Jeremey's Weblog

Ruby, Rails, Asterisk, RealTime...

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The Big VoIP Post

I've been playing with Asterisk and VoIP and WiFi phones and all kinds of toys recently, and it's time to blab about some of my experiences. First off, Asterisk is unbelievably cool. Some people say it's a big hack, and yes it is in some sense, but it's a big hack that works fabulously and does lots of cool stuff. Compared to the non-big-hack tools out there which suck badly and do nothing. It's a big hack in the same way that Linux or Apache were (are?) big hacks. They work. They give you tools to kick butt and hang yourself at the same time. Anyway...

So here's my current setup... I have an Asterisk box (just vanilla I-installed-it-myself-from-source Asterisk, on FC5), a Linksys/Sipura SPA3102 ATA (analog telephone adapter), a SIP trunk to another Asterisk (test box at work), one analog telephone (nice Sony two-line model from a few years ago), and two Nokia E-series phones. The Sipura provides an FXS port for my Sony analog phone and an FXO to plug the whole rig into our PSTN line. The Sony phone and the two Nokia phones each have extensions, and thus can dial each other.

When a call comes in from outside my Asterisk (either SIP or PSTN, though technically incoming PSTN calls are also SIP because I'm using the Sipura instead of a card in the box), all of my phones (the Sony and the two Nokias) ring at once and I can answer the call anywhere (this is pretty sweet, FYI). Unanswered incoming calls will transfer over to voice mail in the near future... right now they just get answered by an automated message saying that no-one is available. I have my dial plan (think routing, but for phone calls) set up to route work calls (PSTN or SIP) over to the test box in the office, and all other PSTN calls will go out the FXO port on the Sipura.

General thoughts on all of this:

• Asterisk really works and installing it by hand from scratch is very easy. If you're going all-SIP (or SIP and IAX) and you're using an external ATA, it's extremely straightforward to get a working configuration. You do have to edit config files, but they're simple. I'm not sure what Trixbox and AsteriskNOW really buy you if you want to be able to tinker.
• The Linksys/Sipura SPA3102 is the most frustrating device I've ever used, but it is also the most powerful little ATA box you can imagine. There are literally hundreds of knobs on this thing. But, getting it on the network and happy involved pulling hair out. But I could do it again in a snap, it's just that all the quirks and behaviors are totally undocumented (that and the IVR config system doesn't work at all). I'll put up a HOWTO or something. The SPA3000 might be a better bet if you can find one, unless you need the router functions of the 3102. A non-router variety would've saved me hours.
• The Nokia E-series phones (E61 and E70) work great. They make great wireless VoIP phones and using a converged handset (I have a SIM in the E70) is a joy, really. There are some little things that could improve usability, but mostly it's really there.
• Voice quality is very good. Especially on my analog phone, very nice.
• The POWAH! The power Asterisk gives you is amazing. Your phone system is totally yours, you control it, completely. Knock yourself out.

If you've been thinking about installing Asterisk, go for it. It's fun. I got WiFi to cellular call transfer working today (i.e. I get a VoIP call on my cell phone, now I want to leave the house, so I hit ## and it transfers the call to my cellular number by originating a PSTN call). My next project will be a module, I think. I have some ideas.... muahahahaha.

Technorati Tags: asterisk, nokia, voip