If one ports one's number to a different network provider, do requests to contact one at that number always get routed initially through the first network provider?
E.g. if I am initially on O2 and I transfer my number to Vodafone, when somebody calls me, does their network first reach the O2 system, and then get redirected to Vodafone?
(terribly poorly worded, I know, but I can't think how to explain it without crude diagrams)
that may happen in the short term but the need for a PAC "porting authorisation code" means that the other network .. vodafone in this example, are taking on your number full time.
Anyone calling you say, on O2 would no longer get to use their O2 to O2 free / inclusive calls as they are from the moment you "port" and your number switches over calling a Vodafone number / service.
All right, but the scenario couldn't arise where one has transferred one's number so many times that there is a spaghetti junction of network providers redirecting calls in every which way multiple times(?)