Teas Working Group Young Lee Internet Draft Huawei Intended status: Informational Sergio Belotti Alcatel-Lucent Expires: April 2016 Dhruv Dhody Huawei Daniele Ceccarelli Ericsson Bin Young Yun ETRI October 5, 2015 Information Model for Abstraction and Control of TE Networks (ACTN) draft-leebelotti-teas-actn-info-01.txt Abstract This draft provides an information model for abstraction and control of Traffic Engineered (TE) networks (ACTN). 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 Lee-Belotti Expires April 5, 2016 [Page 1] Internet-Draft ACTN Info Model March 2015 The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 5, 2015. Copyright Notice Copyright (c) 2015 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...................................................3 2. ACTN Common Interfaces Information Model.......................4 2.1. VN Action Primitives......................................5 2.1.1. VN Instantiate.......................................5 2.1.2. VN Modify............................................6 2.1.3. VN Delete............................................6 2.1.4. VN Path Compute......................................6 2.1.5. VN Query.............................................6 2.1.6. VN Update............................................6 2.2. VN Objects................................................7 2.2.1. VN Identifier........................................7 2.2.2. VN Topology Metric...................................7 2.2.3. Traffic Matrix.......................................8 2.2.4. VN Survivability.....................................9 2.2.5. VN Status...........................................10 2.2.6. VN Topology.........................................10 2.2.7. VN Connectivity Topology............................10 2.2.8. VN Service Policy...................................10 3. References....................................................11 3.1. Informative References...................................11 4. Contributors..................................................12 Contributors' Addresses..........................................12 Lee-Belotti Expires April 5, 2016 [Page 2] Internet-Draft ACTN Info Model March 2015 Authors' Addresses...............................................12 Appendix A: ACTN Applications....................................13 A.1. Coordination of Multi-destination Service Requirement/Policy.........................................13 A.2. Application Service Policy-aware Network Operation....15 A.3. Network Function Virtualization Service Enabled Connectivity...............................................17 A.4. Dynamic Service Control Policy Enforcement for Performance and Fault Management...........................19 A.5. E2E VN Survivability and Multi-Layer (Packet-Optical) Coordination for Protection/Restoration....................20 1. Introduction This draft provides an information model for the requirements identified in the ACTN requirements [ACTN-Req] and the ACTN interfaces identified in the ACTN architecture and framework document [ACTN-Frame]. The purpose of this draft is to put all information elements of ACTN in one place before proceeding to development work necessary for protocol extensions and data models. The ACTN reference architecture identified a three-tier control hierarchy as depicted in Figure 1: - Customer Network Controllers (CNC) - Multi-Domain Service Coordinator (MDSC) - Physical Network Controllers (PNC). +-------+ +-------+ +-------+ | CNC-A | | CNC-B | | CNC-C | +-------+ +-------+ +-------+ \___________ | ____________ _/ ---------- | CMI ------------ \ | / +-----------------------+ | MDSC | +-----------------------+ _________/ | \_________ -------- | MPI ------------____ / | \ +-------+ +-------+ +-------+ | PNC | | PNC | | PNC | +-------+ +-------+ +-------+ Lee-Belotti Expires April 5, 2016 [Page 3] Internet-Draft ACTN Info Model March 2015 Figure 1: A Three-tier ACTN control hierarchy The two interfaces with respect to the MDSC, one north of the MDSC and the other south of the MDSC are referred to as CMI (CNC-MDSC Interface) and MPI (MDSC-PNC Interface), respectively. It is intended to model these two interfaces and derivative interfaces thereof (e.g., MDSC to MSDC in a hierarchy of MDSCs) with one common model. Appendix A provides some relevant ACTN use-cases extracted from [ACTN-Req]. Appendix A is information only and may help readers understand the context of key use-cases addressed in [ACTN-Req]. 