[Asterisk-Dev] Re: 802.11b a contraindication?

[Chris Wilson]

Hi James,

> Chris> What sort of statistics do you get over long periods? High
> Chris> packet loss?  (>1%) High jitter (>1ms)? Have you tried IAX2
> Chris> with jitter buffer over the link, instead of SIP, and if so did
> Chris> it help?
> 
> It was too unuseable to do anything at all.  But I only have the
> ata186 and the laptop on that lan (at least that can do voip) so
> testing iax2 is not possible for now.

What about ping statistics, did you manage to capture those?

> I got the studdering effect.  At least from the notebook to the ata;
> I cannot say how it was in the other dir...

That's interesting, as Cisco's 7940/60 phones are very good at coping with
packet loss and jitter, I'd assumed that ATA-186s were too. What software 
were you running on the laptop? Would be interesting to know if 
ATA->laptop was good but laptop->ATA was poor, or they were both poor.

> It was as if either every other packet or so were dropped or as if
> every packet were truncated.  

Well, they couldn't be truncated, but they might well be lost or arriving 
with a lot of jitter.

What AP are you using, and what card in the laptop?

> I am using 100baseT now for the laptop's link and can do near-toll
> quality calls (using iax2/ilbc over the v90) at night and almost
> as good during the day.  (I've also tried G732.1 from the ata
> tunneled over iax between my *s and over sip to a remote harware
> gateway; that also works well.)

Nice to know, but not surprising.

I would really appreciate some more discussion on this list of how to get 
good audio performance over wireless links. I've even considered writing a 
special proxy to send all UDP packets N times to eliminate packet loss, 
and buffer them to eliminate jitter.

Cheers, Chris.
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