Martin Geddes is sceptical.

I ought to explain why I’ve suddenly gone cold on VoIP.

It’s just I’ve watched my own behaviour. I’ve grown tired of the inconsistency of PC VoIP calls, and instead I’ve reverted to using landlines, mobiles and Jajah (for callback). But I’m still using IM to set up many of those calls!

The problem isn’t unique to any one client — they’re all proving unsuitable for business use with clients (which is most of my telephony needs covered).

The worst of all seems to be Skype conference calling. We probably would rate the quality as “unacceptable” for 50% of the attempts. When it’s good, it’s great. But that isn’t what I’m after.

He goes on to talk about how softphones don’t work very well.

Another problem with PCs is they’re just lousy telephones. When you hibernate Windows XP on my HP laptop, all kinds of audio settings seem to go wrong and the volume buttons stop working. Bluetooth is hopelessly unreliable, and who wants another wireless headset device to remember to charge up (and bring the charger when you travel)? Or to have to rush to fish out a headset and plug it in when a call arrives?

Before I get accused of plagiarizing the whole piece, you can read the full post.

There are a couple of issues here:

VoIP qua VoIP is really a very broad spectrum of technologies, encompassing softphones, free calling, replacing million dollar hardware PBX switches with open source software switches, and new applications. Martin’s definition for purposes of his discussion, if I read his article correctly cites two problematic applications; softphones on PCs, and conference calling on Skype.

I agree with his scepticism. My own interest in more in Asterisk/Trixbox and replacing the traditional circuit switched phone line infrastructure with packet switched calls over the internet. While I have made a couple of calls from my laptop, it seems a little bit silly to do so when I’ve got my $15.00/month cell-phone handy. So if softphones don’t work I’m personally not going to slit my throat.

But, the internet calls thing, is more problematic. Clearly, we are at the mercy of the internet when placing such calls… once your packets get outside your own local area network, they are flung out on the storm-tossed seas of the public internet. And, as we all are getting what we wished for with network neutrality, our packets are being treated like everyone else’s packets. So, your 911 call’s packets might be held up by an image of Johnny Depp, or even the whole movie.

One solution of this so far, as been “quality of service”, which is a euphemism for “prioritizing packets”. If people played nice, then, every router on the net would be smart enough to know that some packets are more equal than others, and voice and media packets in particular need to be forwarded before eMail and ftp packets. And indeed, if I’m making VoIP calls from my Trixbox while downloading those bloody updates for Windows, call quality goes down the tubes, (and this is with me, placing a single call, and downloading from a single workstation on my LAN).

The second solution, and really the only one at this point, has been to provide enough bandwidth so that whatever the exigencies of packet transfer there is enough slack in the network so that most of the voice packets will arrive, in the correct order. In buildings that use VoIP phones, the best practice is to run a separate set of 10BaseT cabling for the softphones. Mind you, this is a separate subnet from the data network that is currently in place. (Note: Someone will argue that this already in place, because we’ve got the existing two or four pair wiring in place for the telphone…)

So, is it responsible of us to suggest for a non-profit that they should:
1. Invest in new desk phones at $125.00 for each desktop location
2. Double their cable infrastructure
3. Purchase a quality of service router that at least will prioritize packets moving in and out of their own location
4. Purchase a dedicated server, with attendant UPS backup and management
5. Figure out how all this goes together.

when it may not work. Specifically, that you won’t be able to rely on 99.99% availability when placing internet calls, and you won’t be able to ensure that 99.99% of inbound calls to your internet-brokered phone lines will reach you.

when you can go to Best Buy or Amazon and get a Panasonic key phone system with six phones for $2500 or so, which you can forget about once it is installed.

I’m just asking.