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#2307 - 12/12/11 09:52 AM ShoreTel Voice system difficulties
jlast Offline


Registered: 12/09/11
Posts: 2
Loc: WI, USA
We have been battling a strange difficulty with our phone system. High jitter rates and audio loss occur without warning or reason. We have been successful in re-creating the problem and used PingPlotter to capture the data between the phone and the related T1 switch (used for the call via connected PRI). The file loaded was from a laptop to the T1 switch. We (here) have differing opinions as to where the loss is occurring. Your assistance in clarifying this is appreciated.


Attachments
10.31.254.21 DanH pc to T1k.pp2 (288 downloads)


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#2308 - 12/12/11 12:18 PM Re: ShoreTel Voice system difficulties [Re: jlast]
Pete Ness Offline



Registered: 08/30/99
Posts: 1106
Loc: Boise, Idaho
Hello.

The only "clear-cut" issue is at hop 4 here - the packet loss at 9:36am. The other latency and little bit of jitter at the prior hops doesn't seem to be showing up at hop 4 (the T1, right?), so what you're looking for is something at hop 4, or between hop 3 and hop 4. Do you have a network hub there (like a 8/16 port hub of some kind - that doesn't have any smarts)? My bet would be on failure of a power supply or the hub itself in a low-intelligence hardware piece between hop 3 and 4 (maybe as "low intelligence" as a network cable).

- Pete

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#2309 - 12/12/11 12:54 PM Re: ShoreTel Voice system difficulties [Re: Pete Ness]
jlast Offline


Registered: 12/09/11
Posts: 2
Loc: WI, USA
There is a Cisco 3560 (addr=192.168.2.30) that the T1 is connected to. We have also been able to re-create the problem using another parallel circuit with different hardware and connections.

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#2310 - 12/12/11 01:30 PM Re: ShoreTel Voice system difficulties [Re: jlast]
Pete Ness Offline



Registered: 08/30/99
Posts: 1106
Loc: Boise, Idaho
Could be a bad cable going into the T1 hardware, or something bad with the T1 hardware itself. It could also be something wrong on the other side of the T1 and it's refusing packet delivery while it retrains. I'd get your T1 supplier involved - most T1 hardware has troubleshooting tools built in to help track this down - give your provider the exact time of the problem and see what the T1 hardware logs have to say about the problem. If there is not issue visible there, it may be in the T1 device on your "edge" of it, like a bad solder connection or similar. Most providers are going to be pretty helpful with this type of thing and they'll probably drop new hardware in there.

I'm totally shooting from the hip here - I don't know anything about your hardware and only have a single failure point to go from - so forgive me if I'm barking up the wrong tree. The squirrel may be elsewhere, but the leaves are shaking on *this* tree. smile

- Pete

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