T-Mobile Releases New Card, Outlaws VoIP and IM

An anonymous reader writes "T-Mobile has launched a new 3G data card in the UK, and banned users from using it for VoIP or instant messaging applications." From the article: "Lock cast doubt on the sustainable viability of a mobile operator banning VoIP from its network. 'I think that eventually, if there's customer demand for this, it will happen," Lock said. "Other organizations will come along allowing VoIP. Who do you think is going to win?'"

Comments

Please remember

[saikou]

1. It's T-Mobile UK, not T-Mobile USA. Not yet, anyways. Web browsing with 3G speeds for 20 pounds a month? Goodluck finding that :) (eventually it probably will be available from T-Mobile USA but not yet)
2. It's a business plan. If you look at a regular "non-professional" plan then you'll notice that even more restrictive full fineprint says:

Minimum term contact and credit check applies. Compatible handset required. Fair use policy applies: Relax + web 'n' walk and Flext + web 'n' walk price plans provide unlimited internet surfing on mobile handsets in the UK. To ensure a high quality of service for all our customers, they are not to be used for other activities such as (but not limited to): modem access for computers, internet based video/audio streaming services, peer to peer file sharing, internet based video download and internet based telephony. If such use is detected, notice may be given, after which network protection controls may be applied which will result in a reduced speed of transmission.

(emp. mine). Professional plan says nothing about "modem access for computers" (VPN) or downloads and such.
Given how much talking on the phone costs in UK I'd say it's very clear why they don't want to allow VOIP. Texting is not that expensive but still provides a nice revenue.

150ms is fictional / misunderstanding

[billstewart]

First of all, the 150ms recommendation was originally for in-continent calls - the standards people recognized that transoceanic calls might need to be as long as 400ms, and that's still better than satellite. Remember that the speed of light in fiber is about 8-10ms per 1000 miles, depending on how straight your fiber routes are (it's a "miles of fiber per miles of route" issue, not an attenuation issue) and just because you can theoretically get halfway around the world in 100-125 ms, doesn't mean that real cable routes will let you do that. India and New York are just far apart, and you've got to deal with it, unless you want to drill a hole through the earth's core.

Second, aside from what the _standards_ say, calls don't become "functionally useless" above 150ms - just a bit slower, and if they're much slower you might not want to use that cheap speakerphone. Back in the old days, when we used to walk 20 miles barefoot to the schoolhouse uphill both ways, satellite was the standard way to talk across oceans and sometimes even within the same continent, and they were ok. Not great, and sometimes annoying, but ok.

Direct-dialed calls from California to Tennessee almost certainly *are* carried on POTS, though calling-card calls to India usually aren't. POTS isn't just analog-on-copper - the call gets digitized to 64kbps PCM at your first telco office, switched through circuit-switches, and carried on T1 lines (1.5 Mbps synchronous channelized stuff). The T1s get muxed together onto fiber, of course, and the fiber's usually DWDM stuff that puts 16-64 2.5-10Gbps channels on each pair, but with the major US telco carriers, most of the calls are still old-school as far as switching goes. LA to Nashville is about 2000 road-miles, so if you get a good fiber route it should be about 20ms one-way.

That'll be changing a lot within the next 5 years - the old phone switches are becoming obsolete, and soft-switch technology is getting a lot cheaper, and it'll be the costs of switches (including parts and labor) that drives a lot of the change - fiber bandwidth is so cheap that it's cheaper to haul intra-US calls uncompressed compared to deploying telco quantities of compression equipment. Another big driver is mobile phones, since they already use a compressed-voice infrastructure.

International's a lot different - bandwidth across oceans is expensive, so it's worth paying to compress the voice, especially if you either don't use IP or use trunked compression protocols that don't need to waste 40 bytes of IP/UDP/RTP header on a 10-byte voice sample. Those 1 cent calls to Asia are doing a lot of that.