NETEXT Working Group CJ. Bernardos Internet-Draft A. de la Oliva Intended status: Informational UC3M Expires: September 2, 2010 JC. Zuniga InterDigital Communications, LLC T. Melia Alcatel-Lucent Bell Labs March 1, 2010 Applicability Statement on Link Layer implementation/Logical Interface over Multiple Physical Interfaces draft-bernardos-netext-ll-statement-00 Abstract The NETLMM WG standardized Proxy Mobile IPv6 (PMIPv6). PMIPv6 enables mobile devices to connect to a PMIPv6 domain and roam across gateways without changing the IP address. PMIPv6 also provides limited multi-homing support to multi-mode mobile devices. Proxy mobility is based on the assumption that changes in host IP stacks are undesirable. However, link layer implementations can hide the actually used physical interfaces from the IP stack. These techniques can be used to achieve inter-access handovers or flow mobility, i.e., the movement of selected flows from one access technology to another. It is assumed that an IP layer interface can simultaneously and/or sequentially attach to multiple MAGs (possibly over multiple media). This document provides an informational applicability statement that analyzes the issues involved with this approach and characterizes the contexts in which such use is or is not appropriate. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." Bernardos, et al. 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Bernardos, et al. Expires September 2, 2010 [Page 2] Internet-Draft Link Layer Applicability Statement March 2010 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Hiding access technology changes . . . . . . . . . . . . . . . 4 3. Applicability Statement . . . . . . . . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.1. Normative References . . . . . . . . . . . . . . . . . . . 6 7.2. Informative References . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 Bernardos, et al. Expires September 2, 2010 [Page 3] Internet-Draft Link Layer Applicability Statement March 2010 1. Introduction Proxy Mobile IPv6 (PMIPv6), specified in [RFC5213], provides network based mobility management to hosts connecting to a PMIPv6 domain. PMIPv6 introduces two new functional entities, the Local Mobility Anchor (LMA) and the Mobile Access Gateway (MAG). The MAG is the first layer three hop detecting Mobile Node's (MN) attachment and providing IP connectivity. The LMA is the entity assigning one or more Home Network Prefixes (HNPs) to the MN and is the topological anchor for all traffic from/to the MN. Proxy mobility is based on the assumption that changes in host IP stacks are undesirable. However, link layer implementations can hide the actually used physical interfaces from the IP stack. These techniques can be used to achieve inter-access handovers or flow mobility, i.e., the movement of selected flows from one access technology to another. It is assumed that an IP layer interface can simultaneously and/or sequentially attach to multiple MAGs (possibly over multiple media). This document provides an informational applicability statement that analyzes the issues involved with this approach and characterizes the contexts in which such use is or is not appropriate. 2. Hiding access technology changes TO BE COMPLETED There are several techniques/mechanisms that allow to hide access technology changes from host IP layer. This section classifies these existing techniques into a set of generic approaches, according to their most representative characteristics. This would allow to refer to these generic mechanisms later in the document, when analyzing their applicability to inter-tech and flow mobility purposes in PMIPv6. So far, we have identified the following generic mechanisms to hide access technology changes from host IP layer: o Link layer support: certain link layer technologies are able to hide physical media changes from the upper layers. For example, IEEE 802.11 is able to seamlessly change between IEEE 802.11abg physical modulations without the IP stack even being aware, as the IEEE 802.11 MAC layer takes care of it, making the mecia change transparent to the upper layers. Another example ies IEEE 802.3, that support changing the rate from 10Mbps to 100Mbps and to 1000Mbps. (e.g. EPS solution, IEEE 802.11). While the previous two changes might seem simple, as they "just" involve physical Bernardos, et al. Expires September 2, 2010 [Page 4] Internet-Draft Link Layer Applicability Statement March 2010 media changes (mainly modulation schemes) between the same two communication nodes (e.g., STA and AP in IEEE 802.11), there are other examples, with a more complicated architecture. As an example of those, we can refer to 3GPP Rel-8. A UE can move (inter-RAT handover) between GERAN/UTRAN/E-UTRAN, being this movement transparent to the IP layer at the UE, and also to the LMA logical component at the PGW. The link layer stack at the UE (i.e. PDCP and RLC layers), and the GTP between the RAN and the SGW (which plays the role of inter-3GPP AN mobility anchor) hide this kind of mobility, which is not visible to the IP layer of the UE. o Logical interface: by this name we can group the solutions than logically group/bond several physical interfaces so they appear to the upper layers (i.e. IP) as one single interface (where application sockets bind). Depending on the OS support, it might be possible to use more than one physical interface at a time -- so the node is simultaneously attached to different media -- or just to provide a fail-over mode. Controlling the way the different media is used (simultaneous, sequential attachment, etc) is not trivial and requires additional intelligence and/or configuration at the logical interface device driver. An example of this type of solution is the virtual interface or the bonding driver. o Layer 2.5 solution: another potential solution is to add a layer 2.5 on top of the multiple L2 media, that takes care of making inter-media support transparent. 3. Applicability Statement TBD. 4. IANA Considerations This document makes no request of IANA. 5. Security Considerations TBD 6. Acknowledgments The research of Carlos J. Bernardos and Antonio de la Oliva leading Bernardos, et al. Expires September 2, 2010 [Page 5] Internet-Draft Link Layer Applicability Statement March 2010 to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n. 214994 (CARMEN project). The work of Carlos J. Bernardos has also received funding from the Ministry of Science and Innovation of Spain, under the QUARTET project (TIN2009-13992-C02-01 7. References 7.1. Normative References [RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008. 7.2. Informative References [RFC5164] Melia, T., "Mobility Services Transport: Problem Statement", RFC 5164, March 2008. Authors' Addresses Carlos J. Bernardos Universidad Carlos III de Madrid Av. Universidad, 30 Leganes, Madrid 28911 Spain Phone: +34 91624 6236 Email: cjbc@it.uc3m.es URI: http://www.it.uc3m.es/cjbc/ Antonio de la Oliva Universidad Carlos III de Madrid Av. Universidad, 30 Leganes, Madrid 28911 Spain Phone: +34 91624 8803 Email: aoliva@it.uc3m.es URI: http://www.it.uc3m.es/aoliva/ Bernardos, et al. Expires September 2, 2010 [Page 6] Internet-Draft Link Layer Applicability Statement March 2010 Juan Carlos Zuniga InterDigital Communications, LLC Email: JuanCarlos.Zuniga@InterDigital.com Telemaco Melia Alcatel-Lucent Bell Labs Email: Telemaco.Melia@alcatel-lucent.com Bernardos, et al. Expires September 2, 2010 [Page 7]