Polycom MGC 100-Video Lag

[VTCDAVE]

We have a MGC 100 running version 8.0 carded for a small amount of IP and more ISDN. We use Continuous Presence with People Plus Content with the lead site Ip and the rest ISDN. We have done 384K calls successfully to 23 sites at 384K with the Codecs (all VS4000) with the Visual Concert. When we tried to ramp up to 768, we have the issue of breakup on video(9 box view) and graphics. The video would lock up for a few seconds when there was movement but then return when people stood still. The only items that changed were the increased speed of call 384 vs 768 and the origination location. We had the network engineers check the IP line for packet loss and they said it was OK. The video and audio cards are about 5 years old. We have a couple of video and audio cards and 1 Video + and 1 Audio + card.

Do we have a lack of video resource issue on the MGC. Any help is appreciated.

Dave

[Sean Lessman]

We had the network engineers check the IP line for packet loss and they said it was OK.

Can you describe how they did this? The most common mistake is the network engineer looks in the router or switch and says "I dont see any packet loss". Doing this doesn't tell you anything about packets that were lost before or after the router/switch.

The best way to monitor packet loss is see what leaves one VTC unit and compare it to what arrives at the other.

Sean

[VTCDAVE]

We saw packet loss on both ends. I believe the losses build up and as time goes by, cause a deterioration of quality. The network guys never tell us what they are doing or what they have done. What you described is exactly what happened. I am going to run tests from another location so I can narrow it down to that location. I prefer to do all ISDN to avoid the network issues that always pop up and are hard to deal deal with.

[VTCDAVE]

We found that the port setting for IP address that the MGC uses to dial H323 was dropping packets. Port setting changed and all seems stable.