[asterisk-users] iax2: two users can't authenticate from same ip address

[Joshua Colp]

Sean Darcy wrote:
> On 09/10/2013 12:15 PM, Joshua Colp wrote:
>> Sean Darcy wrote:
>>> Maybe a different question would be helpful. Let's assume no NAT; the
>>> server is directly connected with an FQDN. Two iax devices register.
>>> Does asterisk assign them different ports?
>>
>> Asterisk does not assign ports. The IAX2 channel driver, by default,
>> binds to a single UDP port (4569). As UDP is connectionless there are no
>> connections. What you see on the console is the *source* IP address and
>> port of the packets. It's possible that the Amazon stuff is sort of
>> NATting things to do connection tracking... but that's Amazon land, so
>> no clue really.
>>
>
> Since no horse is dead enough not to take another beating:
>
> If the console is showing the *source* port of the packets. then:
>
> does the server send iax packets to that source port, or to 4569?

It sends to the source port if using the registration.

>
> "home" (which is another asterisk server) shows 4569, while the androids
> running zoiper show random ports. I assume zoiper puts the source port
> in an iax packet. But regardless of how zoiper describes its source
> port, asterisk will only send iax packets on 4569. correct?

It does not put the source port in an IAX packet. It's in the IP header 
itself, outside of IAX. Asterisk will send IAX packets *from* port 4569 
but *to* any host/port.

-- 
Joshua Colp
Digium, Inc. | Senior Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at:  www.digium.com  & www.asterisk.org