Re: [Serusers] Re: rewrite the FROM part of SIP INVITE

Ok, I've written this before, but it's important and worth another try. First of all some clarifications: - From and To have nothing to do with routing - The requirement to not touch From and To has nothing to do with SER implementation - The tags in From and To together with Call-Id form a dialog and is important for matching SIP messages in a transaction (ex. an INVITE - OK - ACK sequence) and a dialog (ex. later reINVITEs, BYE etc) http://www.tech-invite.com/Ti-sip-abnf-hf.html#from Thus, in order to be RFC3261 compliant, you need to: 1. NOT touch the tags in From and To 2. NOT touch the remainder of From and To If you break #1, you mess up transaction and dialog matching and pretty much everything breaks. If you break #2, you violate the requirement to be backwards compatible. That being said, if ALL your UAs and gateways support and use RFC3261, changing From and To names/uris (while leaving tags) will probably work, but as all subsequent SIP related IETF documents and implementation try to be RFC3261 compliant, it is assumed that From and To are only changed two places: a. In the UAs b. In a B2BUA, i.e. a server that terminates a dialog with UA1 and creates another one with UA2 and thus is a go-between New SEMS can be used for b. So, regardless of using uac module or subst for replacing From/To, you will be MUCH better off if you follow the intentions of the RFCs, i.e. change the From/To in the UAs through the provisioning systems you use. Having lots of non-compliant SER installations is a recipe for trouble in the future. Note that there is an exception to the anonymization of a call. I tried to find the reference, but I couldn't find it. Does somebody sit on the reference? I hope that was clarifying. g-) Ricardo Carvalho wrote: