sundance-communications.com/forum Forums VOIP Phones & IP PBX Networking Need a little advice !!!!!

Have a good customer that is running an Allworx 6x VOIP Server...they have been having problems with packet delay / jitter (which is causing problems with one way audio etc;) Anyway did a packet capture yesterday for them and found clean audio at the lan port of the Allworx which basically say's the problem lies in the cust. network..i.e; switch..wiring..
Wiring is all new and syst has been running fine 8 + months no problems..I suspect a problem with the switch..Cisco 37xx series....
Can anyone shed some light on what might cause this..? i.e; settings...bad port....???? Just looking for some idea's as to where to attack this thing as they want me to help their IT (go figure) out !!!! Thanks

I don't know Allworks,but sometimes the easiest things are over looked. When i've run into this i have found most times it's a circuit problem. Just throwing a idea out. Maybe it will help.

The wiring being all new doesn't really mean much unless it has been certified.

Has there been any type of construction or repair work done on-site? Anybody move anything around, like rearranging the office or something.

As we all know, the right hand doesn't always know what the left hand is or has done.

If you can't find anything outside of the switch, I would tell them to call an Cisco tech in. I do some work on Cisco equipment, but when it get down to figuring out if a switch or port is dieing, I let the certified people take over. I just don't have the tools to dig that deep into them.

Well, that's the deal I have eliminated the trunking..they have SIP trunks and the packet capture is clean on the trunk side..it's definately a problem in the network..as far as the wiring we installed it..and it's certified and tested. No changes and no new devices have been installed that we know of (or they will admit too)

*Note: Had the IT professional change the port on the Crisco last night before he went home...have had 8 bad calls this AM as of noon !!

...bob...

Could there possibly be a speed or duplex mismatch between the Allworx and the switch port? Maybe auto negotiation is set on one side and speed/duplex is hard coded on the other. Maybe auto negotiation has decided on half-duplex. It might be worth a go to hard code the speed and duplex on both the switch port and the system. Also is the patch cord solid. Use a factory patch cord if you are not already. From bitter experience, I have spent hours chasing geese on the LAN when the problem was right there in front of me...

Now that might be something to look at Meyery...if it's set in the switch to auto negotiate and under heavy traffic going to half duplex mode between the allworx and the switch..could cause a problem for me. I will look into Mr. Crisco and make sure it's set "hard code" for full duplex on the switch port.
Thanks for the tip..:-)

...bob...

I would second Meyery's comments.

I have seen that happen on many AP's and they can cause all kinds of problems.

So it makes sense that it could also happen in the switch.

Not familiar with that VoIP platform, but most don't like to see CDP or STP frames. While your switch vendor is looking at the duplex settings, might look into having them disable CDP and STP on the ports connected to the VoIP endpoints and/or call manager. They can also look at the switchports and see if they are negotiated at the proper speed/duplex as well.

Will check that also...all ports are locked down to 100 for auto-neg..which didn't help and full duplex. Crisco guy isn't much help ! Keeps trying to tell me it has to be the Allworx, I played him the .wav from the packet capture that shows clean audio at the lan port going to the network (interior) and he just shakes his head. ( I could hear ratteling noises)..So I will go over today and play some more.

...bob...

How is all of the other traffic? It could be one PC with a virus flooding the network.