TEAS Working Group Y. Lee (Editor) Internet Draft Dhruv Dhody Intended Status: Standard Track Huawei D. Ceccarelli Ericsson Takuya Miyasaka KDDI Peter Park KT Bin Young Yoon ETRI Expires: April 28, 2017 October 29, 2016 A Yang Data Model for ACTN VN Operation draft-lee-teas-actn-vn-yang-02 Abstract This document provides a YANG data model for the Abstraction and Control of Traffic Engineered (TE) networks (ACTN) Virtual Network (VN) operation. 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." 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 Lee, et al. Expires April 2017 [Page 1] Internet-Draft ACTN VN YANG Model October 2016 This Internet-Draft will expire on April 29, 2017. Copyright Notice Copyright (c) 2016 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. Table of Contents 1. Introduction...................................................2 1.1. Terminology...............................................3 2. ACTN CMI context...............................................3 2.1. Multi-sources and multi-destinations......................7 3. ACTN VN YANG Model (Tree Structure)............................8 4. ACTN-VN YANG Code.............................................11 5. Security Considerations.......................................22 6. IANA Considerations...........................................23 7. Acknowledgments...............................................23 8. References....................................................24 8.1. Normative References.....................................24 8.2. Informative References...................................24 9. Contributors..................................................24 Authors' Addresses...............................................25 1. Introduction This document provides a YANG data model for the Abstraction and Control of Traffic Engineered (TE) networks (ACTN) Virtual Network (VN) operation that is going to be implemented for the Customer Network Controller (CNC)- Multi-Domain Service Coordinator (MSDC) interface (CMI). Lee, et al. Expires April 2017 [Page 2] Internet-Draft ACTN VN YANG Model October 2016 The YANG model on the CMI is also known as customer service model in [Service-YANG]. The YANG model discussed in this document is used to operate customer-driven VNs during the VN computation, VN instantiation and its life-cycle operations stages. Note that the YANG model presented in this draft has two aspects: - VN pre-instantiation mode of operation (also known as VN compute); - VN instantiation mode of operation. The VN pre-instantiation mode of operation is concerned about service inquiry before making a formal request for VN instantiation. This operation is important for a customer to make sure the network can provide VN services it desires. The VN instantiation mode of operation is concerned about instantiating VNs. In the VN instantiation mode, the CNC provides the VN service definition that includes VN members, VN service objective, VN service policy and preferences, etc. Upon receipt of a VN instantiation request, the MDSC (in coordination with PNCs) executes service request into network operation that include creating tunnels/paths and securing network resources/slices for VNs. The YANG model discussed in this document basically provides the characteristics of VNs such as VN level parameters (e.g., VN ID, VN member, VN objective function, VN service preference, etc.), customer's end point characteristics (e.g., Customer Interface Capability, Access Points Interface characteristics, etc.), and other relevant VN information that needs to be known to the MDSC to facilitate ACTN VN operation. 1.1. Terminology Refer to [ACTN-Frame] and [RFC7926] for the key terms used in this document. 