[Sip] Matching requests to server transactions

[frank.derks@philips.com]

Section 17.2.3 of version 9 of the SIP draft contains the following text:

"The request matches a transaction if the branch parameter in the request is 
equal to the one in the top Via header field of the request that created the 
transaction, the sent-by value in the top Via of the request is equal to the 
one in the request that created the transaction, and in the case of a CANCEL 
request, the method of the request that created the transaction was also 
CANCEL. This matching rule applies to both INVITE and non-INVITE transactions 
alike. "

It would seem that this text is trying to state the following:

- if a CANCEL request is received and its branch and sent-by values match 
  those for a transaction that was created because of the reception of a 
  prior CANCEL request with the same values, then the request matches the
  transaction.

- if a non-CANCEL request is received and its branch and sent-by values match 
  those for a transaction that was created because of the reception of a 
  prior non-CANCEL request (but not necessarily the same type of request!)  
  with the same values, then the request matches the transaction.

Is this a correct interpretation? If it is then I suggest re-writing the
above text to better reflect this.

Regards,

Frank