Real World Computing

Last month I described my first steps into the world of VoIP network switching. My old analog switch in the lab had given up the ghost and it was time for a change - but I simply couldn't bring myself to pay lots of money for another analog switch, even one that claimed to have computer integration. It was time to bite the bullet and go for a fully digital, VoIP-based solution. I explained how I searched for a software-based Windows Server VoIP solution and decided on the 3CX server from www.3cx.com. I also purchased some IP phone handsets from Grandstream, together with a hardware VoIP gateway (also from Grandstream) that enabled me to connect up to my four existing analogue phone lines.

After last month's episode I had all the software installed, some internal phones up and running and one phone line working, but this only after some serious head-scratching - the documentation provided was minimal at best so I was almost wholly reliant on the excellent hand-holding from the 3CX software. Each phone and gateway has its own built-in web server, which sounds like a good idea until you realise that there are a thousand and one things to fiddle with inside a phone.

I was actually quite confident that I was entering the home stretch, but this is what the ancients would have called "tempting fate" and my next missteps showed how charmingly naïve I was being. Although the problem wasn't really consistent, I was clearly having some sort of trouble from the Grandstream gateway: calls would go out on one line but be reported on another, or would come in on line 1 but say they were on line 2, and so on. If you're trying to work out how your incoming calls are being routed, then this sort of front-end mess up is guaranteed to drive you nuts.

In addition, the little (and rather cute) Grandstream interface boxes I'd bought to enable hookup of traditional analog phones were giving me grief: they simply would not ring the phone on an incoming call. This was easy enough to fix: it seems RJ11-to-phone plug adapters are available either in a standard form, which is what I'd bought, or with an added ringing circuit capacitor built in. I should have guessed this from the way that master sockets work, but I was kind of expecting any adapter plug to allow ringing. Finding ring-supporting adapters wasn't easy, but a trip to Maplin in Cambridge sorted the problem.

Some experiments with the cables connecting the master sockets to the Grandstream VoIP gateway demonstrated that these brand-new cables were in fact faulty. I should point out in fairness that these didn't come with the gateway itself but were cables I had ready for the job: chucking them in the bin and getting some more fixed that problem. But things were still far from right, and I really wasn't ready to pull the plug on the old switch and make a wholesale move over to the VoIP system.

At this point I was more than happy with the 3CX software, which was proving to be the best part of the whole solution. You may recall I was running on the free downloadable version, which comes with no support other than a decent peer-supported forum. But it was becoming clear that I really ought to buy the small business licence and get the support package too, so I contacted Zen Software and talked to the ever-helpful Emmet Doyle about my options. I then waved my credit card to the tune of just over a grand, which covered use of the software with support and version upgrades till late 2010.

Continued....