[Asterisk-Users] iax or sip

[Chris A. Icide]

Randy,

On 01:11 PM 7/5/2004, Randy Bush wrote:
 >iax uses udp and traverses nats.  neither of these seems useful to
 >me.  i loathe nats, and udp is not well-behaved in the sense of
 >congestion avoidance.

SIP and H323 use in NAT'd environments is problematic.  IAX provides 
another solution to the issue for Asterisk administrators.  If you don't 
use a NAT, then you can ignore this feature of IAX.



 >
 >trunking will save some bytes in flight iff one has four or more
 >streams moving between two pbxes.  but who would want to have the
 >pbxes in the data stream anyway?  reinvite rules, especially in a
 >geographically distributed use scenario.

There are many reasons to have an Asterisk box in a stream:

1. Control a call, (maybe you want to do some ACL type filtering, maybe you 
want to keep track of usage, maybe you just to be in control...)
2. Provide features (access to PSTN, conference capability, music on hold, 
call parking, agents and queues.....  the list goes on and on)
3. Endpoints (User Agents) MAY not be able to send data streams to each 
other directly (firewalls or nats in the middle)

And depending upon your view of things (your view might be different than 
the view of the IT/communications administrator of a large company), using 
IAX in a geographically distributed use scenario might very well be exactly 
what you want (use over an encrypted vpn link, etc.)

 >
 >now, i could see a network of iaxen if there was some way to
 >negotiate call routing with costs etc.  but trip looks a bit ugly
 >and kinda far away.  and it certainly is not part of current play.
 >
 >what am i missing here?

Nothing, really.  If you don't need IAX, and don't particularly like any of 
the features of it, then don't use it.  At this time, if you don't have 
NAT's to deal with (or you've already convinced your signalling and media 
protocols to deal with them), and you don't have a need to force the 
streams and signalling through your asterisk systems, then 'noload => 
chan_iax.so' to your hearts content!

-Chris