RE: NAT-PT Applicabilty for 3GPP

["Karim El-Malki (HF/EAB)" <karim.el-malki@ericsson.com>]

 > >That is not the only issue IMO.
 > >According to RFC 2766 an implementation will take incoming 
 > packets destined
 > >to PREFIX::a.b.c.d and translate them to IPv4 destination 
 > a.b.c.d. It will 
 > >also
 > >locally assign and use an ipv4 source addr/port. We don't 
 > want this behaviour
 > 
 > Can you please point out where in the NAT-PT RFC it says it 
 > should be 
 > locally assigned
 > or where it explicitly prohibits mappings installed from an 
 > external entity?

I assume your question wants to highlight the fact that RFC 2766
doesn't rule that out. OK. Still I don't see your point? If it allows
local pools, which are in fact the most likely thing people
implement, and does not specify communication with an external box
then it is not the spec we want to recommend.

My point is that if we say NAT-PT is applicable for SIP then people
will expect to read RFC 2766 and implement it. If they do that
they are likely to implement a local pool of v4 addresses and a
SIP ALG (that does SIP editing). Since SIP folks are not in favour
of SIP editing I don't think we should say that NAT-PT is applicable
to the SIP case. It is much cleaner to create a SIP specific solution
for this case that is not related to generic NAT-PT and its problems.

/Karim