[reSIProcate] Registrar rejects multi-registration from same ip/port source

[Hong Yu]

I'm testing reciprocate with a commercial Registar (by a leading network
gear company). If I use a single transport, it only allows one device to
be registered. Any subsequent device registration will be rejected. I
think it is a too much a restriction on their end and it's not a
behavior defined in any standard. 

Any comments on this would be greatly appreciated.

Hong