Subject: [MEXT] FW: I-D Action:draft-muhanna-mext-binding-revocation-01.txt

From: "Benjamin Lim" <[email-masked]>
Date: Sat, 17 May 2008 15:06:27 +0800

Hi Ahmad,

I snipped sections from the draft to reflect some comments (mostly
editorial).

Regards,
Benjamin Lim

----------

3.1.  Binding Revocation Protocol

...
On the other hand, the mobility access gateway usually sends a de-
registration message by sending a Proxy BU with a lifetime of zero to
indicate to the local mobility anchor of the termination of the
PMIPv6 mobile node binding registration.  In this case, the mobility
access gateway include the MN home network prefix option and the
MN-ID option as per [2] in order for the local mobility anchor to
identify the mobile node PMIPv6 binding.  However, in the case when
the mobility access gateway communicates a bulk termination of PMIPv6
sessions, the mobility access gateway sends a BRI message with the G
bit set and includes the mobility access gateway identity in the
MN-ID option.  When the local mobility anchor receives such BRI
message, it ensures that the mobility access gateway is authorized to
send such bulk termination message and then process the BRI message
accordingly.  If the local mobility anchor processes the BRI message
successfully and the (A) bit is set in the BRI, the local mobility
anchor responds to the mobile access gateway by sending a BRA
message.  Aditionally, the initiator of the binding revocation
               ^^^^^^^^^
[Ben] Additionally

procedure include an indication in the Revocation Trigger field to
indicate to the receiving node the cause for the revocation
procedure.

...

3.3.1.  Termination of Multiple Care-of Addresses Bindings

In the case of multiple care-of addresses, the home agent maintains
different binding for each pair of care-of address and home address.
These bindings are also indexed and identified during the mobile node
registration using a new Binding ID mobility option [5].  In this
case, the home agent may revoke any binding, more than one binding,
or all of the bindings for the same mobile node home address.

[Ben] Suggest reword above sentence to "In this case, the home agent may
revoke either one or multiple of the mobile node's binding associated to the
mobile node's home address."

...

Figure 2: Home Agent Revokes MN's Specific Registered Care-of Addresses
Bindings

[Ben] What is 'Cause' specified in the BRA from MN to HA?

...

3.4.1.  Local Mobility Anchor Revokes A PMIPv6 Binding

The local mobility anchor may send a BRI message to the mobile access
gateway, hosting a specific proxy mobile IPv6 session, with the
appropriate value in the revocation trigger field to indicate that
the mobile node binding has been terminated and the mobile access
gateway can clean up the applicable resources.  When the mobile
access gateway receives a BRI message, the MAG identify the respected
 
^^^^^^^
[Ben] respective

binding and if the A bit was set in the received BRI message, the MAG
sends a BRA message to the LMA.  In this case, the MAG could send a
Router Advertisement message to the MN with the home network prefix
lifetime is set to zero.

As an example, Figure 3, illustrates the message sequence for
revoking a mobile node binding at the source MAG during the MN inter-
MAG handoff.  During the inter-MAG handoff, the mobile node moves
from the source MAG to the target MAG.  The target MAG sends a PBU
with the new care-of-address to the LMA to update the mobile node
point of attachement.  Since the MN binding at the LMA points to the
            ^^^^^^^^^^
[Ben] attachment
 
source MAG and upon receiving the PBU from the target MAG, LMA
updates the MN BCE and send a PBA to the target MAG.  LMA can send a
BRI message with the appropriate revocation trigger value, e.g.
inter-MAG handoff indication, to the source MAG in order to clean up
the applicable resources reserved for the specified MN.  The MAG
acknowledges the BRI message by sending a BRA message to indicate the
success or failure of the termination of the mobile node binding.

The process identified above can also be used by the LMA in scenarios
other than the inter-MAG handoff with the propoer revocation trigger
                                                                ^^^^^^^
[Ben] proper

value to indicate to the peer MAG that a specific proxy mobile IPv6
binding or bindings have been revoked.

Figure 3: LMA Revokes a MN Registration During Inter-MAG Handoff

[Ben] What is 'Cause' specified in the BRA from sMAG to LMA?

...

3.4.3.  Mobile Access Gateway Revoke Bulk PMIPv6 Bindings

The mobile access gateway send a de-registration PBU with lifetime of
zero as described in [2] to indicated to the LMA the termination of a
mobile node registration binding.  However, the mobile access gateway
sends a BRI message with the G bit is set to indicate that all
mobility sessions which are registered at the LMA and attached to the
MAG are being revoked as in Section 9.2.1.  When the LMA receives a
BRI message with the G bit is set from a specified MAG, the LMA
checks if the MAG is authorized to use global revocations and
responds with the approporiate status code by sending a BRA message
                           ^^^^^^^^^^
[Ben] appropriate

as in Section 8.2.2.

...

5.1.  Binding Revocation Indication Message

...
Binding ID mobility option [5].  This option is mandatory if the
sending mobility entity request to terminate one binding of a
multi care-of addresses bindings for the same mobile node.  

[Ben] Suggest reword above sentence to "This option is mandatory if the
sending mobility entity request to terminate a multiple care-of address
registered binding of a mobile node."

