Subject: [netext] New I-D draft-savolainen-netext-intertech-handover-00

From: <[email-masked]>
Date: Thu, 2 Jul 2009 22:36:41 +0200

Hi Netext,

Here is a draft-savolainen-netext-intertech-handover, which replaces the draft-premec-netlmm-intertech-handover-01.txt, and is related to NETEXT2 discussion on inter-technology handover support extension for PMIP6.

http://www.ietf.org/internet-drafts/draft-savolainen-netext-intertech-handover-00.txt

Abstract:
--
   Proxy Mobile IPv6 [RFC5213] is a network based mobility management
   protocol which provides IP mobility service to a host in a way which
   is transparent to the host itself.  This document analyses the
   scenarios in which a multi-interfaced Mobile Node roams in a Proxy
   Mobile IPv6 domain which consists of access networks that are of
   different types.  In order to support session continuity as the
   Mobile Node moves between access networks within the PMIP6 domain,
   the Mobile Node either needs to use host based Mobile IP or be
   enhanced with various capabilities described in this document.
--

You may be particularly interested on chapter 11, where we conclude:
--
11.  Conclusions and recommendations

   It is clear that for IP session continuity during PMIP6 inter-
   technology handovers changes on many if not all operating systems are
   necessary.  While there are several technical ways to accomplish
   that, as described earlier, all those require support from both hosts
   and access network elements.

   Enhancing the MN with functionality to achieve inter-technology
   handovers is almost the same as installing host based mobility
   support.  Since host based mobility is already specified and is
   capable of accomplishing inter-technology handovers and flow
   mobility, there is no reason to reinvent the same in the case of
   PMIP6.  Therefore we recommend to:

   1.  Use host based mobility solutions, such as DSMIP6 [RFC5555], for
       inter-technology handovers.  DSMIP6 has the benefit of not
       requiring special support from access networks (such as WLAN
       hotspots), it allows overlapping IPv4 care-of addresses, and has
       been standardized already.

   2.  On access technologies where PMIP6 based handovers are absolutely
       required, it is best to standardize access technology specific
       solutions that provide intra-technology looking handovers for
       hosts.

   3.  In the case NetExt working group chooses to standardize inter-
       technology handovers for PMIP6, we propose doing that with
       changes to DHCPv4 and to DHCPv6 and/or Router Solicitation/Router
       Advertisements as described in this document.
--

Best regards,

	Teemu

---

From: Behcet Sarikaya <[email-masked]>
Date: Thu, 2 Jul 2009 14:10:49 -0700 (PDT)

Hi Teemu,

snipped the beginning.

>       been standardized already.

Yes it is true that PMIPv6 requires special support on Wi-Fi links.

>       solutions that provide intra-technology looking handovers for

This is very difficult if not impossible in WiMAX because PHY/MAC is IEEE based which is another SDO.

I think that WiMAX is very important for PMIPv6.

>       Advertisements as described in this document.

Why? Why not MN-AR interface?

Regards,

Behcet

---

From: <[email-masked]>
Date: Thu, 2 Jul 2009 23:24:59 +0200

Hi,

(FYI: I'm on vacation so not very able to answer emails - I look forward on discussions around IETF).

>-----Original Message-----
>From: ext Behcet Sarikaya [mailto:[email-masked]] 
>Sent: 03 July, 2009 00:11
>To: Savolainen Teemu (Nokia-D-MSW/Tampere); [email-masked]
>Subject: Re: [netext] New I-D 
>draft-savolainen-netext-intertech-handover-00
>

We wrote to draft the following, does it help to answer your question?
--
   o Same interface identifier across access networks

   This approach is suggested in the [I-D.ietf-netlmm-mn-ar-if].  The
   idea is that the MN uses the same interface identifier in both access
   networks if it wants to move its IP session across interfaces.  A MAG
   in a new access network is assumed to acquire the MN's interface
   identifier during the link establishment phase through link specific
   mechanisms.  A MAG is also assumed to obtain an interface identifier
   that the MN was using at a previous MAG and the access technology
   type through context transfer between MAGs or some other unspecified
   mechanisms.  If access technology type is different and the interface
   identifier is the same in both access networks than the new MAG
   should take that as an indication of the MN's capability and
   intention to move its IP sessions across interfaces.  In this case
   the MAG would set the handoff indicator in the PBU message to the
   value "2: Handoff between two different interfaces of the mobile
   node".  This solution is partly dependent on a link-layer as the MAG
   learns the MN's interface identifier during the link layer
   establishment.  Note that there are link layers which do not allow
   for MAC address negotiation and where the MAC address assigned to the
   device is authenticated by the certificate and thus can not be
   changed.  One example of such link layer is IEEE 802.16 defined in
   [IEEE802.16] and [IEEE802.16e].  The interface identifier approach is
   further complicated if the host is simultaneously utilizing multiple
   IPv6 addresses configured from the same prefix.
--

Best regards,

	Teemu