The expected has happened: LECs (Local Exchange Carriers) started to block Vonage (or SIP in general) to protect their telephony services. (via Slashdot).

What was surprisingly is how stupidly they did this – they could just do a bit of trottling, limited the bandwidth, drop a few packets now and then, and it would take a long time before someone figure it out while in the meantime, people will think how bad the Vonage and SIP services sux and will just stay-put. But no, they go ahead and block the port totally.

And thank God for that. Now that Vonage has filed a complaint with FCC and hopefully this will set a precedence to all those who wish to try this block or trottling trick.

This is also one of the reasons why I am anti-port-25-blocking as a solution for antispam. Blocking port 25 is a quickfix but would destory the end-to-end connectivity – it is similar to blacklisting except you are blacklisting ports. Most importantly of all, the same equipments that does port 25 port blocking (and the fact they have confidence now that it will work properly) will allow them to do port 5060.