Subject: [MOBILE-IP] v4 fast handoff lack of interest?

From: Roberts Philip-qa3445 <[email-masked]>
Date: Tue, 7 Nov 2000 16:04:53 -0600

Hi folks,

        I'm perceiving the working group has a lack of interest in the v4
fast handoff proposals.  The v4 team did its work and produced two drafts:
draft-calhoun-mobileip-proactive-fa-02.txt
draft-elmalki-mobileip-fast-handoffs-03.txt

        There was a list of differences posted and a pointer to the design
team archive.  There were a couple of messages by people who were in the
design team as a follow-up but little other group comment.

        Raj and I are trying to discern whether the working group is a)
uninterested in making a decision about the proposals (either one is fine)
or b) uninterested in having a v4 fast handoff work item because it's not
perceived as something that's going to be used.  It's hard for us to draw
any conclusions on this without some comments.  Care to give us a sense
about it?

Thanks,
Phil

---

From: "M. Scott Corson" <[email-masked]>
Date: Wed, 8 Nov 2000 11:47:55 -0500

>any conclusions on this without some comments.  Care to give us a sense

Phil,

Just on time we have some comments.....and you thought that no one cared :-)

We feel that the FA assisted approach has a number of advantages over the
fast handoff approach. Most of the arguments, however, have been made
already in this list (see McCann's "[MOBILE-IP] Differences between the two
MIPv4 handoff approaches" for an example). The most important arguments
against Fast Handoff from our point of view is:
1. Increased signaling on the old link; which might be degrading.
2. Ability of the FA assisted approach to support vanilla RFC2002 MIP clients.

We do, however, feel that the FA assisted proposal can be improved.

Please consider the following modifications:
Lets use the basic idea of Source and Destination Trigger but also support
the following:
1. A temporary tunnel between old FA and new FA (whether GFA/AFA is used or
not)
2. The creation of this temporary tunnel to be based on BR/BU/BUAck
messages (see below)
3. Regional/Hierarchical mobile IP signaling to be optionally used in
parallel to the 1,2

In more particular:

                                                 +-----+
                                                 | GFA |
                                                 +-----+
                                                  ^  |
                                 2b. Regional Reg |  | 3b. Regional Reply
                                                  |  |
                                                  |  v
                      +-----+ 1. Binding Update  +-----+
                      |     | -----------------> |     |
                      | oFA | 2. Binding Ack     | nFA |
                      |     | <----------------- |     |
                      +-----+                    +-----+

                      +-----+    Movement        +-----+
                      | MN  | - - - - - - - - -> | MN  |
                      +-----+                    +-----+
       Figure 4 - "source trigger" hand-off optionally using either AFA or GFA

- 1 & 2 are mandatory messages that set a temporary (optionally
bi-directional) tunnel between oFA and nFA
- 2b & 3b are optional messages used if the BU includes a GFA or AFA address

                                                 +-----+
                                                 | GFA |
                                                 +-----+
                                                  ^  |
                                 3b. Regional Reg |  | 4b. Regional Reply
                                                  |  |
                              1. Binding Request  |  v
                      +-----+ <----------------  +-----+
                      |     | 2. Binding Update  |     |
                      | oFA | -----------------> | nFA |
                      |     | 3.  Binding Ack    |     |
                      +-----+ <----------------- +-----+

                      +-----+    Movement        +-----+
                      | MN  | - - - - - - - - -> | MN  |
                      +-----+                    +-----+
       Figure 5 - "target trigger" hand-off using either AFA or GFA

- 3b & 4b are optional messages used if the BU includes a GFA or AFA address
- 1 & 2 & 3 are mandatory messages that set a temporary tunnel between oFA
and nFA

The above modified version of the FA assisted has the following advantages:
1. Fast Handoff is isolated from Regional Registration or other
hierarchical signaling.
2. The proactive establishment of the temporary tunnel between oFA and nFA
provides Fast Handoff and helps to ensure zero packet loss during handoff
3. Retains the main advantages of the original FA assisted proposal:
   - support for vanilla RFC2002 MIP clients,
   - no additional signaling over the radio link.
   - optional support for Regional Registration (or other hierarchical
solutions)

-Scott C. (and George T.)

---

From: "Hesham Soliman (EPA)" <[email-masked]>
Date: Thu, 9 Nov 2000 07:31:06 +1100

Scott,

        Thanks for the interest. I have a comment on your
        criteria below.

        Hesham

> 1. Increased signaling on the old link; which might be degrading.
        => That's a system specific issue.

> 2. Ability of the FA assisted approach to support vanilla RFC2002 MIP
        => Actually to say that proactive only supports RFC2002 vanilla
        MIP clients is a wrong statement. I think both proposals support
        RFC2002 clients. However, the Fast Handoffs model is closer
        to RFC2002 than the proactive model. Note I'm talking about
        the overall model of shared control between he MN and the network.
        But Both support the RFC2002 MIP clients.

        Regards,
        Hesham