Cisco Headend System Release 2.7 Installation Guide
What's Fixed?
4022900 Rev C
5
What's Fixed?
Implemented CRs
This section provides a description of the CRs implemented in GQAM software
version 4.2.1 for issues found in GQAM software version 4.0.17 and later.
CR 79852: Under Certain Conditions, the GQAM May Calculate Incorrect CRC in
IGMPv3 Messages
In previous versions of GQAM software, IGMPv3 query responses used a fixed
length value to calculate the message CRC. If the IP header contains additional data,
this CRC value is not correct and some switches and routers may reject the response.
The result of the bad CRC rejection is a momentary video freeze every two minutes.
CR 79852 corrected this issue.
CR 80982: GQAMs Were Occasionally Unable to Properly Tune to Frequencies
Between 800 and 860 MHz at Ambient Temperatures Above 45°C (113°F)
In earlier versions of GQAM software, when high ambient temperatures
(>45°C/113°F) occurred, the GQAM was occasionally unable to operate at
frequencies between 800 and 860 MHz. CR 80982 contains a minor adjustment to an
integrated circuit (IC) used for frequency synthesization that provides reliable
tuning characteristics at elevated temperatures.
CR 81948: GQAM Output PCR Jitter Now Conforms With Specification
In earlier versions of GQAM software, output program clock reference (PCR) jitter
occasionally exceeded 500 nanoseconds. This did not cause video impairments.
CR 81948 corrected this issue.
CR 82363: Alarm Manager Now Returns the Correct Pointer to the Buffer Pool
Previously, memory corruption could occur when the Alarm Manager queue
became full. This corruption prevented the GQAM from processing any new
sessions. The only way to clear this condition was to reboot the GQAM. Now the
Alarm Manager returns the correct pointer to the buffer pool. CR 82363 corrected
this issue.