[Serusers] "stun" parameters in Contact HF

[Massimo Barletta]

Hi all,

I'm testing a new UA and I've got a Contact Header Field format in 
REGISTER msg I'm not aware of:

    REGISTER sip:/sip.mydomain.com/:5060 SIP/2.0.
    Via: SIP/2.0/UDP *0.0.0.0:0;*branch=z9hG4bK2497750963.
    From: <sip:/pstn_number/@/sip.mydomain.com/>;tag=3670695360.
    To: <sip:/pstn_number/@/sip.mydomain.com/>.
    Call-ID: 2377110845 at 192.168.1.4.
    CSeq: 1 REGISTER.
    Contact: <sip:/pstn_number/*@0.0.0.0:0;**stun=4*>.
    max-forwards: 70.
    expires: 3600.
    user-agent: oSIP/Linphone-1.1.0-IMVP.
    Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, INFO.
    Content-Length: 0.

i.e. ip:port is no longer in Contact or Via Header Fields and a stun=4 
parameter is specified in Contact HF

Have you got any clue on RFC reference for this behaviour?
How can I handle this on SER?

(SER fills location table as follows:

    username: /pstn_number/
    domain: /sip.mydomain.com/
    contact: sip:/pstn_number/@0.0.0.0:0;stun=4
    received: sip:/UA_ip_address/:5060

)

THX,

Mety