2. ACTN Common Interfaces Information Model This section provides ACTN common interface information model to describe in terms of primitives, objects, their properties (represented as attributes), their relationships, and the resources for the service applications needed in the ACTN context. Basic primitives (messages) are required between the CNC-MDSC and MDSC-PNC controllers. These primitives can then be used to support different ACTN network control functions like network topology request/query, VN service request, path computation and connection control, VN service policy negotiation, enforcement, routing options, etc. The standard interface is described between a client controller and a server controller. A client-server relationship is recursive between a CNC and a MDSC and between a MDSC and a PNC. In the CMI, the client is a CNC while the server is a MDSC. In the MPI, the client is a MDSC and the server is a PNC. There may also be MDSC- MDSC interface(s) that need to be supported. This may arise in a hierarchy of MDSCs in which workloads may need to be partitioned to multiple MDSCs. At a minimum, the following VN action primitives should be supported: - VN Instantiate (See Section 2.1.1. for the description) Lee-Belotti Expires April 5, 2016 [Page 4] Internet-Draft ACTN Info Model March 2015 - VN Modify (See Section 2.1.2. for the description) - VN Delete (See Section 2.1.3. for the description) - VN Query (See Section 2.1.4. for the description) - VN Path Compute (See Section 2.1.4. for the description) - VN Update ((See Section 2.1.5. for the description) The functionality below will be supported as part of already defined primitives as above. - Security negotiation - Local Domain path computation (related to PNC - Coordination of multi-destination () 2.1. VN Action Primitives This section provides a list of main primitives necessary to satisfy ACTN requirements specified in [ACTN-REQ]. describes main primitives. VN Action can be one of the following primitives: (i) instantiate; (ii) modify; (iii) delete; (iv) path compute; (v) query; (vi) update. ::= | | | | | 2.1.1. VN Instantiate refers to an action from customers/applications to request their VNs. This primitive can also be applied from an MDSC to a PNC requesting a VN (if the domain the PNC supports can instantiate the entire VN) or a part of VN elements. Lee-Belotti Expires April 5, 2016 [Page 5] Internet-Draft ACTN Info Model March 2015 2.1.2. VN Modify refers to an action from customers/applications to modify an existing VN (i.e., instantiated VN). This primitive can also be applied from an MDSC to a PNC requesting a VN (if the domain the PNC supports can instantiate the entire VN) or a part of VN elements. 2.1.3. VN Delete refers to an action from customers/applications to delete an existing VN. This primitive can also be applied from an MDSC to a PNC requesting a VN (if the domain the PNC supports can instantiate the entire VN) or a part of VN elements. 2.1.4. VN Path Compute refers to an action from customers/applications to request a VN path computation. This primitive can also be applied from an MDSC to a PNC requesting a VN (if the domain the PNC supports can instantiate the entire VN) or a part of VN elements. This is to be differentiated from a VN Instantiate. The purpose of VN Path Compute is a priori exploration to estimate network resources availability before making a VN instantiate decision. Obviously an abstracted view of network resources topology is needed to permit this function. This action is also necessary for an MDSC to PNCs in determining end-to-end multi-domain paths. VN Instantiate may also trigger an MDSC for a VN Path Compute to lower-level PNCs in order to determine end-to-end paths that comprise of a VN. 2.1.5. VN Query refers to any query pertaining to the VN that has been already instantiated. VN Query fulfills a pull model and permit to get topology view. 2.1.6. VN Update refers to any update to the VN that need to be updated to the subscribers. VN Update fulfills a push model. Lee-Belotti Expires April 5, 2016 [Page 6] Internet-Draft ACTN Info Model March 2015 There are other existing and upcoming TE mechanisms to fulfill the same function as VN Update. VN Update can be built on these other existing TE mechanisms. The details are TDB. [Editor's Note: The mapping of VN Primitives and their VN Objects will be provided in the future revision.] 2.2. VN Objects This section provides a list of objects associated with VN action primitives. 2.2.1. VN Identifier is an identifier that identifies a unique VN. 2.2.2. VN Topology Metric describes the requirements/preferences of VNs that customers/applications want to instantiate. ::= [] [] Where ::= | describes if the request is . a single vs. a bulk request, Lee-Belotti Expires April 5, 2016 [Page 7] Internet-Draft ACTN Info Model March 2015 . Multiple VN diversity in case of a bulk request, whether VNs should be disjoint or not), . Single VN diversity (node/link disjoint) . Others TBD. indicates a higher level of objective function applied to the VN level, for computing a path vector.VN is comprised of a set of paths and each one of these needs an objective function. 