Cisco Model D-PCG1000 PowerKEY CAS Gateway Technical References
July 2003
Operations Alert Bulletin
Replace MQAM v1.3.2 With MQAM v1.3.3
Purpose
This alert bulletin notifies cable service providers that MQAMs operating with
software version 1.3.2 can accumulate excessive pending “responder messages” for
the Digital Network Control System (DNCS), which results in a buffer overflow that
can eventually interrupt two-way communication between the MQAM and the
DNCS.
The new MQAM software version 1.3.3 (MQAM 1.3.3) prevents the accumulation of
The new MQAM software version 1.3.3 (MQAM 1.3.3) prevents the accumulation of
responder messages and the subsequent loss of communication.
Audience and Sites Affected
This alert bulletin is written for Digital Network Control System (DNCS) operators
currently operating System Release (SR) 1.5.1 Service Pack 1 or SR 1.5.1 Service Pack
2 releases and Cisco Services engineers.
Note: Customers upgrading to SR 2.1 or SR 3.0 will not retain MQAM software
Note: Customers upgrading to SR 2.1 or SR 3.0 will not retain MQAM software
version 1.3.2 (MQAM 1.3.2) during the upgrade, and therefore do not require
MQAM 1.3.3.
Background
An MQAM running 1.3.2 software can eventually over fill its buffer with responder
messages from the DNCS during normal system operations.
For example, when building a significant amount of xOD (anything-On-Demand)
For example, when building a significant amount of xOD (anything-On-Demand)
transactions a large number of two-way messages are exchanged between the
MQAM and DNCS. If the number of messages sent from the MQAM exceeds
approximately 65,000, the MQAM will enter a “non-responding” state. At this point,
messages sent from the DNCS will begin to accumulate in the MQAM buffers.
Eventually the buffers become filled, which causes the MQAM to lose
communication with the DNCS.