It is a challenge these days to get number portability sorted out. In fact in this case it was easier to go back to the PSTN than to use VoIP and try to port your number. See Tom’s blog for details.
Number portability seems to still be a major problem in the world of VoIP and one of the first stories about the topic was by yours truly. In this article I mentioned I am switching from Vonage to AT&T CallVantage because I couldn’t port my number.
Now it seems that AT&T CallVantage is the poor stepchild of AT&T — who knows if this service will even last. There is little or no branding or messaging for this service. It will be interesting to see how CallVantage does in the next few years.