asterisk users - May 2005 - Recommended Network Latency

I'm planning on setting up some remote agents and before doing so, I  
did some simple PING tests to measure latency. The average latency I  
got was 250ms. Does anyone have experience in terms of quality of  
calls when there is such high latency? Can anyone comment?

Thanks,
Waldo

Waldo Rubinstein wrote:
> 
> I'm planning on setting up some remote agents and before doing so, I  
> did some simple PING tests to measure latency. The average latency I  
> got was 250ms. Does anyone have experience in terms of quality of  calls 
> when there is such high latency? Can anyone comment?
> 
Latency isn't the issue - you could happily carry on a call over a 
2000ms latency.. satellite links can introduce this easily.

Your problem is jitter (ping stability).  Some software will calculate 
this for you - eg. mtr gives the standard deviation for its ping history 
(mine hovers around the 0.4 mark over 12 hops which is really stable AFAIK).

You can reduce jitter using good QoS, but it's better to have it as low 
as possible to start with.

Tony

On Fri, 27 May 2005, Waldo Rubinstein wrote:
> 
> I'm planning on setting up some remote agents and before doing so, I  
> did some simple PING tests to measure latency. The average latency I  
> got was 250ms. Does anyone have experience in terms of quality of  
> calls when there is such high latency? Can anyone comment?

It will be fine.  Here's my worst two:

Name/Username    Host                 Mask             Port      Status    
9118/9118        61.88.37.138    (S)  255.255.255.255  4569      OK (512 ms)
whitmar/whitmar  203.221.206.187 (D)  255.255.255.255  4569      OK (430 ms)


Both Australia from South Africa (2/3rds of the way around the world - 
routing goes the long way around).  The result is inevitably rather long 
delay on the audio; but people adapt to that.

Steve

Hi Waldo.

Don't worry about it.  We have 13 sites scattered evenly around the 
globe, latency up to 700 ms.  This is of course noticeable, but I found 
that for most cases we get better quality than using PSTN between our 
sites, reason probably being that Telcos are often using low-quality 
VOIP links, reselling it as PSTN.

Our worst case is China, where packet loss is 10% - 30%, still we can 
easily maintain conversations over that link.

Hope this helps.

Regards,

Maron Kristofersson

Waldo Rubinstein wrote:
> 
> I'm planning on setting up some remote agents and before doing so, I  
> did some simple PING tests to measure latency. The average latency I  
> got was 250ms. Does anyone have experience in terms of quality of  calls 
> when there is such high latency? Can anyone comment?
> 
> Thanks,
> Waldo
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