Subject: [nemo] BA(status 140) in explicit mode.

From: "KyeongJin Lee" <[email-masked]>
Date: Thu, 6 Nov 2003 15:22:40 +0900

Hi,
I've a question on the NEMO Basic Support.
 
in sect 6.2
When a HA received BU with R flag set, 
if the H flag is not set, the HA send BA with status set to 140 to MR.

but in sect 5
MR MUST discard BA(status 140) if it is not operate in implicit mode.
 
I wonder why the MR MUST discard the BA(status 140) in explicit mode.
I think MR must process the BA status 140 in all 3 modes.

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From: Alexandru Petrescu <[email-masked]>
Date: Thu, 06 Nov 2003 22:16:56 +0100

KyeongJin Lee wrote:
> Hi, I've a question on the NEMO Basic Support.
> 
> in sect 6.2 When a HA received BU with R flag set, if the H flag is 
> not set, the HA send BA with status set to 140 to MR.
> 
> but in sect 5 MR MUST discard BA(status 140) if it is not operate in 
> implicit mode.

This so happens because the 4 BAck error messages (140...143) are split
in two sets:  140 and 143 for implicit mode and 141 and 142 for explicit
mode.

If the MR sends a BU to HA in implicit mode and receives 140 it will try
the other two explicit modes.

If the MR sends a BU to HA in explicit mode and receives 140 it will
simply discard the error and then that's it, end of the story, its HA
doesn't support network mobility.

>  I think MR must process the BA status 140 in all 3 modes.

Ok, I agree that error processing is difficult to make work. Finding
errors in the error processing procedure itself is a neverending story.
  If we put the forced end as above then loops are avoided.  A loop can
appear when MR cycles between various modes and various HA's and always
getting 140 back.  So we were trying to avoid this loop.

No?

Alex
GBU

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From: Alexandru Petrescu <[email-masked]>
Date: Thu, 06 Nov 2003 22:16:56 +0100

No?

Alex
GBU