Subject: RE: [mobile-ip] Mobile Prefix Advertisements ... additional thoug ht

From: "Powell, Ken" <[email-masked]>
Date: Mon, 7 May 2001 16:54:05 -0400

I've been wondering about the coupling between mobile
prefix solicitation/advertisement and binding request/
update/ack.

Specifically:
 - Section 9.8.2 describes how a binding update could
   trigger a mobile prefix advertisement
 - Section 9.8.3 describes how a binding request/update is
   used to acknowledge the mobile prefix advertisement

This leads me to consider the following exchange:

   mobile node <--> home agent
   ===========================
   --> binding update w/ ack bit set
       (destination option processing on home agent handles
        processes binding update and sends binding ack,
        then signals ICMP mobile prefix handler to check
        for pending advertisements)
   <-- binding ack
   <-- mobile prefix advertisement w/ binding request
   --> binding update w/ ack bit set
   <-- binding ack

   It seems we could simplify the exchange rules by
   adding an ICMP mobile prefix ack message that could be
   used to replace the final binding request/update/ack
   exchange.

   --> binding update w/ ack bit set
   <-- binding ack
   <-- mobile prefix advertisement
   --> mobile prefix ack

Ken