The sending Mobility entity may include more than one of these
mobility options.

...

6.1.  Sending Binding Revocation Messages

When a mobility entity initiate the binding revocation process by
sending a Binding Revocation Indication, the initiator MUST construct
the BRI message as described in Section 5.1.  In the BRI message, the
initiator MUST set the Sequence Number field to the next sequence
number available for Binding Revocation.  Since sending Binding
Revocation Indication messages is not done on a regular basis, a 16
bit sequence number field is large enough to allow the initiator to
match the Binding Revocation Acknowledgement to the outstanding
Binding Revocation Indication with (A) bit set using the seqeuence
 
^^^^^^^^
[Ben] sequence

number field only.

...

6.3.  Retransmission of Binding Revocation Indication

If the sending mobility entity does not receive a Binding Revocation
Acknowledgement in response to the outstanding Binding Revocation
Indication before the MINDelayBRIs timer expires, the mobility
entity, e.g.  LMA, may retransmit the same BRI message upto the
 
^^^^
[Ben] up to

BRIMaxRetriesNumber as defined in Section 11.  If the revoking
mobility entity does not receive a BRA message after the maximum
number of retrasmits have been sent, the revoking mobility entity can
                ^^^^^^^^^^^^^^^^^^^
[Ben] retransmissions (remove "have been sent" as transmit implies sending)

clean the mobile node binding cache and all resources associated with
this binding.  The revoking mobility entity may log the event.

...

7.2.  Receiving Binding Revocation Acknowledgement

...

If the Status field indicates any value other than success, the
home agent SHOULD examine any mobility options included in the
Binding Revocation Acknowledgement.  The home agent MAY log the
approriate event to reflect the status of the received BRA.
^^^^^^^^
[Ben] appropriate

...

8.1.1.  Sending Binding Revocation Indication

...

When the local mobility anchor needs to revoke all mobile nodes proxy
BCE that belong to a specific realm, e.g. @companyabc.com, and are
registered with the local mobility anchor and hosted at the mobile
access gateway, 

[Ben] Suggest reword the above to "When the local mobility anchor needs to
revoke all currently registered mobile nodes proxy BCE that belong to a
specific realm (e.g. @companyabc.com) at a particular mobile access
gateway,"

the local mobility anchor MUST set the Global (G) bit
and the value of the Revocation Trigger field to Local Policy.  In
this case, the local mobility anchor MUST include a mobility option
to identify the impacted bindings, e.g.  MN-ID option with a wildcard
NAI, e.g. [email-masked], to identify all the mobile nodes BCEs
that need to be removed.

[Ben] Is there such a thing as a wildcard NAI? Why can't the LMA just
include every single affect MN-ID as an option in the BRI?

...

8.2.1.  Receiving Binding Revocation Indication

...

The Revocation Trigger field value in the received Binding Revocation
Indication could be used by the local mobility anchor to log an event
or update some local parameters which tracks the satate of the peer
 
^^^^
[Ben] state

mobile access gateway.

...

9.1.2.  Sending Binding Revocation Acknowledgement

...

When the mobile access gateway receive a valid Binding Revocation
                                                  ^^^^^^
[Ben] receives

Indication with the (A) bit is set and after processing the BRI
message, the mobile access gteway sends a packet to the local
                                         ^^^^^^
[Ben] gateway

mobility anchor containing a Binding Revocation Acknowledgement
according to the procedure in Section 6.1 and the following:

...

9.2.1.  Sending Binding Revocation Indication

...

The mobile access gateway send a Binding Revocation Indication when
it needs to use global revocation, i.e. when the G bit is set.  In
this case when an event occurs which requires the mobile access
gateway to inform the local mobility anchor to terminate all mobile
nodes bindings that are registered at the local mobility anchor and
the mobile access gateway, the mobile access gateway send a Binding
Revocation Inidcation message following Section 6.1 and the
                 ^^^^^^^^
[Ben] Indication

follwoing:
^^^^^^^
[Ben] following:

...

9.2.2.  Receiving Binding Revocation Acknowledgement

...

If the Status field indicates (Global Revocation NOT Authorized),
the mobile access gateway is not authorized to participate in a
Per-Peer Global Revocation.  The mobile access gateway SHOULD NOT
retry sending a Binding Revocation Inidication with the Global (G)
                                                     ^^^^^^^^
[Ben] Indication

bit is set to the same local mobility agent.  The mobile access
gateway should raise an alarm or log an event to indicate this
rejection.

...

10.1.  Receiving Binding Revocation Indication

...

If the mobile node has registered multiple care-of addresses with
its home agent, the mobile node MUST verify which binding is being
revoked by examining the content of the BRI message.  If the
mobile node received a Binding Revocation Indication with a single
or more than one BID options and its home adress is in the Home
Address option, 

[Ben] Suggest reword above to "If the mobile node receives a Binding
Revocation Indication containing either a single or multiple BID options
that is associated to its home address specified in the Home Address
option,"

the mobile node MUST consider its bindings
identified in the Binding ID options are being revoked.

_______________________________________________
MEXT mailing list
[email-masked]
https://www.ietf.org/mailman/listinfo/mext