On Apr 28, 2007, at 4:25 PM, Juha Heinanen wrote: > enterprises (at least smaller ones) don't run their own proxies. they > buy the service hosted and the service provider has no idea where the > individual phones are.
In some major deployments, the data suggest otherwise: In two US-Baby- Bell's hosted VoIP system, 100% of their customers had a SIP B2BUA at every customer office. Ditto for another major vendor reselling hosted VoIP service to Baby Bells. The box handles NAT traversal among other functions. So, in numerous cases, there is a SIP box between the SIP phone and the Service Provider. In many networks, including those with WiFi phones, the UAC can be compelled to register only through that B2BUA. So there's real hope that inserting the location data at relatively few points can get this deployed on the calling-party side very rapidly. > especially now when, for example, nokia > enterprise phones allow you to make calls over 3G or WLANs everywhere. This is both a location-sensing & policy enforcement problem: (a) If the location can be sensed by the enterprise operating a proxy/ B2BUA, then a proxy between the UA and the PSAP can insert the location. (b) If the location can be sensed by the UA, then it can insert its own location. (c) Else, if no location is provided to the service provider, an SP responsible for properly delivering emergency calls would refuse to let a device register. Mark _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