2. ACTN CMI context The model presented in this document has the following ACTN context. Lee, et al. Expires April 2017 [Page 3] Internet-Draft ACTN VN YANG Model October 2016 +-------+ | CNC | +-------+ | | <--- CMI (CNC-MDSC Interface) | +-----------------------+ | MDSC | +-----------------------+ Figure 1. ACTN CMI As defined in [ACTN-FW], a Virtual Network is a client view (typically a network slice) of the transport network. It can be presented by the provider as a set of physical and/or abstracted resources. Depending on the agreement between client and provider various VN operations and VN views are possible. a) VN can be seen as an (or set of) e2e tunnel(s) from a customer point of view where an e2e tunnel is referred as a VN member. Each VN member (i.e., e2e tunnel) can then be formed by recursive aggregation of lower level paths at a provider level. Such end to end tunnels may comprise of customer end points, access links, intra domain paths and inter-domain link. In this view VN is thus a list of VN members. b) VN can also be seen as a terms of topology comprising of physical and abstracted nodes and links. The nodes in this case include physical customer end points, border nodes, and internal nodes as well as abstracted nodes. Similarly the links includes physical access, inter-domain and intra-domain links as well as abstracted links. The abstracted nodes and links in this view can be pre-negotiated or created dynamically. For both cases, the CNC can dynamically add VN elements. For case 1, the VN element is an end-to-end tunnel and for case 2, the VN element can be virtual nodes or virtual links. In the subsequent discussion, the first form of VN will be discussed. Lee, et al. Expires April 2017 [Page 4] Internet-Draft ACTN VN YANG Model October 2016 The following figure describes a VN that comprises three VN members forming a full mesh for the VN as an illustration. VN Member 1 |<-------------------------------------->| | | | ------------- | | ( ) | | - - | +---+ X ( Provider ) Z +---+ |CE1|---+----( )---+---|CE2| +---+ AP1 ( Network ) AP2 +---+ .- - - _ -. |\ ( ) /| \ ------------- / \ | / ---- + AP3 ---- VN Member 2 \ | / VN Member 3 \ Y | / \ +---+ / `----> |CE3|<----` +---+ Figure 2. Full Mesh Example for a VN In Figure 2, a VN has three members, namely, VN Member 1, VN member 2, and VN member 3. VN Member 1 is an end-to-end tunnel identified by CE1-AP1 (source) and CE2-AP2 (destination). Similarly, VN Member 2 by CE1-AP1 and CE3-AP3 and VN Member 3 by CE3-AP3 and CE2-AP2. This particular VN shown in Figure 2 is a full mesh connectivity across these three customer end-points. Lee, et al. Expires April 2017 [Page 5] Internet-Draft ACTN VN YANG Model October 2016 The set of assumptions that applies to this document is the following: - CNC is responsible for providing necessary Customer End-Points information to the MDSC via the CMI. - The access links (between Customer Edge (CE) Devices and the Provider Edge (PE) Devices) are assumed to have been provisioned prior to the VN instantiation request. Access point identifiers have been configured and therefore are known in both the CNC and the MDSC. It is also possible for the customer to create a VN which can be a hub and spoke or any other form of connectivity depending on its connectivity requirement. Each end-to-end tunnel may be unidirectional or bidirectional which is also depending on its connectivity requirements. The following figure shows some examples of a VN that can be represented in a different connectivity form depending on the customer's connectivity requirements. +---+ +---+ +---+ +---+ +---+ +---+ |CE1|---------|CE2| |CE4|---------|CE5| |CE8|---------|CE9| +---+ +---+ +---+ +---+ +---+ +---+ \ / | \ | \ | \ / | \ | \ | \ / | \ | \ | \ / | \ | \ | \ / | \ | \ | \ / | \ | \ | +---+ +---+ +---+ +---+ +---+ |CE3| |CE6| |CE7| |CE6|---------|CE7| +---+ +---+ +---+ +---+ +---+ (a) Full Mesh (b) Hub and Spoke (c) partial Mesh Figure 3. Different Connectivity Forms of a VN It is important to note that a VN can associate a multiple number of end-to-end tunnels (i.e., VN members) with one unique identifier. From a customer standpoint, this simplifies its VN operation significantly. Lee, et al. Expires April 2017 [Page 6] Internet-Draft ACTN VN YANG Model October 2016 The MDSC interacts with the CNC for the VN operation. Once the customer VN is requested by the CNC to the MDSC, the MDSC shall be responsible for translating and mapping the VN request into specific network centric-models (e.g., TE-tunnels [TE-Tunnel], TE-topology [TE-TOPO], etc.) to coordinate the multi-domain network operations with PNCs. 2.1. Multi-sources and multi-destinations In creating a virtual network, the list of sources or destinations or both may not be pre-determined by the customer. For instance, for a given source, there may be a list of multiple-destinations to which the optimal destination may be chosen depending on the network resource situations. Likewise, for a given destination, there may also be multiple-sources from which the optimal source may be chosen. In some cases, there may be a pool of multiple sources and destinations from which the optimal source-destination may be chosen. The following YANG module is shown for describing source container and destination container. See details in Section 4. Lee, et al. Expires April 2017 [Page 7] Internet-Draft ACTN VN YANG Model October 2016 +--rw actn | +--rw vn | +--rw vn-list* [vn-id] | ... | | +--rw src | | | +--rw src? -> /actn/ap/access-point- list/access-point-id | | | +--rw src-vn-ap-id? uint32 | | | +--rw multi-src? boolean | | +--rw dest | | +--rw dest? -> /actn/ap/access- point-list/access-point-id | | +--rw dest-vn-ap-id? uint32 | | +--rw multi-dest? boolean +--ro actn-state +--ro vn +--ro vn-list* [vn-id] | +--ro src | | +--ro src? -> /actn/ap/access-point- list/access-point-id | | +--ro src-vn-ap-id? uint32 | | +--ro multi-src? boolean | +--ro dest | | +--ro dest? -> /actn/ap/access- point-list/access-point-id | | +--ro dest-vn-ap-id? uint32 | | +--ro multi-dest? boolean ... +--ro multi-src-dest | +--ro selected-vn-member? -> /actn-state/vn/vn- list/vn-id 3. ACTN VN YANG Model (Tree Structure) module: ietf-actn-vn +--rw actn | +--rw ap | | +--rw access-point-list* [access-point-id] | | +--rw access-point-id uint32 | | +--rw access-point-name? string | | +--rw max-bandwidth? decimal64 | | +--rw avl-bandwidth? decimal64 | +--rw vn Lee, et al. Expires April 2017 [Page 8] Internet-Draft ACTN VN YANG Model October 2016 | +--rw vn-list* [vn-id] | +--rw vn-id uint32 | +--rw vn-name? string | +--rw vn-member-list* [vn-member-id] | | +--rw vn-member-id uint32 | | +--rw src | | | +--rw src? -> /actn/ap/access-point-list/access- point-id | | | +--rw src-vn-ap-id? uint32 | | | +--rw multi-src? boolean | | +--rw dest | | +--rw dest? -> /actn/ap/access-point-list/access- point-id | | +--rw dest-vn-ap-id? uint32 | | +--rw multi-dest? boolean | +--rw objective-function? pcep:objective-function | +--rw metric* [metric-type] | | +--rw metric-type identityref | | +--rw limit | | | +--rw enabled? boolean | | | +--rw value? uint32 | | +--rw optimize | | +--rw enabled? boolean | | +--rw value? uint32 | +--rw bandwidth? decimal64 | +--rw protection? identityref | +--rw local-reroute? boolean | +--rw push-allowed? boolean | +--rw incremental-update? boolean | +--rw admin-status? identityref +--ro actn-state +--ro ap | +--ro access-point-list* [access-point-id] | +--ro access-point-id uint32 | +--ro access-point-name? string | +--ro max-bandwidth? decimal64 | +--ro avl-bandwidth? decimal64 +--ro vn +--ro vn-list* [vn-id] +--ro vn-id uint32 +--ro vn-name? string +--ro vn-member-list* [vn-member-id] | +--ro vn-member-id uint32 | +--ro src | | +--ro src? -> /actn/ap/access-point-list/access- point-id | | +--ro src-vn-ap-id? uint32 | | +--ro multi-src? boolean | +--ro dest Lee, et al. Expires April 2017 [Page 9] Internet-Draft ACTN VN YANG Model October 2016 | | +--ro dest? -> /actn/ap/access-point-list/access- point-id | | +--ro dest-vn-ap-id? uint32 | | +--ro multi-dest? boolean | +--ro metric* [metric-type] | | +--ro metric-type identityref | | +--ro limit | | | +--ro enabled? boolean | | | +--ro value? uint32 | | +--ro optimize | | +--ro enabled? boolean | | +--ro value? uint32 | +--ro oper-status? identityref | +--ro tunnel-ref? te:tunnel-ref +--ro multi-src-dest | +--ro selected-vn-member? -> /actn-state/vn/vn-list/vn-id +--ro vn-topology-ref | +--ro provider-id-ref? -> /nw:networks/network[nw:network-id = current()/../network-id-ref]/tet:te/provider-id | +--ro client-id-ref? -> /nw:networks/network[nw:network-id = current()/../network-id-ref]/tet:te/client-id | +--ro te-topology-id-ref? -> /nw:networks/network[nw:network-id = current()/../network-id-ref]/tet:te/te-topology-id | +--ro network-id-ref? -> /nw:networks/network/network-id +--ro objective-function? pcep:objective-function +--ro metric* [metric-type] | +--ro metric-type identityref | +--ro limit | | +--ro enabled? boolean | | +--ro value? uint32 | +--ro optimize | +--ro enabled? boolean | +--ro value? uint32 +--ro bandwidth? decimal64 +--ro protection? identityref +--ro local-reroute? boolean +--ro push-allowed? boolean +--ro incremental-update? boolean +--ro admin-status? identityref +--ro oper-status? identityref rpcs: +---x vn-compute +---w input | +---w vn-member-list* [vn-member-id] | | +---w vn-member-id uint32 | | +---w src | | | +---w src? -> /actn/ap/access-point-list/access-point-id | | | +---w src-vn-ap-id? uint32 | | | +---w multi-src? boolean Lee, et al. Expires April 2017 [Page 10] Internet-Draft ACTN VN YANG Model October 2016 | | +---w dest | | +---w dest? -> /actn/ap/access-point-list/access-point- id | | +---w dest-vn-ap-id? uint32 | | +---w multi-dest? boolean | +---w objective-function? pcep:objective-function | +---w metric* [metric-type] | | +---w metric-type identityref | | +---w limit | | | +---w enabled? boolean | | | +---w value? uint32 | | +---w optimize | | +---w enabled? boolean | | +---w value? uint32 | +---w bandwidth? decimal64 | +---w protection? identityref | +---w local-reroute? boolean | +---w push-allowed? boolean | +---w incremental-update? boolean +--ro output +--ro vn-member-list* [vn-member-id] | +--ro vn-member-id uint32 | +--ro src | | +--ro src? -> /actn/ap/access-point-list/access-point-id | | +--ro src-vn-ap-id? uint32 | | +--ro multi-src? boolean | +--ro dest | | +--ro dest? -> /actn/ap/access-point-list/access-point- id | | +--ro dest-vn-ap-id? uint32 | | +--ro multi-dest? boolean | +--ro metric* [metric-type] | | +--ro metric-type identityref | | +--ro limit | | | +--ro enabled? boolean | | | +--ro value? uint32 | | +--ro optimize | | +--ro enabled? boolean | | +--ro value? uint32 | +--ro oper-status? identityref +--ro multi-src-dest +--ro selected-vn-member-id? uint32 4. ACTN-VN YANG Code The YANG code is as follows: Lee, et al. Expires April 2017 [Page 11] Internet-Draft ACTN VN YANG Model October 2016 file "ietf-actn-vn@2016-10-29.yang" module ietf-actn-vn { namespace "urn:ietf:params:xml:ns:yang:ietf-actn-vn"; prefix "vn"; /* Import TE generic types */ import ietf-te-types { prefix "te-types"; } import ietf-te-topology { prefix "tet"; } import ietf-te { prefix "te"; } import ietf-pcep { prefix "pcep"; } organization "IETF Traffic Engineering Architecture and Signaling (TEAS) Working Group"; contact "Editor: Young Lee "; description "This module contains a YANG module for the ACTN VN. It describes a VN operation module that takes place in the context of the CNC-MDSC Interface (CMI) of the ACTN architecture where the CNC is the actor of a VN Instantiation /modification /deletion."; revision 2016-10-29 { description "initial version."; reference Lee, et al. Expires April 2017 [Page 12] Internet-Draft ACTN VN YANG Model October 2016 "TBD"; } identity path-metric-delay { base te-types:path-metric-type; description "delay path metric"; } identity path-metric-delay-variation { base te-types:path-metric-type; description "delay-variation path metric"; } identity path-metric-loss { base te-types:path-metric-type; description "loss path metric"; } identity path-metric-hop { base te-types:path-metric-type; description "hop path metric"; } /* * Groupings */ grouping access-point{ description "AP related information"; leaf access-point-id { type uint32; description "unique identifier for the referred access point"; } leaf access-point-name { type string; description "ap name"; } Lee, et al. Expires April 2017 [Page 13] Internet-Draft ACTN VN YANG Model October 2016 leaf max-bandwidth { type decimal64 { fraction-digits 2; range "0..max"; } description "max bandwidth of the AP"; } leaf avl-bandwidth { type decimal64 { fraction-digits 2; range "0..max"; } description "available bandwidth of the AP"; } /*add details and any other properties of AP, not associated by a VN CE port, PE port