IAX2 technology

Started by darmock, March 11, 2011, 11:46:02 AM

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I would like to see support for IAX2 as well as SIP in this platform. IAX2 uses a single port for everything and has a better ability to compensate for NAT issues in router/firewalls. I currently use IAX2 to interconnect my asterisk boxes together. I feel with the addition of this the OBI family of devices would be in the position of providing one of the best "boxes" on the market. Of course there are several digital phones ou there that support IAX2 bit they don't have the flexibility of the OBI devices.

Another feature of the IAX2 protocol is the ability to encrypt the "conversation" between points. While it is not the strongest it does work and I am starting to believe that all conversations need to be encrypted as routine.

I want to take this opportunity to thank the Obi people for their great work and their support of our little project. PBX in a Flash

Best regards

Lead Developer
PBX in a Flash Project


+1 for this one.  With all the problems I've encountered over the years trying to get SIP to work through a firewall, there would definitely be situations where this could come in handy.

Although, I will also say that IAX2 isn't the ultimate solution in all cases.  I actually have a SIP trunk between two Asterisk boxes that works well in every way, but if I try to substitute it with an IAX2 trunk I get all kinds of audio issues (sounds like missing packets or something).  But the weird part is, I can run an IAX2 trunk between either of those systems and a third system and I have no problems at all.  It's only when I try to use IAX2 between those two particular systems that I have a problem.

The other issue with IAX2 is that I don't think it can do reinvites (feel free to correct me if I'm wrong about that), so all your traffic has to flow through the server.  But still, in a situation where you absolutely cannot get SIP to work because of a NAT firewall situation (particularly when you're trying to set up an adapter for a non-techie at a remote location, and they're trying to do something dumb like run the connection through two NAT routers), IAX can get the job done.

I know that Atcom devices (at least some of them) support IAX2, so it must be possible to include it in this type of device.  The only thing I would wonder is how much additional memory the code would consume, and whether the OBi devices have that much to spare (without compromising other features).

An alternative would be to include OpenVPN support (an internal OpenVPN client) - as long as you had an OpenVPN server on your Asterisk box, that would give you the single port connections through firewalls and encryption, while still using sip internally.  But that might be harder for the system administrator to set up, and I don't know which approach would use fewer resources on the device, but I suspect that IAX2 support would use less than an internal OpenVPN client (then again, that's just a wild guess on my part).
Inactive, no longer posting or responding to messages.  Goodbye and good luck.  Some of my old Obihai-related blog posts have been moved to http://tech.iprock.com - note this in NOT my blog; I have simply given the owner permission to repost some of my old stuff.


Nope IAX2 is not the ultimate solution rather a tool in a toolbox that will do the job in some cases where others won't. I like the idea of openvpn also again another tool that would make the obi a "jack of all trades"

It seems to me you are right about the reinvites.

I also use the atcom device that supports IAX. It is useful for "friends" who are technological luddites I can just send them one and they plug a phone in the power and the internet and "it just works". I believe this type of transparency is what Obihai is aiming for with the 110. I think if they can support IAX2 I will throw away my atcom devices and start sending out the 110's instead.

Of course there are a few hardphones that directly support IAX2 but not GV. I guess I am asking for the "ideal" device. Course this is just my vision.