[asterisk-users] No DTMF on Sip Trunk?

[Eric Wieling]

No, it is not the same thing.  An IAX2 Trunk is a version of IAX2 that 
puts audio from multiple calls between the same two servers into a 
single UDP packet.  Fewer packets need to be sent so you use the 
bandwidth much more efficiency because you don't have the packet header 
overhead.

SIP does nothing similar.

Noah Miller wrote:
>> For ABE support you really should contact Digium.  BTW, there is no such
>>  thing as a "sip trunk".  It's a sip peer or connection or account.
> 
> <shrug> Semantics.  IAX connections between two asterisk boxes are
> often called IAX trunks.  This is the same thing in SIP
> flavor.</shrug>
> 
> Also, no offense against Digium support, but the list actually
> responds more quickly at this point.  I think the Digium support staff
> are in a situation of high demand and short staffing.