Subject: [Mip6] New draft on make-before-break handoffs in Mobile IPv6

From: Henrik Petander <[email-masked]>
Date: Sun, 23 Oct 2005 19:36:46 +1000

Hi all,

We have written an internet draft on make-before-break handoffs in
Mobile IPv6. The draft proposes improvements to Mobile IPv6 binding
management for make-before-break handoffs to avoid packet loss during handoffs.
The draft is available at the ietf website:

http://www.ietf.org/internet-drafts/draft-petander-mip6-mbb-00.txt

Abstract:

"Mobile IPv6 binding management has been designed for
break-before-make handoffs, which can be performed by hosts equipped
with a single interface. However, a mobile node may be equipped with
multiple interfaces, allowing it to perform make-before-break handoffs
by connecting simultaneously to two overlapping access networks during
the handoff. In theory these handoffs can be lossless, provided that
there is sufficient overlap between the two networks. However, unless
Mobile IPv6 bindings are managed carefully mobile node and
correspondent node will have inconsistent binding state during the
handoff, which will lead to packet loss. In this draft we propose
changes to binding management for lossless make-before-break handoffs.
The proposed changes do not affect the interoperability with Mobile
IPv6 nodes not implementing these changes."

For background information: We measured the performance of Mobile IPv6
in make-before-break handoffs with two interfaces and noticed bad
performance when there was network latency between MN and HA.  Packets
sent between BU and BA were dropped either by HA or MN, depending on
whether handoff in MN was performed when sending BU or receiving BA.
We implemented the MN part of the draft and verified that the proposed
change fixed the problem and allowed lossless handoffs for MIPv6, so
the modifications to MIPv6  work also in practice.

Regards,
Henrik Petander

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From: Christian Vogt <[email-masked]>
Date: Mon, 24 Oct 2005 08:09:51 +0200

Hi Henrik,

interested folks might also want to take a look at the discussion we had
on the Monami6 mailing list, starting here:

http://www1.ietf.org/mail-archive/web/monami6/current/msg00265.html

E.g., that thread attended to make-before-break handoffs with only a
single interface rather than two.

- Christian

-- 
Christian Vogt, Institute of Telematics, University of Karlsruhe
www.tm.uka.de/~chvogt/pubkey/