Comcast say they have reached a collaborative agreement with Vonage which appears to suggest that while Comcast have their own VoIP offering, they wont be blocking or degrading Vonage’s rival product.

Quite where that leaves other SIP and proprietary VoIP users on Comcast’s network is anybody’s guess.

Comcast also say they haven’t been blocking any rivals VoIP in the past either but accusations have been levelled at them.

Connection quality is critical for Voice over IP applications as you need as much of the data as possible to arrive in a timely manner. ‘Packet loss’ in a VoIP conversation can manifest itself as a degradation of quality in the call followed by the call actually breaking up and finally being dropped altogether when too few packets arrive. Delaying of data at the ISP level can cause issues where the latency of the call makes normal conversation difficult.