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

[Sean Darcy]

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?

"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?

I ask all this because Amazon EC2 uses a firewall that doesn't have a 
connection state. All incoming ports are blocked unless they are 
explicitly opened. Just having a packet go out to an ip address and 
port, doesn't open the source port.

But if iax is always and only using 4569 to send and receive, I don't 
have to worry about opening any other ports.

Thanks,

sean