nist-sip 1.2 and NAT traversal : issue with ListeningPoint sentby field

Hi,

I've been using the NIST SIP stack, and recently updated to the latest
version (note in passing, great job guys).

However, my code to deal with calls that are outbound thru a NAT'd router no
longer works.... If anyone can explain what I'm doing wrong it'd be a great
help.

Basically, I want to make calls out (send the INVITE) to destinations that
may be either on an 'internal' network, or 'public' ie outside of a NATing
router.
There is no problem for the INVITE sending (using UDP), as the destination
IP is routable in both cases. My code detects when the destination is going
via NAT, gets the public IP of the router from a config file, and:
	- adds a Via header accordingly
	- fixes up the From, Contact etc URIs (change the local IP to the external
IP)
	- ensures the RTP SDP IP is the external IP
This all worked fine until I updated to 1.2....

Now, when I send to the public network, I get:
javax.sip.TransactionUnavailableException: sentBy does not match the sentby
setting of the ListeningPoint 62.212.123.79:5060
        at
gov.nist.javax.sip.SipProviderImpl.getNewClientTransaction(SipProviderImpl.j
ava:304)
	... etc
My external IP (in the Via, From, Contact etc) is 62.212.123.79 and my local
IP (to which the ListeningPoint is bound) would have been 192.168.0.167
(local server).

So, when I create the ListeningPoint at initialisation of the server
process, I tried setting the sendby using setSentBy() to  be the external
IP...

Now, it works when I send to an external destination, but not when I send to
an internal one!

Is there a way to stop the ListeningPoint checking its sentby field against
my Via, From etc headers? Or is my basic method (fixing up the headers
myself) wrong, and I should do it another way? Or do I have to use 2
SipProvider instances, one for internal calls (sentby=192.168.0.167:5060)
and one for externals (sentby=62.212.123.79:5060)? (this is not my preferred
solution....)

All ideas gratefully received....

Brian

[ Brian Wyld : Eloquant SA    ]
[ Directeur technique         ]
[ brian.wyld at eloquant.com  ]
[ tel: +33 476 77 69 54       ]
[ mob: +33 609 62 10 87       ]
[ fax: +33 476 77 40 65       ]