etc. This link may not be in the TE topology model(?) thus reference to that model would be incorrect */ }//access-point grouping vn-member { description "vn-member is described by this container"; leaf vn-member-id { type uint32; description "vn-member identifier"; } container src { description "the source of VN Member"; leaf src { type leafref { path "/actn/ap/access-point-list/access-point-id"; } description "reference to source AP"; } Lee, et al. Expires April 2017 [Page 14] Internet-Draft ACTN VN YANG Model October 2016 leaf src-vn-ap-id{ type uint32; description "vn-ap-id"; } leaf multi-src { type boolean; description "Is source part of multi-source, where only one of the source is enabled"; } } container dest { description "the destination of VN Member"; leaf dest { type leafref { path "/actn/ap/access-point-list/access-point-id"; } description "reference to destination AP"; } leaf dest-vn-ap-id{ type uint32; description "vn-ap-id"; } leaf multi-dest { type boolean; description "Is destination part of multi-destination, where only one of the destination is enabled"; } } }//vn-member grouping policy { description "policy related to vn-member-id"; leaf local-reroute { type boolean; Lee, et al. Expires April 2017 [Page 15] Internet-Draft ACTN VN YANG Model October 2016 description "Policy to state if reroute can be done locally"; } leaf push-allowed { type boolean; description "Policy to state if changes can be pushed to the customer"; } leaf incremental-update { type boolean; description "Policy to allow only the changes to be reported"; } }//policy grouping metrics { description "metric related information"; list metric{ key "metric-type"; description "The list of metrics for VN"; leaf metric-type { type identityref { base te-types:path-metric-type; } description "The VN metric type."; } container limit { description "Limiting contraints"; leaf enabled{ type boolean; description "Limit contraint is enabled"; } leaf value{ type uint32; description "The limit value"; } Lee, et al. Expires April 2017 [Page 16] Internet-Draft ACTN VN YANG Model October 2016 } container optimize{ description "optimizing constraints"; leaf enabled{ type boolean; description "Metric to optimize"; } leaf value{ type uint32; description "The computed value"; } } } } grouping service-metric { description "service-metric"; leaf objective-function { type pcep:objective-function; description "operational state of the objective function"; } uses metrics; leaf bandwidth { type decimal64 { fraction-digits 2; range "0..max"; } description "bandwidth requested/required for vn-member-id"; } leaf protection { type identityref { Lee, et al. Expires April 2017 [Page 17] Internet-Draft ACTN VN YANG Model October 2016 base te-types:lsp-prot-type; } description "protection type."; } uses policy; }//service-metric /* * Configuration data nodes */ container actn { description "actn is described by this container"; container ap { description "AP configurations"; list access-point-list { key "access-point-id"; description "access-point identifier"; uses access-point{ description "access-point information"; } } } container vn { description "VN configurations"; list vn-list { key "vn-id"; description "a virtual network is identified by a vn-id"; leaf vn-id { type uint32; description "a unique vn identifier"; } leaf vn-name { type string; Lee, et al. Expires April 2017 [Page 18] Internet-Draft ACTN VN YANG Model October 2016 description "vn name"; } list vn-member-list{ key "vn-member-id"; description "List of VN-members in a VN"; uses vn-member; } uses service-metric; leaf admin-status { type identityref { base te-types:state-type; } default te-types:state-up; description "VN administrative state."; } }//vn-list }//vn }//actn /* * Operational data nodes */ container actn-state{ config false; description "actn is described by this container"; container ap { description "AP state"; list access-point-list { key "access-point-id"; description "access-point identifier"; uses access-point{ description "access-point information"; } } Lee, et al. Expires April 2017 [Page 19] Internet-Draft ACTN VN YANG Model October 2016 } container vn { description "VN state"; list vn-list { key "vn-id"; description "a virtual network is identified by a vn-id"; leaf vn-id { type uint32; description "a unique vn identifier"; } leaf vn-name { type string; description "vn name"; } list vn-member-list{ key "vn-member-id"; description "List of VN-members in a VN"; uses vn-member; uses metrics; leaf oper-status { type identityref { base te-types:state-type; } description "VN-member operational state."; } leaf tunnel-ref { type te:tunnel-ref; description "A reference to the TE tunnel in the TE model"; } } container multi-src-dest{ description "The selected VN Member when multi-src and/or mult-destination is enabled."; leaf selected-vn-member{ type leafref { path "/actn-state/vn/vn-list/vn-id"; Lee, et al. Expires April 2017 [Page 20] Internet-Draft ACTN VN YANG Model October 2016 } description "The selected VN Member along the set of source and destination configured with multi-source and/or multi-destination"; } } container vn-topology-ref{ description "An optional reference to the TE Topology Model where the abstract nodes and links of the Topology can be found"; uses tet:te-topology-ref; } uses service-metric; leaf admin-status { type identityref { base te-types:state-type; } description "VN administrative state."; } leaf oper-status { type identityref { base te-types:state-type; } description "VN operational state."; } }//vn-list }//vn }//actn-state /* * Notifications - TBD */ /* * RPC */ rpc vn-compute{ description "The VN computation without actual instantiation"; input { list vn-member-list{ Lee, et al. Expires April 2017 [Page 21] Internet-Draft ACTN VN YANG Model October 2016 key "vn-member-id"; description "List of VN-members in a VN"; uses vn-member; } uses service-metric; } output { list vn-member-list{ key "vn-member-id"; description "List of VN-members in a VN"; uses vn-member; uses metrics; leaf oper-status { type identityref { base te-types:state-type; } description "VN-member operational state."; } } container multi-src-dest{ description "The selected VN Member when multi-src and/or mult-destination is enabled."; leaf selected-vn-member-id{ type uint32; description "The selected VN Member-id from the input"; } } } } } 5. Security Considerations TDB Lee, et al. Expires April 2017 [Page 22] Internet-Draft ACTN VN YANG Model October 2016 6. IANA Considerations TDB 7. Acknowledgments This document was prepared using 2-Word-v2.0.template.dot. Lee, et al. Expires April 2017 [Page 23] Internet-Draft ACTN VN YANG Model October 2016 8. References 8.1. Normative References [TE-TOPO] X. Liu, et al., "YANG Data Model for TE Topologies", work in progress: draft-ietf-teas-yang-te-topo. [TE-tunnel] T. Saad, et al., "A YANG Data Model for Traffic Engineering Tunnels and Interfaces", work in progress: draft-ietf-teas-yang-te. [Service-YANG] Q. Wu, W. Liu and A. Farrel, "Service Models Explained", draft-wu-opsawg-service-model-explained, work in progress. 8.2. Informative References [RFC7926] A. Farrel (Ed.), "Problem Statement and Architecture for Information Exchange between Interconnected Traffic- Engineered Networks", RFC 7926, July 2016. [ACTN-REQ] Lee, et al., "Requirements for Abstraction and Control of TE Networks", work in progress: draft-ietf-teas-actn- requirements. [ACTN-FWK] D. Ceccarelli, Y. Lee [Editors], "Framework for Abstraction and Control of Traffic Engineered Networks", work in progress: draft-ceccarelli-teas-actn-framework. 9. Contributors Contributor's Addresses Haomian Zheng Huawei Technologies Email: zhenghaomian@huawei.com Xian Zhang Huawei Technologies Email: zhang.xian@huawei.com Lee, et al. Expires April 2017 [Page 24] Internet-Draft ACTN VN YANG Model October 2016 Sergio Belotti Nokia Email: sergio.belotti@nokia.com Authors' Addresses Young Lee (ed.) Huawei Technologies Email: leeyoung@huawei.com Dhruv Dhody Huawei Technologies Email: dhruv.ietf@gmail.com Daniele Ceccarelli Ericsson Torshamnsgatan,48 Stockholm, Sweden Email: daniele.ceccarelli@ericsson.com Takuya Miyasaka KDDI Email: ta-miyasaka@kddi.com Peter Park KT Email: peter.park@kt.com Bin Yeong Yoon ETRI Email: byyun@etri.re.kr Lee, et al. Expires April 2017 [Page 25]