Actually, the To and From headers may be different in the case of third-party registration. But in the normal case, the To and From headers are somewhat redundant.
I suppose the protocol designers could've picked just the To header and said the From header wasn't required, but that would've made the REGISTER method inconsistent with every other SIP method. Or, they could've said the From header had to be present but is to be ignored by the registrar. Instead, they defined the To header as the AOR to be stored in the address binding and the From header to be the AOR of the entity issuing the registration. It was as reasonable a choice as any other, and had the added benefits of making the REGISTER method consistent with other methods, and being consistent for first-party and third-party registrations. Anyway ... that's always been my take on it. 'Course, I didn't participate in the protocol design, so I could be *way* off base :) - g On 2/20/07, Thirumal Margabandhu <[EMAIL PROTECTED]> wrote: > Hi, > > While SIP registrar to register that time the From and To user name > filed will be same. What could be a reason for that. Anyone can answer for > this.. > > > > Thanks & Regards, > Thirumal Margabandhu > > ARICENT, > Off: +91(44)- 24330550 - Extn: 341 > Nandanam, Chennai. > > *********************** Aricent-Unclassified *********************** > "DISCLAIMER: This message is proprietary to Aricent and is intended solely > for the use of > the individual to whom it is addressed. It may contain privileged or > confidential information and should not be > circulated or used for any purpose other than for what it is intended. If you > have received this message in error, > please notify the originator immediately. If you are not the intended > recipient, you are notified that you are strictly > prohibited from using, copying, altering, or disclosing the contents of this > message. Aricent accepts no responsibility for > loss or damage arising from the use of the information transmitted by this > email including damage from virus." > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > -- Gary Cote www.awardsolutions.com _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
