Quality of Service
Cisco's Rohan May didn't quite jostle Zennstrom at the end of his speech, but you could tell he wanted to and demanded to know when Zennstrom would build a connection to SIP. He said Skype had no Quality of Service and effectively challenged Zennstrom to some kind of demonstration, Skype against SIP.
Privately Zennstrom said: "It isn't when Skype is going to be compatible with SIP, but the other way around. I wrote Skype partly because SIP was such a bad protocol. It can't tunnel through a NAT server, or firewalls."
He wasn't the only one to say this, with most people content to say it in whispers over coffee, that most versions of SIP were incompatible and that it required a re-engineering of enterprise networks to get VoIP calls through reliably.
But if that gives a potted view of the two worlds of VoIP, the personal and the enterprise, there is a third world that is the preserve of telecommunications operators only.
British Telecom coincidentally made the announcement of its future IP architecture on the last day of the conference. BT's network will go IP end-to-end, creating massive savings, and it will also begin trialing fibre to the premises, echoing recent moves made by Telcos in the US.
There will be large scale migration of voice services from 2006, the first stage in the migration pilot will involve the bypass with multi-service access nodes of the core PSTN network link between two major network nodes at Cambridge and Woolwich. An extension is planned later in London.
And if calls are packet switched instead of circuit switched throughout the network, then this will give BT and just about everyone great advantages when it comes to moving VoIP data around the country. And just what will the regulators say about a national telephone network that is really a set of servers and softswitches with IP traffic. It will certainly make for interesting times and enterprise telephony will plug more easily into the future BT network, complete as it will be by 2009, as long as that enterprise traffic is IP ready when it leaves the building.
Remember BT's telephony won't be on the Internet, it will be on a private Internet called British Telecom's network. So is VoIP a PC application as Zennstrom says, or is it a set of enterprise servers and services, as Day believes, or is it simply the telephone network? We're inclined to think it's all three.
© Copyright 2004 Faultline
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