Subject: [MOBILE-IP] Questions about the optim-draft

From: Yu Dum <[email-masked]>
Date: Mon, 15 May 2000 22:13:27 +0800

Hello, everyone!

    I have just read the draft-ietf-mobileip-optim-09 and there are
some questions puzzling me. Could you please kindly help me?

  in section 3.1, it says:

 1.The home agent SHOULD then send
   a Binding Update message to the original source node, informing it
   of the mobile node's current mobility binding.  No acknowledgment
   for such a Binding Update message is needed, since additional future
   datagrams from this source node intercepted by the home agent for the
   mobile node will cause transmission of another Binding Update.

   ? why shouldn't there be an acknowledgement, and it seems to conflict
with the description of the Binding Update message which define the 'A'
bit.

 2.Similarly, when any node (e.g., a foreign agent) receives a tunneled
   datagram, if it has a binding cache entry for the destination mobile
   node (and thus has no visitor list entry for this mobile node), the
   node receiving this tunneled datagram may deduce that the tunneling
   node has an out-of-date binding cache entry for this mobile node.

   ? How can the 'any node' deduce whether its or the tunneling node has
an out-of-date binding cache entry for this mobile node?

   Thanks for your answer!

Regards,

Yu

-----*-----*-----*-----*-----*----* * *----*-----*-----*-----*-----*-----
  Miss Yu Du                               Tel: 86-551-3603400-219(lab)
P.O. Box 4 3-167                                86-551-3656437   (Dorm)
Hefei,Anhui
Department of Computer Science&Technology
University of Science and Technology of China
People's Republic of China    230027
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From: Zhao Jian <[email-masked]>
Date: Tue, 16 May 2000 00:17:59 +0800

Hi,

Here is my understanding:

----- Original Message ----- 
From: Yu Dum <[email-masked]>
To: <[email-masked]>
Sent: Monday, May 15, 2000 10:13 PM
Subject: [MOBILE-IP] Questions about the optim-draft

> with the description of the Binding Update message which define the 'A'

The draft does not say "shouldn't",
but says "it is not needed/necessary".
It is better for the home agent to do the task.

> an out-of-date binding cache entry for this mobile node?

when the mentioned mobile is not in FA's visitor list,
this mobile, most likely, has handed-off to another nearby FA.

> Yu

Zhao Jian
Department of Computer Science
HKU of Science & Tech.