[Serusers] NAT with multiple SERs

[Juha Heinanen]

Andreas Granig writes:

 > UAC-1 sends a SIP-Register to SER-1, so NAT is opened for UAC-1 <-> 
 > SER-1. But since UAC-1 doesn't send something to SER-2, NAT is never 
 > opened between UAC-1 and SER-2, which is what I meant with "no 
 > NAT-binding". Because of this SER-2 can't send a SIP-Request to UAC-1 
 > because it's blocked by the NAT-device.

yes, that indeed sounds like a problem.  when contact of uac-1 is nated
and memory only, ser-2 should use ser-1's address as source address for
requests to uac-1.  the other option might be to make ser-1 to send an
options request to uac-1 using ser-2's address in contact.

perhaps somebody else has better suggestions?

-- juha