5550 intermitant bad audio

[LoopyLou]

Having problem with a 5550 console. Customer has a number of 3300's in three different cities. All sites in a cluster with IP trunks between. Site A and B have 5550 IP consoles. If a user ( TDM on an SX2000 or IP on a MSDN connected 3300 ) at site C calls either of the 5550 consoles they find intermitantly that the console operator hear broken up audio from the user at site C. The site C user hears no problems. Site A has two consoles and it happens on both so that eliminates hardware ( although we replaced one keypad just to be sure ). User at site C can call users at Site A or B without any problems. If console operator at site A transfered one of these trouble calls to a nearby IP set and trouble cleared.

Am confused.

Internal callers at site A or B have no trouble talking to their local console operator. Site A users can call site B console with no issues ( and visa versa ). Site A and B users can call console at site C with no issues ( although still a TDM console on SX2000 ).

Not sure how to proceed.

 

[kwbMitel]

I have had issues when the 5550 console is being used for other applications. Specifically remote desktop seems to cause speech issues. Once the 5550's were dedicated my site problems cleared.

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Occam's Razor - All things being equal, the simplest solution is the right one.

 

[LoopyLou]

Installed a second console with no applications. Same thing. Captured wireshark traces of the bad audio by mirroring the console port and once they were converted to audio format they were clear i.e played the two parts of the conversation and could hear the console say you are breaking up but the incoming stream was fine. So with all this it looks as up to the layer 2 switch port the audio is fine. Now need to check between layer 2 port and console.

Thanks for your suggestion by the way.

 

[mitelmitel]

What headsets are they using?

If plantronics then are they Polaris [no amp box], and do they have the mitel compatible lead that plugs into the keypad.

 

[slapin]

Any de-tanglers?

 

[LoopyLou]

No headsets or detanglers. We have a console that is used by switchboard and have installed a second console. Both get the problem. Moving to the console directly on to the second NIC of the MXe is no improvement. Used a different PC for software, no fix. Removed PC from back of keypad no fix.

 

[IrwinMFletcher]

Check the jitter on the network at the 5550 consoles end.

Remember/note that when you listen to the audio through Wireshark it doesn't take jitter into account, it just takes the data out of the packets after the fact. It only helps to confirm that there weren't any lost packets, not that they all arrived at the appropriate time.

I've never looked, maybe Wireshark has statistics for jitter?

 

[IrwinMFletcher]

Check that....you can in Wireshark.

Capture a stream, decode as RTP, while selected on a packet within that stream...then Statistics->RTP->Stream Analysis

Check the Jitter column.

 

[LoopyLou]

Yes we found significant jitter using the statistics analysis. Problem definately network related.

 

[IrwinMFletcher]

Good to hear. Choppy audio is almost always caused by the network. The hard part is isolating the component....