Liaison statement
Reply to the LS to IETF for clarification on RFC 4006 for Diameter base protocol

The IETF DIME WG thanks the 3GPP SA5 WG for their LS and query regarding the
IETF RFC 4006 (https://datatracker.ietf.org/liaison/1470/).

The IETF DIME WG has discussed both options raised in the LS from 3GPP SA5:

1) Is IETF RFC 4006 planned to be updated in order to rely on IETF RFC 6733 as
the new Diameter Base protocol?

2) If not, are there any recommendations from IETF on how to address the
implicit reference to IETF RFC 3588 as Diameter Base Protocol for 3GPP SA5
Diameter Online charging through use of IETF RFC 4006?

and the decision was made to update of the IETF RFC 4006 as per the option 1).

The aim of this update is to:
- align the Diameter Credit-Control application specification with the IETF RFC
6733, - fix existing known issues in the current specification, - comply with
the recommendations given in the IETF RFC 7423 on the design of Diameter
application.

The time line for the completion of the RFC 4006 update is set to November 2017.

As a reminder, the IETF RFC 6733 does not define a new Diameter base protocol
but is a new version of the specification defining the Diameter base protocol.
The IETF RFC 3588 is obsoleted by the IETF RFC 6733, as defined in the IETF RFC
2223:

   Obsoleted-by

      To be used to refer to the newer document(s) that replaces the
      older document.

In the present case, any document using the IETF RFC 3588 as reference for the
Diameter base protocol should be updated to refer to the new IETF RFC 6733.
Therefore, as a general guideline, the IETF DIME WG recommends 3GPP WGs to
follow this recommendation in their specifications when applicable. The same
recommendation will apply for the revision of the IETF RFC 4006 when published
by the IETF as for any new RFC obsoleting an old RFC.