[ANCP] Question about Multicast Status Message in draft-ietf-ancp-mc-extensions-00

[Fortune HUANG <fqhuang at huawei.com>]

Hi all,

 

I am puzzled about using Multicast Status Message for failed response in many different procedures (e.g. Delegated Bandwidth Query, Multicast Flow Query) in draft-ietf-ancp-mc-extensions-00.

 

Take the Delegated Bandwidth Query procedure in section 4.8 for example.  Three messages are involved in this procedure.

 

1) Delegated Bandwidth Query Request
2) Delegated Bandwidth Query Response: used as a successful response, Result field always Success (0x3)
3) Multicast Status Message: used as a failed response

 

I am wondering why we can not allow the Result field to be set other values than Success (0x3), e.g.  Failure (0x4).
In fact, I think we can use Delegated Bandwidth Query Response for both the successful and failed cases if we don't force to Result field to be always Success (0x3).  Then only two messages are involved in the Delegated Bandwidth Query procedure:

 

1) Delegated Bandwidth Query Request
2) Delegated Bandwidth Query Response: Result field Success (0x3) for successful case, Result field Failure (0x4) for failed case

 

As far as I know, TLVs could be optional. The message sender can decide which TLVs should be included in the message in different cases. If you look at Diameter protocol, it is just like this. So I think it would be more reasonable using one message for the response no matter it is a successful or failed response. That is also why we need a Result field in the response message.

 

 

Best regards,

Fortune