2.2.3. Traffic Matrix describes connectivity-level attributes that need to be conveyed by the CNC to MDSC or the MDSC to PNCs. ::= Where ::= ( [] [])... It is assumed that a list of interface identifiers has been known to the server prior to any VN actions. The Client Capability comprises the client interface capability (e.g., maximum interface bandwidth, etc.). indicates if an End-point is source or not. ::= | | | Lee-Belotti Expires April 5, 2016 [Page 8] Internet-Draft ACTN Info Model March 2015 ::= [] [] [] 2.2.4. VN Survivability describes all attributes related with the VN protection level and its survivability policy enforced by the customers/applications. ::= Where ::= | <1+1> | <1:N> ::= [] Where is a delegation policy to the Server to allow or not a local reroute fix upon a failure of the primary LSP. is only applied on the MPI where the MDSC (client) provides a domain preference to each PNC (server). Lee-Belotti Expires April 5, 2016 [Page 9] Internet-Draft ACTN Info Model March 2015 is a policy that allows a server to trigger an updated VN topology upon failure without an explicit request from the client. Push action can be set as default unless otherwise specified. is another policy that triggers an incremental update from the server since the last period of update. Incremental update can be set as default unless otherwise specified. 2.2.5. VN Action Status is the status indicator whether the VN has been successfully instantiated, modified, or deleted in the server network or not in response to a particular VN action. 2.2.6. VN Topology describes VN topology. Details of are TBD. VN Topology can be defined using existing TE mechanisms. Details are TBD. 2.2.7. VN Connectivity Topology describes the instantiated VN property. Details are TBD. [Editor's Note: This may be combined with .] 2.2.8. VN Service Preference ::= Lee-Belotti Expires April 5, 2016 [Page 10] Internet-Draft ACTN Info Model March 2015 Where describes the End-Point Location's support for certain Virtual Network Functions (VNFs) (e.g., security function, firewall capability, etc.). describes any preference related to Virtual Network Service (VNS) that application/client can enforce via CNC towards lower level controllers. For example, permission the correct selection from the network of the destination related to the indicated VNF It is e.g. the case of VM migration among data center and CNC can enforce specific policy that can permit MDSC/PNC to calculate the correct path for the connectivity supporting the data center interconnection required by application. describes if the End- Point can support load balancing, disaster recovery or VM migration and so can be part of the selection by MDSC following service Preference enforcement by CNC. 3. References 3.1. Informative References [ACTN-Req] Y. Lee, et al., "Requirements for Abstraction and Control of Transport Networks", draft-lee-teas-actn-requirements, work in progress. [ACTN-Frame] D. Ceccarelli, et al., "Framework for Abstraction and Control of Transport Networks", draft-ceccarelli-teas- actn-framework, work in progress. Lee-Belotti Expires April 5, 2016 [Page 11] Internet-Draft ACTN Info Model March 2015 4. Contributors Contributors' Addresses Authors' Addresses Young Lee (Editor) Huawei Technologies 5340 Legacy Drive Plano, TX 75023, USA Phone: (469)277-5838 Email: leeyoung@huawei.com Sergio Belotti (Editor) Alcatel Lucent Via Trento, 30 Vimercate, Italy Email: sergio.belotti@alcatel-lucent.com Dhruv Dhoddy Huawei Technologies, Divyashree Technopark, Whitefield Bangalore, India Email: dhruv.ietf@gmail.com Daniele Ceccarelli Ericsson Torshamnsgatan,48 Stockholm, Sweden Email: daniele.ceccarelli@ericsson.com Bin Young Yun ETRI Email: byyun@etri.re.kr Haomian Zheng Huawei Technologies Email: zhenghaomian@huawei.com Xian Zhang Huawei Technologies Email: zhang.xian@huawei.com Lee-Belotti Expires April 5, 2016 [Page 12] Internet-Draft ACTN Info Model March 2015 Appendix A: ACTN Applications A.1. Coordination of Multi-destination Service Requirement/Policy +----------------+ | CNC | | (Global DC | | Operation | | Control) | +--------+-------+ | | Service Requirement/Policy: | | - Endpoint/DC location info | | - Endpoint/DC dynamic | | selection policy | | (for VM migration, DR, LB) | v +---------+---------+ | Multi-domain | Service policy-driven |Service Coordinator| dynamic DC selection +-----+---+---+-----+ | | | | | | +----------------+ | +----------------+ | | | +-----+-----+ +-----+------+ +------+-----+ | PNC for | | PNC for | | PNC for | | Transport | | Transport | | Transport | | Network A | | Network B | | network C | +-----------+ +------------+ +------------+ | | | +---+ ------ ------ ------ +---+ |DC1|--//// \\\\ //// \\\\ //// \\\\---+DC5| +---+ | | | | | | +---+ | TN A +-----+ TN B +----+ TN C | / | | | | | / \\\\ //// / \\\\ //// \\\\ //// +---+ ------ / ------ \ ------ \ |DC2| / \ \+---+ +---+ / \ |DC6| +---+ \ +---+ +---+ |DC3| \|DC4| +---+ +---+ DR: Disaster Recovery LB: Load Balancing Figure A.1: Service Policy-driven Data Center Selection Lee-Belotti