NEMO Working Group V. Pangboonyanon INTERNET DRAFT A. Udugama Expires: April 2007 C. Goerg ComNets-ikom, Uni. Bremen F. Pittmann Siemens Networks October 2006 Optimized Routing in Nested NEMO Networks draft-varaporn-nemo-optimized-nested-nemo-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 16, 2007. Copyright Notice Copyright (C) The Internet Society (2006). Abstract In nested mobile networks (NEMO), packets that are routed from/to any nodes inside the nested NEMO have additional overheads (i.e., bi- directional tunnels) and delays. These additional overheads and delays increase respectively to the depth of the current location of the node in nested NEMO since the packets have to go through all the HAs of the MRs along the path to an endpoint. This draft provides a solution to this problem, providing optimizations to the nested NEMO Expires April 2007 1 Internet Draft Optimized Routing in Nested NEMO October 2006 concept thereby making it worthwhile to implement the nested NEMO concept. Table of Contents 1.Introduction.....................................................2 2 Terminology......................................................4 3. Protocol Overview...............................................5 4 Protocol Operations..............................................6 4.1 Care-of-Address (CoA) assignment for VMNs in nested NEMO.......6 4.2 Use of Routing Header..........................................7 4.3 Extended Binding Update........................................7 4.4 Data Transmission..............................................8 4.4.1 For incoming packets.........................................8 4.4.2 For outgoing packets.........................................9 References........................................................10 Authors' Addresses................................................10 1.Introduction According to the current IETF NEMO standardization [1], NEMO introduces the Mobile Router (MR) concept where an MR provides mobility for connected Mobile Network Nodes (MNNs) or other Mobile Routers (MRs), which can lead to the creation of nested structures within the overall moving network. All incoming and outgoing traffic of MNNs, joining a nested moving network by connecting to the nested MRs must go through bi-directional tunnels established between the corresponding MRs and their HAs. Figure 1 shows how the traffic of a MNN connected to a MR (MR3) is routed via all HAs of the MRs of the nested moving network, traversing through different networks. +--+ +------+ |CN| |MR3_HA| Expires April 2007 2 Internet Draft Optimized Routing in Nested NEMO October 2006 +--+ +------+ | | +------+ +-------------------+ +------+ |MR1_HA|--| Internet |--|MR2_HA| +------+ +-------------------+ +------+ | +---+ |MR1| +---+ | -------- | | +---+ +---+ |MNN| |MR2| +---+ +---+ | -------- | | +---+ +---+ |MNN| |MR3| +---+ +---+ | --------- | | +---+ +----+ |MNN| |MNN1| +---+ +----+ Figure 1: An example of nested Mobile Network Using the basic NEMO concept, the traffic flow in Figure 1 between an MMN and CN will be required to go through all the HAs of the MRs along the path. The path will therefore be as shown in Figure 2. 1 2 3 4 3 2 1 MNN1 --- MR3 --- MR2 --- MR1 --- MR1_HA --- MR2_HA --- MR3_HA --- CN Note: The digits represent the number of IPv6 headers. Figure 2: The Traffic Flow Path between MNN1 and CN Although such an arrangement allows MNNs to reach and be reached always by any node on the Internet, ultimately, a host of problems arise for the nested moving networks and their connected MNNs, as discussed in [3,4]. Expires April 2007 3 Internet Draft Optimized Routing in Nested NEMO October 2006 This draft describes a new mechanism to change the way in which nested moving networks operate thereby optimizing the performance of nested moving networks, while considering the afore mentioned problems and additionally making it worthwhile to implement such a structure. This solution leads to the reduced use of tunnels, reduced communication delays, eliminating the visiting nodes’ traffic to other MRs’ home networks and limiting the number of traversed networks. 2 Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC-2119. This document uses the following terms: Home Agent (HA) As defined in [2]. Correspondent Node (CN) As defined in [2]. Mobile Router (MR) As defined in [2]. Mobile Network Node (MNN) As defined in [2]. Visiting Mobile Node (VMN) As defined in [2]. Top Level Mobile Router (TLMR) A Mobile Router that has a point of attachment directly to the Internet or an operator network, and provides the connectivity to other Visiting Mobile Nodes. Home Address (HoA) As defined in [5]. Care-Of Address (CoA) As defined in [5]. Binding Update (BU) Mobile IP signaling with the purpose of establishing or updating a mobility binding. Routing Header (RH) A routing header may be present as an IPv6 header extension, and indicates that the payload has to be delivered to a destination IPv6 address in some way that is different from what would be carried out by standard Internet routing. In Expires April 2007 4 Internet Draft Optimized Routing in Nested NEMO October 2006 this document, use of the term "routing header" typically refers to use of a type 0 and 5 routing header. 3. Protocol Overview The basic idea is to reduce the overheads of the tunneling and the delay of traffic toward all Home Agents (HAs) in nested NEMO. An additional constraint that is considered is the restriction that all traffic related to different networks travel through their home networks, without utilizing standard Mobile IP route optimization mechanisms. This restriction is highly relevant for MNO environments where the MNOs would require that all traffic traverse through the respective MNOs network. Therefore, this means that within this mechanism it is assumed that the traffic of each MR shall go through its home network. This solution extends the functionality of a MR when it acts as a Top Level Mobile Router (TLMR) where it switches between the source address/destination address and routing headers for outgoing/incoming packets respectively. Any packet destined to any node has the same header length regardless of the location of the node in the hierarchy. The outgoing packets from a node located in any level inside the mobile network will go only through the node’s home agent (HA). Another assumption of this solution is that the routing protocol inside nested NEMO is an ad hoc networking (MANET) protocol. Figure 3 illustrates this solution. +--+ +------+ oooooo>|CN|