Subject: [MEXT] Revocation Status Values

From: "Vijay Devarapalli" <[email-masked]>
Date: Tue, 24 Mar 2009 21:10:36 -0400

Hello,

draft-ietf-mext-binding-revocation-04.txt defines the following status
value for the Binding Revocation Ack message.

       0  success
       1  partial success
       128  Binding Does NOT Exist
       129  IPv4 HoA Binding Does NOT Exist
       130  IPv4 Home Address Option Required
       131  Global Revocation NOT Authorized
       132  CAN NOT Identify Binding
       133  Revocation Failed - MN is Attached

Isnt '128' the same as '132'?

Vijay

---

From: "Ahmad Muhanna" <[email-masked]>
Date: Wed, 25 Mar 2009 01:27:11 -0500

Hi Vijay,

They sound similar but the scenarios are different. Probably we need a
better naming for the second one.

128 "Binding Does NOT Exist" When the information included in the BRI is
enough to identify the mobile node binding BUT it happened that the
binding does not exist or maybe has been released a little earlier
possibly a race condition.

132 "CAN NOT Identify Binding" The case when the information or the
mobility options included in the BRI is NOT enough to identify a mobile
node binding, then the MAG would send this status to indicate that more
information is needed.

Here is the related text:

  o   If the Global (G) bit is set and the Revocation Trigger field is
      set to "Revoking Mobility Node Local Policy", and no mobility
      options are included in the Binding Revocation Indication message
      or the MAG is not able to identify the impacted mobile nodes
      bindings based on the included mobility options, the MAG MUST
      treat this as an error scenario.  In this case, the MAG SHOULD
      send a Binding Revocation Acknowledgement message with status "CAN
      NOT Identify Binding".

Actually this text should say:

  o   If the Global (G) bit is set and the Revocation Trigger field is
      set to "Revoking Mobility Node Local Policy" and no mobility
      options are included in the Binding Revocation Indication message,
      the MAG will not able to identify the impacted mobile nodes
      bindings. In this case, the MAG MUST treat this as an error
scenario
      and reject the BRI by sending a BRA message with status value "CAN
NOT Identify Binding"

On the other hand, at any point the MAG is NOT able to locate the MN
binding while the included options are enough to identify the binding,
the MAG will send status "Binding does NOT exist"

Is this change acceptable?

Regards,
Ahmad

> -----Original Message-----
> From: Vijay Devarapalli [mailto:[email-masked]] 
> Sent: Tuesday, March 24, 2009 6:11 PM
> To: Muhanna, Ahmad (RICH1:2H10)
> Cc: mext
> Subject: Revocation Status Values
> 
> Hello,
> 
> draft-ietf-mext-binding-revocation-04.txt defines the 
> following status value for the Binding Revocation Ack message.
> 
>        0  success
>        1  partial success

---

From: Vijay Devarapalli <[email-masked]>
Date: Wed, 25 Mar 2009 11:14:34 -0700

> node binding, then the MAG would send this status to indicate that more

I don't see the difference. When the LMA receives these two status 
values, the conclusion is the same. There is no corresponding binding 
that the MAG could identify based on the information it sent in the BRI 
message.

> the MAG will send status "Binding does NOT exist"

I don't see why you need to differentiate between the two. It is very 
hard to reflect these subtle differences in an implementation :)

> Is this change acceptable?

What do we lose by having the following text?

   o   If the Global (G) bit is set and the Revocation Trigger field is
       set to "Revoking Mobility Node Local Policy" and no mobility
       options are included in the Binding Revocation Indication message,
       the MAG will not able to identify the impacted mobile nodes
       bindings. In this case, the MAG MUST treat this as an error
       scenario and reject the BRI by sending a BRA message with status
       value "Binding Does not Exist".

Vijay

---

From: "Ahmad Muhanna" <[email-masked]>
Date: Fri, 27 Mar 2009 00:58:51 -0500

Hi Vijay,

> Subject: Re: Revocation Status Values
> 
> Ahmad Muhanna wrote:
> > Hi Vijay,
> > 
> > 128 "Binding Does NOT Exist" When the information included 
> in the BRI 
> > is enough to identify the mobile node binding BUT it 
> happened that the 
> > mobility options included in the BRI is NOT enough to identify a 
> > mobile node binding, then the MAG would send this status to 
> indicate 
> > that more information is needed.
> 
> I don't see the difference. When the LMA receives these two 
> status values, the conclusion is the same. There is no 
> corresponding binding that the MAG could identify based on 
> the information it sent in the BRI message.

[Ahmad]
Hmmm...
I am not sure that is a valid conclusion.
Probably I did not explain the scenario well. In the case of the (G) bit
set and the R. Trigger set to "Revoking Mobility Node Local Policy", the
MAG or the LMA MUST include at least one option that is common among the
group of mobile nodes that their bindings need to be deleted. If the MAG
or the LMA includes nothing, it means that the MAG or the LMA is
violating the specification. Something like poorly formed.

The other scenario is based on most probably a race condition.
Everything in the BRI is good and dandy BUT the session is gone.

One status inform the sending mobility node that it is doing something
wrong and the other one just stating the fact that the session is gone
but before BRI got processed. I am okay of naming "CAN NOT Identify
Binding" for example: "Mobile Nodes Binding Identity REQUIRED" or
something like that.

> >       and reject the BRI by sending a BRA message with status value 
> > "CAN NOT Identify Binding"
> > 
> I don't see why you need to differentiate between the two. It 
> is very hard to reflect these subtle differences in an 
> implementation :)
[Ahmad]
Please my comment above.

>        value "Binding Does not Exist".
[Ahmad]
Please see my response above. I believe these two different scenarios
and need to be handled differently. I do not see the complexity here. As
I mentioned above, the naming may need to change but they are different
scenarios.

> >> draft-ietf-mext-binding-revocation-04.txt defines the following 
> >> status value for the Binding Revocation Ack message.
> >>
> >>        0  success
> >>        1  partial success

---

From: Vijay Devarapalli <[email-masked]>
Date: Mon, 30 Mar 2009 13:26:41 -0700

> Binding" for example: "Mobile Nodes Binding Identity REQUIRED" or

I am not entirely convinced, but its fine. Lets move on.

Vijay