software 3.1.2


Running VISM Software 3.1.2

Problem Description

Voice coming from the IP side, MGX bus side, of the Voice Internetworking Service Module (VISM) directed to the TDM side, E1 port, may experience a distortion with a cracking noise overlapping the speech


This problem is manifested when using Bulk Distribution mode to pass E1 from Service Resource Module-Enhanced (SRME) to VISM-PR-8E1 or VISM-8E1. This problem may occur using any compression type. Fax passthrough data is also affected by this anomally.

Problem Symptoms

User may hear distortion with a crackling noise over speech. Fax passthrough will fail.


Workaround: None

Solution: Upgrade VISM-PR software to 3.1.3 or later 3.1 release or any 3.2 release.

Note that this anomaly is not a hardware issue. Replacing the MGX-VISM-PR will not solve this problem.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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