[asterisk-users] Dropouts and echo

[Tom Lanyon]

Hi all,

Can I ask that you please keep my personal address in the To: or CC:  
in this thread as for some reason I'm only getting half of the list  
emails coming through, and they're not showing up on the digium  
pipermail archive either. The list archive on http://marc.info seems  
to have the whole thread though.

> Have you tried changing the RTP packet size on the phones from
> .30(default I believe) to .20?

The RTP packet size is currently "0.030" which is the default (I  
wasn't aware we could change it). Would changing to 0.020 help?

> Turn OFF CDP on the phones.

The phones don't support CDP as far as I can find; I know Linksys is  
a subdivision of Cisco, but these phones are actually made by Sipura.

> As for Echo Canceling, that is the job of the device that
> does VoIP/PSTN gateway functions.

As mentioned before, this is SIP <-> SIP, so the echo isn't  
introduced by the PSTN. I'll keep experimenting with volume levels  
and environmental issues to try and fix the echo.

> What kind of switch are you connecting the phones to? I've seen that
> behaviour with cheap Repotec switches (24+2Gigabit). Just replacing it
> with a different one fixed the problem.

The switch is indeed a poor quality one. My next step is to replace  
it with something decent and see if it helps. I wasn't sure whether  
this could be the cause so it's good to have your input.

Thanks,
Tom