Subject: [AAA-WG]: [issue] location of Proxy-Info and Route-Record AVPs

From: Yoshihiro Ohba <[email-masked]>
Date: Tue, 21 May 2002 15:46:19 -0400

Submitter name: Yoshihiro Ohba
Submitter email address: [email-masked]
Date first submitted: May 21, 2002
Reference:
Document: base
Comment type: T
Priority: 1
Section: 8.3.1 etc.
Rationale/Explanation of issue:

In the following message format of Re-Auth-Request command described
in section 8.3.1, Proxy-Info and Route-Record AVPs, which are defined
to be optional, comes after "[ AVP ]" (this comment also applies to
other commands that define AVP(s) after "[ AVP ]"):

   Message Format

      <RAR>  ::= < Diameter Header: 258, REQ, PXY >
                 < Session-Id >
                 { Origin-Host }
                 { Origin-Realm }
                 { Destination-Realm }
                 { Destination-Host }
                 { Auth-Application-Id }
                 { Re-Auth-Request-Type }
                 [ User-Name ]
                 [ Origin-State-Id ]
               * [ AVP ]
               * [ Proxy-Info ]
               * [ Route-Record ]

But I think this definition contains the following ambiguity.

If the intention is that those AVPs are optional but to be put at the
tail of the command, they should be defined as AVPs with fixed
position like:

      <RAR>  ::= < Diameter Header: 258, REQ, PXY >
                 < Session-Id >
                 { Origin-Host }
                 { Origin-Realm }
                 { Destination-Realm }
                 { Destination-Host }
                 { Auth-Application-Id }
                 { Re-Auth-Request-Type }
                 [ User-Name ]
                 [ Origin-State-Id ]
               * [ AVP ]
               * < Proxy-Info >
               * < Route-Record >

Otherwise, if those AVPs are just optional AVPs without a special
position requirement, it would be better to define the format as:

      <RAR>  ::= < Diameter Header: 258, REQ, PXY >
                 < Session-Id >
                 { Origin-Host }
                 { Origin-Realm }
                 { Destination-Realm }
                 { Destination-Host }
                 { Auth-Application-Id }
                 { Re-Auth-Request-Type }
                 [ User-Name ]
                 [ Origin-State-Id ]
               * [ Proxy-Info ]
               * [ Route-Record ]
               * [ AVP ]

Requested change:

Needs more clarification or change the format to remove ambiguity.