[Asterisk-Users] need help troubleshooting clipping and garbled VOIP calls

[Thomas Kenyon]

Martin Joseph wrote:
>
> On Jun 29, 2006, at 2:43 PM, T. Shaw wrote:
>
>> thanks for all the responses. I feared that it might be a bandwidth
>> issue. We have a (supposedly) business DSL line that is 1.5M - 3M
>> down/ 512k up.  might have to bump that up to a higher grade.
>
> If you are actually getting what you describe above you should have no
> need to upgrade in order to support 3 or 4 simultaneous calls...  I
> have only 384K bit's upstream on my home DSL and that's fine for 2
> uLaw calls. If you switch to GSM or G729 that should allow for even
> greater simultaneous call volume...
>
Accorging to the calculator on asterisk-guru (which I know isn't
perfect), you should be able to manage at least 30 calls with trunked
IAX and G.729.
>>
>> I did take your suggestion and contact my VOIP provider. They
>> suggested to two things:
>> 1) Use SIP to trunk with them instead of IAX ( they said that lots of
>> people complain about the conenction with IAX, but when they use SIP
>> the issues get better)
>>
> ?  This sounds like they have an issue.
With (presumably) a different provider, I seem to be getting a similar

problem, at home (even with the same accounts) IAX-in and IAX-out causes
no problems, with G.729, whereas on site IAX-in and IAX-out calls have
clipping and buzzing, with same handsets, same codec only differences
being that on site there is a timing source (TDM400) and the IAX
channels are trunked.

SIP-in doesn't seem to cause the same problems on-site.