[asterisk-users] chan_sip sending from wrong source address when multiple interfaces are used

[Kevin P. Fleming]

On 07/12/2012 03:53 PM, Benny Amorsen wrote:

>> chan_sip does have the ability to use connect()-ed sockets for dialogs
>> now, since that is required for TCP, TLS and WebSocket support. It
>> wouldn't be a huge leap to use them for UDP as well, if that was
>> beneficial.
>
> It would be greatly appreciated :) It is low priority for the Asterisk
> project, as there are always workarounds.

I've just looked into this a bit, and I don't see how using connect() 
would actually solve the problem. If we receive a UDP datagram from a 
SIP endpoint, we could use socket() and connect() to create a socket 
specifically for sending to (and receiving from) that endpoint in the 
future, but we can't specify the source address to be used by that 
socket. The only way I know of to specify the source address for 
outbound packets is to use a raw socket and compose the IP header 
ourselves, which would be overkill.

Benny, are you aware of some other method to accomplish this?

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
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