[Serusers] rewritehostport and RFC3261 compliant

Hi all, I find an issue with a problem encountered on some products. The problem only concerns on-net calls. In fact, when a SER User A calls a SER User B : - if B doesn't answer, after the tm timer : ==> t_on_failure("1") ==> setflagt(24) ==> load $ruri/username in vm_uri/usr_vm if flag is set to 24 then ==> avp_pushto $ruri s:vm_uri ==> resetflag(24) ==> add prefix Prefix("710") ==> rewritehostport(Asterisk:4060) ==> append_branch ==> t_relay_to_udp(Asterisk,4060) This is the process apply for transfer the call to the voicemail Asterisk. But, and only in this on-net case, the To-Tag change during this process, cause the failure of communication for some products. Whereas the RFC 3261 specify "... This tag will be incorporated by both endpoints into the dialog and will be included in all future requests and responses in this call ...". Thanks for your support.