A common bug of HD3 series terminals

An issue of call establishment delay when conferencing with Polycom MCU RMX2000

The situation was

1. Meeting entities
1). Polycom MCU: Polycom RMX 2000, version ID: 8.3.0
2). Kedacom HD3 H600 SP4

2. Call scenario
HD3 joined a multi-point conference with RMX2000.
1) All the H.225 and H.245 processes were OK.
2) OLC request from both side returned with ACK.
3) The audio packets could be captured right after the OLC ACK.
4) The video packets from HD3 sent right after got the OLC ACK from the MCU.
5) HD3 could not receive any video packets from the MCU.
6) HD3 waiting for a terminalYouAreSeeing conferenceIndication from the MCU to switch the status to InConf…
7) 20 seconds later we finally got the terminalYouAreSeeing indication. Along with the terminalYouAreSeeing, we got the video.

Seems the MCU was waiting for a command to switch its status to an established-mode.
But we just don’t know what it is, even after tested lot’s of MTs from Polycom, Tendburg, HUAWEI, ZTE, which all of them just working fine.

What we got is only that it must be a HD3’s bug.

After a long long times comparison with the pcap file, the only difference was the H.224 channel.
We did not open the H.224(FECC) channel together with the audio, video and H.239 channel, this caused the RMX2000 to wait 20 seconds to send the terminalYouAreSeeing indication.
It’s a yet-another-long-existing bug, we survived a long time, but today we finally ran into the consequence.

PCAP file: a-common-bug-of-hd3-series-terminals.pcap

Failed to establish H.460 call through Polycom MCU issue

Details of the issue:

The situation is H600 can establish H.460 calls with most of the GKs around the world, but failed to a Polycom GK.
Allow me to explain the details of this issue:
1. Caller: Group500, callee: H600, GK/MCU: Polycom RMX 2000
2. Group500 sent a call to GK with callModel set to gatekeeperRouted, calling target: H600
3. GK sent H.460 SCI to H600
4. H600 replied SCR to GK
5. H600 established a H.225 TCP connection to the Polycom GK successfully
6. H600 sent facility to GK.
7. Polycom GK shutdown the H.225 TCP connection from H600 actively, and call terminated. Continue reading “Failed to establish H.460 call through Polycom MCU issue”