Some VoIP calls being blocked | CNET News.com
Cnet.com has reported that some users are having issue receiving inbound calls. This has once again raised the issue of whether or not cable broadband companies are blocking VoIP calls.
I discussed the potential for network service providers to block VoIP traffic in my Vonage Outage Part 2 blog entry. Damn hypercompetive bastards!
A TMC VoIP Forum poster also commented on not being able to receive inbound calls, as seen in the thread titled "AT&T Call Vantage Sucks"
According to Cnet, AT&T is using a non-standard VoIP port - port 69 to be precise. Most VoIP providers use the standard SIP port - 5060. Apparently, port 69 was used by the MSBlast virus, so many ISPs are now filtering this port.
When will AT&T learn? Stick with the standards and don't go "all proprietary on us" and you'll be all right...