Choppy Video - 10 base T Hub Culprit?

[patrick.hurley]

I have a customer that is using a DSL connection with 1.5Mbps down and 384kbps up to connect between two locations. It is private atm vcc DSL but ubr. PVC is built between DSLAM and their ATM interface on their router. No Internet IP router hops.

He has a 1720 router with a 10baseT hub, not switch at one end and a 7200 with a switch at the other. We connect two Polycom Viewstations at 128kbps and his quality is terrible at the 10BaseT hub end and fine at the switch end.

Can half duplex nature of the hub be causing the problem?

[Markus Schneider]

That could definitely be a cause for problems (or minimally a significant contributing factor). Unless you can get some statistics off of the hub, the only way you'll know for sure how much of a factor it is would be to plug the viewstation straight into the router and see how the quality is then.

[pcarter]

I found a 10BaseT hub in an old phone closet in our network. After replacing it, video calls cleared up significantly. I hope it works for you.

[sachon]

Don't think its the hub unless there is something defective with it. Anything else plugged into the hub? If not, my guess is that its the 1720 router. Try using a 25xx or better to see if that clears the issue.

[patrick.hurley]

Why would you think it was the router? A 1721 should be able to pass 128Kbps of Video over IP traffic unless this is an IOS bug

[acsalas]

I had the same issue and replaced it with a small workgroup switch. H.323 video doesn't play well with shared contention mediums, i.e. hubs. Another issue that I found played a big role was to select Half/10, no auto-sensing!!!

Good luck, you'll get it.

Anthony