I got this idea in my head that there must be a software SIP phone available for Mac OS X by now… this is the story of my adventure.

It started innocently enough.

I pulled up ohphoneX, got frustrated over connectivity to the H.323 gatekeeper at work, and decided it was time to do a Google search to see if SIP had made any progress in the last year. And, surprisingly, I found a reference to a Mac OS X client on the second search.

Enter X-Lite from Xten Networks. Amazingly, it’s free! The documentation pointed me at a number of SIP service providers, several of which have a common theme: free PC-to-PC calling. So, next I created an account on FreeWorld Dialup (FWD) and configured X-Lite. The instructions were straightforward, something this rookie SIP user really appreciated.

Finally, I had to make sure that ports 5060 and 16384-16391 are allowed in through the firewall. My Asanté firewall allows me to set those as inbound ports that dynamically open up if there’s an established session on port 5060. (This is very similar to the firewall configuration used for iChat AV, by the way.)

So, with everything set up, I started to test the system.

FWD provides an echo server as a way to get a feel for latency. At first I was horrified – the delay to hear my own voice was about 3/4 of a second. Can you imagine talking to anyone with that kind of delay? However, I reasoned that it was on the order of half that, which might be bearable. To be honest, I would prefer if round trip was under 200 msec, but I’ll live.

About 45 minutes later my friend Herb in Calgary came back in from the garage. He had already offered to have me call him, as the company he works for these days is all about SIP, and they provided him with an IP phone gateway at home. The latency was indeed bearable, and we had a nice conversation until my microphone cut out. I noticed this a couple of other times with the test server, but I haven’t quite figured it out yet. Perhaps it won’t matter very much longer, though. There’s a new bauble showing up one of these days, or so I’m told. (I’d tell you, but blah blah blah kill blah.)

So there you have it. This should be interesting…