[Asterisk-Users] Porting a phone number to a voip provider

[Matthew]

Rich Adamson wrote:
> Just an FYI... not all cell numbers are portable.

Do you have any more information on this?  I read somewhere that 
sometimes you can port a number to a VoIP provider but not be able to 
port it back to the PSTN because not all PSTN providers will take 
numbers from VoIP providers.  Is this what you are talking about?

Matt