IP over VoIP, Anyone?

Having seen someone actually using IP-over-DNS in a pub in the centre of Brussels at FOSDEM, could the next move be IP over VoIP?

UK Wi-Fi hotspot users are being offered free Skype calls. “Broadreach hopes that after making free Voice over Wi-Fi calls consumers will be more likely to pay to check their email or surf the web at its hot spots.”

3 thoughts on “IP over VoIP, Anyone?

  1. Interesting.

    However, in my daytime-job (major telecomunciation company), we’re already using “session border gateways”, which are preventing all kinds of abuse. You might consider it a kind of firewall (also NAT functionality), but one that it also a SIP proxy, so it can examine not just the IP-packets, but also try to understand the contents of the message. Skype might (or should) be using similar methods.

    A border gateway can even be used for QoS, to make sure you can only use the bandwith that you’ve paid for. A common fraud is to negociate a 9.6KB/sec connection (or have a subscription that only allows that) ; and then start a high-bandwidth call (f.i. 1MB/sec video-phone). Most networks don’t have any protection against that. It’s ridulous easy to do that if you have access to an opensource client. Or if you can modify the firmware of a phone. I’ve demonstrated this severl times. There’s a VERY large VoIP provider in the States that is supposedly not supporting voice-phones (negociation is refused), but I’ve shown that it can be done anyway, using a 4MBps television stream (yes, watching TV over your VoIP phone). They had no QoS checks at all.

    Note that offering free VoIP service isn’t exactly a new idea – I’ve also heard of phones in shopping malls that can be used completely free. The shopping mall can use a VoIP network to limit the costs. Even if you would have to pay Skype, Vonage or a similar service, it will be a lot cheaper than a real POTS call.