DMM WG Younghan Kim Internet Draft Soongsil University Intended status: Standard Track Seil Jeon, Ed. Expires: April 27, 2015 Institute de Telecomunicacoes October 27, 2014 Enhanced Mobility Anchoring in Distributed Mobility Management draft-yhkim-dmm-enhanced-anchoring-00.txt Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on April 27, 2015. Copyright Notice Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Jeon et al. Expires April 27, 2015 [Page 1] Internet-Draft Enhanced Anchoring in DMM October 2014 Abstract This document presents a new perspective for the solution design of enhanced mobility anchoring in a distributed mobility management deployment. Mobility anchor function is composed of forwarding statement management and forwarding path management functions. In this draft, enhanced mobility anchoring solution design is discussed in the two cases: co-located forwarding state and path management functions on the same network entity and separated forwarding state and path management functions on different network entities. Table of Contents 1. Introduction ................................................ 2 2. Conventions and Terminology ................................. 3 3. Cases ....................................................... 3 3.1. Case 1: Co-located forwarding state and path management functions on the same network entity (MR) ................... 3 3.2. Case 2: Separated forwarding state and path management functions on different network entities ..................... 4 4. Security Considerations ..................................... 5 5. IANA Considerations ......................................... 5 6. References .................................................. 6 6.1. Normative References ................................... 6 6.2. Informative References ................................. 6 1. Introduction This document presents a new perspective for the solution design of enhanced mobility anchoring in a distributed mobility management deployment. [RFC 7333] defines the requirements for distributed mobility management (DMM), in order to fundamentally address the scalability issues derived from a centralized mobility management (CMM) deployment. Based on the given requirements, there may have diverse design solutions for enhancing mobility anchoring, depending on a view point looking at mobility anchor function. Mobility anchor is composed of forwarding statement management and forwarding path management functions, where the former is responsible for creating and managing binding cache management while the latter is responsible for managing the forwarding paths using such as tunneling or non-tunneling interface. Each function can be co-located on a same network entity or separated on different Jeon et al. Expires April 27, 2015 [Page 2] Internet-Draft Enhanced Anchoring in DMM October 2014 network entities for flexible deployment or efficient network operation. With the granularity of specified mobility anchor function, enhanced mobility anchoring solution design is discussed. 2. Conventions and 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 [RFC2119]. Mobility router (MR) denotes a network entity, which has mobility access and anchor functionality. Additionally, we use the following term: Forwarding state management function (FSMF): is responsible for creating and managing a binding cache entry, until the terminal's session/flow is closed. Forwarding path management function (FPMF): is responsible for managing forwarding path using a tunnel or non-tunnel interface, to forward the packet destined to an assigned IP or prefix. The forwarding rule should be obtained from FSMF and is managed stateless. 3. Cases 3.1. Case 1: Co-located forwarding state and path management functions on the same network entity (MR) ------------- PBU ------------- | (MR) | -----------------> | (MR) | | FSMF + FPMF | <----------------- | FSMF + FPMF | ------------- PBA ------------- | | | (indication) | | | ------ | MN | ------ Jeon et al. Expires April 27, 2015 [Page 3] Internet-Draft Enhanced Anchoring in DMM October 2014 Figure 1 Co-located FSMF and FPMF model In this case, FSM and FPM are co-located at MRs. When an MN is attached at an MR, the MR should be able to assign IP prefix on its address pool and manage binding cache associated with the assigned IP prefix. When anchor switching is needed (for load-balancing or optimal routing after the MN's handover), the MR (left) initiates an anchor switching procedure, sending Proxy Binding Update (PBU) signaling message including the forwarding state associated with the MN's flow to another MR (right) as shown in Figure 1. In [PMIP.MSR], an anchor switching mechanism was proposed with the name of mobility session redirection, over a Proxy Mobile IPv6 (PMIPv6) domain, specifying signaling and associated operation for LMA switching. It may belong to this case, though it follows centralized mobility management. In this case, each MR should be involved in negotiation for anchor switching and have a target MR selection algorithm, which leads to more signaling and complex processing. 3.2. Case 2: Separated forwarding state and path management functions on different network entities ---------------------- | FSMF (Controller) | ---------------------- | | | | | | PBU| |PBA PBA| |PBU | | ---------- ---------- | FPMF (MR)| | FPMF (MR)| ---------- ---------- | | | (indication) | | | ------ | MN | ------ Figure 2 Separated FSMF and FPMF model In this case, MRs have the forwarding path management function only. There is a dedicated and centralized network entity working as a Jeon et al. Expires April 27, 2015 [Page 4] Internet-Draft Enhanced Anchoring in DMM October 2014 controller for anchor switching, as well as being in charge of IP or prefix assignment and management of binding cache entry. When an MN enters a distributed mobility management domain, it accesses FSM to get a new IP or prefix, which can be determined based on attached location of the MR. The assigned IP or prefix is delivered to the requested MR, and the MR then applies the received IP or prefix to the forwarding table. When anchor switching is needed, there are no signaling interactions between the former MR and new MR but between the related MRs and controller, since the controller is in charge of the anchor switching operation. As shown in Figure 2, the requesting MR (left) sends PBU signaling message, defined in [RFC5213], to controller with the forwarding state associated with the MN. The controller then checks an available MR (or based on a designated MR received from the requesting MR), and delivers the forwarding state to an MR (right). The MR (right) applies the forwarding rule between the MRs by sending PBU signaling message and sends back a PBA signaling message by the reverse path. For smooth path transition during the anchor switching, a transient tunneling could be established between the two MRs until a new routing path is established. When the routing path is made, the forwarding table applied in the previous MR is deleted. This deployment makes MRs lightweight for anchor switching, controlled by a central entity managing forwarding state and monitoring load status at each MR. 4. Security Considerations T.B.D. 5. IANA Considerations T.B.D. Jeon et al. Expires April 27, 2015 [Page 5] Internet-Draft Enhanced Anchoring in DMM October 2014 6. References 6.1. Normative References [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC7333] H. Chan, D. Liu, P. Seite, H. Yokota, and J. Korhonen, "Requirements for Distributed Mobility Management," IETF RFC 7333, Aug. 2014. [RFC5213] S. Gundavelli, K. Leung, V. Devarapalli, K. Chowdury, and B.Patil, "Proxy Mobile IPv6," IETF RFC 5213, Aug. 2008. 6.2. Informative References [PMIP.MSR]S. Jeon and Y. Kim, "Proxy Mobile IPv6 with Mobility Session Redirection," draft-sijeon-netext-pmip-msr-01, Jul. 2014. Jeon et al. Expires April 27, 2015 [Page 6] Internet-Draft Enhanced Anchoring in DMM October 2014 Authors' Addresses Younghan Kim Soongsil University 369, Sangdo-ro, Dongjak-gu, Seoul 156-743, Korea younghak@ssu.ac.kr Seil Jeon (Editor) Instituto de Telecomunicacoes Campus Universitario de Santiago Aveiro 3810-193, Portugal seiljeon@av.it.pt Jeon et al. Expires April 27, 2015 [Page 7]