Re: [Mip4] review of draft-devarapalli-mip4-mobike-connectivity-00.txt

Hi Jari,

> I finally found time to read this draft. Overall, I like it
> a lot. Some of its good properties include simplicity,
> minimal changes to both existing VPN plumbing and
> MIPv4 systems, and the separation between the two.
> I support taking this work forward.

The problem I see w.r.t. to using IKEv2/MOBIKE is that it does
not, alone, match the current problem statement.  The assumption
made in draft-ietf-mip4-vpn-problem-statement-03.txt is that
existing deployed VPN infrastructure should be used (see e.g.
Section 5.1).

As far as I can see, this makes IKEv1 support mandatory, which
is reflected in the current VPN solution draft (essentially the
same mechanism, but uses an outer MIPv4 layer to compensate for
lack of IPsec mobility support).

If we drop the "deployed VPN" requirement, we're defining a new
solution for the problem.  Such a solution does not ease the
perceived MIPv4 deployment issue of existing VPN infrastructure.
I'm not sure the perception is correct, but it was included in
the problem statement because several vendors thought it was
relevant.

If we decide that there is no deployment issue w.r.t. MIPv4 and
already deployed VPNs, we should IMO take a larger view of
improving MIPv4/VPN coexistence.  Minimizing overlap between
the two mechanisms would give a much better solution.  For
instance, there is room for improvement in MIPv4 packet overhead,
MIPv4/VPN compression interactions, and integrated MIPv4/VPN
packet authentication.

As discussed in earlier e-mails, I believe that:

  1. A solution document should address current VPN deployment.

  2. There are multiple VPN technologies currentl in use.  For
     instance, let's not forget L2TP/IPsec which probably accounts
     for a sizable chunk of deployments.

  3. Because no new protocols are needed specifically for MIPv4/VPN
     coexistence, the most appropriate way of dealing with the
     solution space would be an applicability statement of existing
     protocols for the enterprise scenario.

Best,

-Sami

-- 
Mip4 mailing list: Mip4@ietf.org
    Web interface: https://www1.ietf.org/mailman/listinfo/mip4
     Charter page: http://www.ietf.org/html.charters/mip4-charter.html
Supplemental site: http://www.mip4.org/