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.

US Senate bill HR 3043 (New and Emerging Technologies 911 Improvement Act of 2008) has been passed into law and requires traditional telephone companies to make available access to 911 services for Voice over IP operators.

An article at VoIP Weblog suggest that the old telcos may have actually been blocking access to 911 for some VoIP operators. Smithonvoip is similarly aghast that 911 services which exist to provide access to emergency services could have been blocked.