Secure VoIP, an Achievable Goal
An anonymous reader writes "ITO is running a comprehensive article on VoIP security issues and how one can protect against them: "VoIP creates new ways of delivering fully-featured phone services that promise big cost savings and open the way for a whole new range of multimedia communication services. After years of 'will it, won't it' speculation and unfulfilled predictions of universal adoption, Gartner is now positioning VoIP firmly on its way to the 'plateau of productivity' on its widely-respected technology hype cycle. But questions about its security and reliability persist.""
There is a standard on how to encrypt voip already called SRTP, the problme is there is still a lot of debate on how to deal with the key exchange. MIKEY is the latest path, but most CPE vendors see it as overkill and to complex. SNOM and a few others have went with SDP Descriptions, a lightweight method, but requires TLS for signaling. Then you have guys like Sipura/Cisco who come up with a 100% propritary way of doing things that only will work with their devices.
> Nathan Stratton nathan at robotics.net http://www.robotics.net
Ah, yes the quality issue. It drives me crazy that when VoIP providers (yes, as Co-Founder of BroadVoice I was one of them) try to build services the benchmark is PSTN. They use CODECs such as G.711 and G.729 that are almost as old as I am. Believe it or not, DSP power has increased in the last 20 years, Next gen CODECs such as SPEEX can deliver great quality at low bit rates and was designed for packet networks. One other big issue is that PSTN is only about 4 kHz of bandwidth, when you take the guardbands out it is more like 400 - 3600 kHz. SPEEX, AMR-WB and others support 16 or even 32 kHz of voice bandwidth. The problme is a chicken and egg issue. CPE guys don't want to support it because there is nothing to terminate to. ALl the major VoIP guys use people like Global Crossing, BroadWing, XO, for SIP origination/termination and they use SONUS or other TGs that only G.711 or a few other CODECs. The real solution is for VoIP providers to support transcoding at the edge. That way you can use next gen CODECs on the last mile and then hand of G.711 to orig/term providers.
> Nathan Stratton nathan at robotics.net http://www.robotics.net