Hi Richard, Its noting like CANCEL cannot be send to a re-invite. If the UAS has not send 200 (or any final response) CANCEL can be send.
3261 does not mention that a re-invite MUST not have CANCEL. HTH, Sreeram. -----Original Message----- From: Richard Wu [mailto:[EMAIL PROTECTED] Sent: Tuesday, November 20, 2007 1:24 PM To: Sreeram Kanumuri (WT01 - TES-Mobility & Carrier Infrastructure) Cc: [EMAIL PROTECTED]; sip-implementors@lists.cs.columbia.edu Subject: Re: [Sip-implementors] To Tag in CANCEL Hi, I think we cannot cancel re-invite according to 3261. It can only CANCEL initial INVITE. Richard [EMAIL PROTECTED] wrote: > Hi Joegen, > > >>> I have also seen UAS silently discarding CANCELs without to-tag if >>> it >>> > comes in early > >>> dialog state. >>> > This is wrong because the spec says that CANCEL MUST have all the > parameters identical to those being cancelling including tags. > > The only case I can see where there is a To-tag in CANCEL is : > In a re-Invite request having the to-tag,the CANCEL MUST also have a > to-tag. > > HTH, > Sreeram. > > > ---- > Sreeram Kanumuri > [EMAIL PROTECTED] > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: Tuesday, November 20, 2007 11:54 AM > To: sip-implementors@lists.cs.columbia.edu > Subject: [Sip-implementors] To Tag in CANCEL > > Hi, > > As per 9.1 Client Behavior of RFC 3261 > > The following procedures are used to construct a CANCEL request. The > Request-URI, Call-ID, To, the numeric part of CSeq, and From header > fields in the CANCEL request MUST be identical to those in the > request being cancelled, including tags. > > If my understanding is correct, even if the INVITE being cancelled has > already been responded to by a 1xx with a to-tag, the CANCEL will have > no to tag. However, I have seen implementations that send a CANCEL > with a to-tag if the call is already in early dialog state. I have > also seen UAS silently discarding CANCELs without to-tag if it comes in early > dialog state. This makes me doubt my original understanding of the > RFC. Can anyone shed some light? > > Joegen > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > > The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. > > WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. > > www.wipro.com > > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This message (including any attachments) is for the named addressee(s)'s use only. It may contain sensitive, confidential, private proprietary or legally privileged information intended for a specific individual and purpose, and is protected by law. If you are not the intended recipient, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. Any use, disclosure, copying, or distribution of this message and/or any attachments is strictly prohibited. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