Expires April 5, 2016 [Page 13] Internet-Draft ACTN Info Model March 2015 Figure A.1 shows how VN service policies from the CNC are incorporated by the MDSC to support multi-destination applications. Multi-destination applications refer to applications in which the selection of the destination of a network path for a given source needs to be decided dynamically to support such applications. Data Center selection problems arise for VM mobility, disaster recovery and load balancing cases. VN's service policy plays an important role for virtual network operation. Service policy can be static or dynamic. Dynamic service policy for data center selection may be placed as a result of utilization of data center resources supporting VNs. The MDSC would then incorporate this information to meet the service objective of this application. Lee-Belotti Expires April 5, 2016 [Page 14] Internet-Draft ACTN Info Model March 2015 A.2. Application Service Policy-aware Network Operation +----------------+ | CNC | | (Global DC | | Operation | | Control) | +--------+-------+ | | Application Service Policy | | - VNF requirement (e.g. | | security function, etc.) | | - Location profile for each VNF | v +---------+---------+ | Multi-domain | Dynamically select the |Service Coordinator| network destination to +-----+---+---+-----+ meet VNF requirement. | | | | | | +---------------+ | +----------------+ | | | +------+-----+ +-----+------+ +------+-----+ | PNC for | | PNC for | | PNC for | | Transport | | Transport | | Transport | | Network A | | Network B | | network C | | | | | | | +------------+ +------------+ +------------+ | | | {VNF b} | | | {VNF b,c} +---+ ------ ------ ------ +---+ |DC1|--//// \\\\ //// \\\\ //// \\\\-|DC5| +---+ | | | | | |+---+ | TN A +---+ TN B +--+ TN C | / | | | | | / \\\\ //// / \\\\ //// \\\\ //// +---+ ------ / ------ \ ------ \ |DC2| / \ \\+---+ +---+ / \ |DC6| {VNF a} +---+ +---+ +---+ |DC3| |DC4| {VNF a,b,c} +---+ +---+ {VNF a, b} {VNF a, c} Figure A.2: Application Service Policy-aware Network Operation Lee-Belotti Expires April 5, 2016 [Page 15] Internet-Draft ACTN Info Model March 2015 This scenario is similar to the previous case in that the VN service policy for the application can be met by a set of multiple destinations that provide the required virtual network functions (VNF). Virtual network functions can be, for example, security functions required by the VN application. The VN service policy by the CNC would indicate the locations of a certain VNF that can be fulfilled. This policy information is critical in finding the optimal network path subject to this constraint. As VNFs can be dynamically moved across different DCs, this policy should be dynamically enforced from the CNC to the MDSC and the PNCs. Lee-Belotti Expires April 5, 2016 [Page 16] Internet-Draft ACTN Info Model March 2015 A.3. Network Function Virtualization Service Enabled Connectivity +----------------+ | CNC | | (Global DC | | Operation | | Control) | +--------+-------+ | | Service Policy related to VNF | | (e.g., firewall, traffic | | optimizer) | | | v +---------+---------+ | Multi-domain | Select network |Service Coordinator| connectivity subject to +-----+---+---+-----+ meeting service policy | | | | | | +---------------+ | +----------------+ | | | +------+-----+ +-----+------+ +------+-----+ | PNC for | | PNC for | | PNC for | | Transport | | Transport | | Transport | | Network A | | Network B | | network C | | | | | | | +------------+ +------------+ +------------+ | | | | | | +---+ ------ ------ ------ +---+ |DC1|--//// \\\\ //// \\\\ //// \\\\-|DC5| +---+ | | | | | |+---+ | TN A +---+ TN B +--+ TN C | / | | | | | / \\\\ //// / \\\\ //// \\\\ //// +---+ ------ / ------ \ ------ \ |DC2| / \ \\+---+ +---+ / \ |DC6| +---+ +---+ +---+ |DC3| |DC4| +---+ +---+ Figure A.3: Network Function Virtualization Service Enabled Connectivity Lee-Belotti Expires April 5, 2016 [Page 17] Internet-Draft ACTN Info Model March 2015 Network Function Virtualization Services are usually setup between customers' premises and service provider premises and are provided mostly by cloud providers or content delivery providers. The context may include, but not limited to a security function like firewall, a traffic optimizer, the provisioning of storage or computation capacity where the customer does not care whether the service is implemented in a given data center or another. The customer has to provide (and CNC is providing this)the type of VNF he needs and the policy associated with it (e.g. metric like estimated delay to reach where VNF is located in the DC). The policy linked to VNF is requested as part of the VN instantiation. These services may be hosted virtually by the provider or physically part of the network. This allows the service provider to hide his own resources (both network and data centers) and divert customer requests where most suitable. This is also known as "end points mobility" case and introduces new concepts of traffic and service provisioning and resiliency (e.g., Virtual Machine mobility). Lee-Belotti Expires April 5, 2016 [Page 18] Internet-Draft ACTN Info Model March 2015 A.4. Dynamic Service Control Policy Enforcement for Performance and Fault Management +------------------------------------------------+ | Customer Network Controller | +------------------------------------------------+ 1.Traffic| /|\4.Traffic | /|\ Monitor& | | Monitor | | 8.Traffic Optimize | | Result 5.Service | | modify & Policy | | modify& | | optimize \|/ | optimize Req.