Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
New Member

H.323 packet loss using 6509 switches

I'm experiencing an issue with audio and video packet loss on our LAN using 6509 switches. The video units we are using are Polycom FX/H.323 units. In our offices with 2900 and 3500 switches, we have no error problems, but when we moved into a facility with 6509 swithes (10/100 telco cards) we started having packet loss and degraded audio/video quality. Does anyone have any ideas on this one? Thanks

7 REPLIES
Cisco Employee

Re: H.323 packet loss using 6509 switches

One thing to note is that most Polycom models only have 10mbps + 1/2 duplex interfaces, which may not properly autonegotiate with the Switch. "show port" on the switch will likely display the port status as a-100 + a-full. This is a common problem that we see in nearly every installation, and often results in packet loss.

The Polycom FX model is the only one that has a 100mbps interface, so this may not be the solution to your problem. However, I would still recommend reviewing the port status, and try manually setting the ports to 10+1/2, or 100+1/2, and see if the packet loss decreases (keep in mind that some packet loss is inevitable on a 1/2 duplex interface) to an acceptable level.

Kevin

New Member

Re: H.323 packet loss using 6509 switches

Keep Kevin's thought in mind when deploying IP phones as well. Cisco only supports auto detection wih IP phones and you cannot configure IP phones for speed and duplex opeation. On a hardcoded 100 full switched port, an IP phone will negotiate its end @ 100 1/2!! This causes intermittent voice quality issues. USE AUTO DETECT WITH IP PHONES!

New Member

Re: H.323 packet loss using 6509 switches

I have tried all the suggestions above to no avail. We are currently working a ticket with TAC, but I'm still looking for any other ideas.

Thanks,

Andras

New Member

Re: H.323 packet loss using 6509 switches

My first impression is, "it's the new cable infrastructure"! Have you installed a 3500 or 2900 to verify that it works in the "new" office? One would think it would be a quick test.

Are you using redundant Sups?

We have had faulty redundant Sups (L2 only) in several 6009's, not 6509's cause the telco 10/100 card in the first slot down from the redundant sup to intermitantly connect while trying to load the customer preferred version of IOS, if we hard coded the speed of the uplink connection (1st port on the 48 port telco card/slot 8 in our case) it would allow us to succesfully load the code, if we didn't hard code it it would not allow us to load the IOS until we removed the redundant sup. It would work great with one sup.

This might not help but is definitly worth a try. When we swapped the sups, the know primary sup would fail and the 6009 would failover to slot 2!

If you are using an MSFC, which version? There has been lot's of problems/enhancements with MSFC's over the last year as well as the supervisors. jak

New Member

Re: H.323 packet loss using 6509 switches

Thanks for the response. 1st thing we tried was different switches. The systems work fine with 29xx and 35xx switches.

Here's the latest. After weeks of trying to get ahold of polycom tech support, we finally received an answer from them that the NIC in the Polycom Viewstation FX H.323 might not be compatible with the 65xx series of switches. We've actually tested this alot in the last couple of months, and can even say that the errors exist when the units are plugged into a 3500 switch, run over 1000sx fiber to a 6509, then back to a seperate 3500, also via 1000sx, to another polycom. We're working with both cisco and polycom on this at this point, and I'll post any updates.

ab

New Member

Re: H.323 packet loss using 6509 switches

Hello. Are the end devices on the same network or being routed (L3 / RSM) at the 6509 between VLANs? My thought was if you are traversing a router at some point, custom or priority queueing may be a solution.

Bill

New Member

Re: H.323 packet loss using 6509 switches

Bill-

There is no routing when the error occurs. I can however route between units, both on a lan and wan, when using 29xx or 35xx switches.

Andras

242
Views
0
Helpful
7
Replies
CreatePlease to create content