Subject: RE: [mobile-ip] Reverse tunneling issues

From: George Tsirtsis <[email-masked]>
Date: Tue, 2 Apr 2002 04:28:28 -0500

Jari,

Here is the deal...

draft-oneill-mip-revtun-ho-00.txt in section 6. "IPv6 Considerations"
currently suggest:
"The IPv6 HA should support the automatic invocation of a fan-in binding if
reverse tunneling is requested."

"Fan-in bindings" are explained earlier in the document
This essentially says that when reverse tunneling is used the HA has to
maintain at least 2 bindings for the MN, at least for a short time during
handoff. 

So for example, 
- Assume a MN that uses reverse tunneling
- After the MN hands off to a new CoA it sends the appropriate BU to the HA
- The HA registers the new binding to the newCoA and immediately uses it for
all downlink traffic.
- The HA also keeps the oldCoA binding for a while but only uses it so that
it can accept in-flight packets from that oldCoA
- The old binding is removed if/when the MN moves to yet another (third) CoA
or after a default timeout.

The above works for both MIPv4 and MIPv6 and does not require any signaling
changes, but only behavior changes at the HA i.e.: currently a new Binding
REPLACES the old Binding. The text needs to be revised to say that the new
Binding REPLACES the old Binding for downlink traffic but it is ADDED to the
old Binding for reverse tunneled traffic.

Also note that while the above helps, it does not solve the problem
completely for reasons explained in the draft. To solve all problems with
reverse tunneling we need signaling changes/extensions which I guess could
be described in a new draft.

Does this make sense?

Regards
George

-----Original Message-----
From: Jari Arkko [mailto:[email-masked]]
Sent: Saturday, March 30, 2002 2:09 PM
To: [email-masked]
Cc: [email-masked]'; [email-masked]'
Subject: Re: [mobile-ip] Reverse tunneling issues

George Tsirtsis wrote:

> GT> No problem...have a look at the draft and do not let the too many
> options of how to solve the problem confuse you ...this is not
complex...it
> is just that it has to be dealt with.

Assuming something has to be done, is this something that has to go to
the base RFC, or something that can be done in an extension separately?

Jari

---

From: gabriel montenegro <[email-masked]>
Date: Tue, 02 Apr 2002 11:33:07 +0200

George,

Your draft talks about IPR on your proposal. Could you clarify how much (if not all)
is covered, etc?

-gabriel

---

From: "James Kempf" <[email-masked]>
Date: Tue, 2 Apr 2002 08:52:32 -0800

George,

While I support this, I'd like to ask you the same question that was
asked about BETH: what causes the old tunnel state to get cleaned up?
People seemed to feel that cleaning up tunnel state in ARs was important
for BETH, and I believe the same argument can be made for the HA.

            jak

---

From: "Kalyan" <[email-masked]>
Date: Tue, 2 Apr 2002 15:15:59 +0530

George,
            Are there any latest enhancements proposed for Mobile IPv4.what
all rfcs should be considered for those advanced features.Please let me know
at the earliest.

regards,
Kalyan.