\|/ | result +------------------------------------------------+ | Multi-domain Service Coordinator | +------------------------------------------------+ 2. Path | /|\3.Traffic | /|\ Monitor | | Monitor | |7.Path Request | | Result 6.Path | | modify & | | modify& | | optimize \|/ | optimize Req.\|/ | result +------------------------------------------------+ | Physical Network Controller | +------------------------------------------------+ Figure A.4: Dynamic Service Control for Performance and Fault Management Figure A.4 shows the flow of dynamic service control policy enforcement for performance and fault management initiated by customer per VN. The feedback loop and filtering mechanism tailored for VNs performed by the MDSC differentiates this ACTN scope from traditional network management paradigm. VN level dynamic OAM data model is a building block to support this capability. Lee-Belotti Expires April 5, 2016 [Page 19] Internet-Draft ACTN Info Model March 2015 A.5. E2E VN Survivability and Multi-Layer (Packet-Optical) Coordination for Protection/Restoration +----------------+ | Customer | | Network | | Controller | +--------*-------+ * | E2E VN Survivability Req. * | - VN Protection/Restoration * v - 1+1, Restoration, etc. +------*-----+ - End Point (EP) info. | | | MDSC | MDSC enforces VN survivability | | requirement, determining the | | optimal combination of Packet/ +------*-----+ Optical protection/restoration * Optical bypass, etc. * * ********************************************** * * * * +----*-----+ +----*----+ +----*-----+ +----*----+ |PNC for | |PNC for | |PNC for | |PNC for | |Access N. | |Packet C.| |Optical C.| |Access N.| +----*-----+ +----*----+ +----*-----+ +---*-----+ * --*--- * * * /// \\\ * * --*--- | Packet | * ----*- /// \\\ | Core +------+------/// \\\ | Access +----\\ /// * | Access | | Network | ---+-- * | Network | +---+ |\\\ /// | * \\\ ///---+EP6| | +---+- | | -----* -+---+ +---+ +-+-+ | | +----/// \\\ | | |EP1| | +--------------+ Optical | | | +---+ +---+ | | Core +------+ +--+EP5| +-+-+ \\\ /// +---+ |EP2| ------ | +---+ | | +--++ ++--+ |EP3| |EP4| +---+ +---+ Figure A.5: E2E VN Survivability and Multi-layer Coordination for Protection and Restoration Lee-Belotti Expires April 5, 2016 [Page 20] Internet-Draft ACTN Info Model March 2015 Figure A.5 shows the need for E2E protection/restoration control coordination that involves CNC, MDSC and PNCs to meet the VN survivability requirement. VN survivability requirement and its policy need to be translated into multi-domain and multi-layer network protection and restoration scenarios across different controller types. After an E2E path is setup successfully, the MDSC has a unique role to enforce policy-based flexible VN survivability requirement by coordinating all PNC domains. As seen in Figure A.5, multi-layer (i.e., packet/optical) coordination is a subset of this E2E protection/restoration control operation. The MDSC has a role to play in determining an optimal protection/restoration level based on the customer's VN survivability requirement. For instance, the MDSC needs to interface the PNC for packet core as well as the PNC for optical core and enforce protection/restoration policy as part of the E2E protection/restoration. Neither the PNC for packet core nor the PNC for optical core is in a position to be aware of the E2E path and its protection/restoration situation. This role of the MDSC is unique for this reason. In some cases, the MDSC will have to determine and enforce optical bypass to find a feasible reroute path upon packet core network failure which cannot be resolved the packet core network itself. To coordinate this operation, the PNCs will need to update its domain level abstract topology upon resource changes due to a network failure or other factors. The MDSC will incorporate all these update to determine if an alternative E2E reroute path is necessary or not based on the changes reported from the PNCs. It will need to update the E2E abstract topology and the affected CN's VN topology in real-time. This refers to dynamic synchronization of topology from Physical topology to abstract topology to VN topology. MDSC will also need to perform the path restoration signaling to the affected PNCs whenever necessary. Lee-Belotti Expires April 5, 2016 [Page 21]