--- 1/draft-ietf-pce-applicability-actn-04.txt 2018-03-05 10:13:47.962957867 -0800 +++ 2/draft-ietf-pce-applicability-actn-05.txt 2018-03-05 10:13:48.006958906 -0800 @@ -1,21 +1,21 @@ PCE Working Group D. Dhody Internet-Draft Y. Lee Intended status: Informational Huawei Technologies Expires: September 6, 2018 D. Ceccarelli Ericsson March 5, 2018 Applicability of Path Computation Element (PCE) for Abstraction and Control of TE Networks (ACTN) - draft-ietf-pce-applicability-actn-04 + draft-ietf-pce-applicability-actn-05 Abstract Abstraction and Control of TE Networks (ACTN) refers to the set of virtual network (VN) operations needed to orchestrate, control and manage large-scale multi-domain TE networks so as to facilitate network programmability, automation, efficient resource sharing, and end-to-end virtual service aware connectivity and network function virtualization services. @@ -63,31 +63,31 @@ 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Path Computation Element (PCE) . . . . . . . . . . . . . 2 1.1.1. Role of PCE in SDN . . . . . . . . . . . . . . . . . 3 1.1.2. PCE in multi-domain and multi-layer deployments . . . 4 1.2. Abstraction and Control of TE Networks (ACTN) . . . . . . 4 1.3. PCE and ACTN . . . . . . . . . . . . . . . . . . . . . . 6 2. Architectural Considerations . . . . . . . . . . . . . . . . 6 2.1. Multi domain coordination via Hierarchy . . . . . . . . . 6 2.2. Virtualization/Abstraction function . . . . . . . . . . . 7 2.3. Customer mapping function . . . . . . . . . . . . . . . . 8 - 2.4. Virtual Network Operations . . . . . . . . . . . . . . . 8 + 2.4. Virtual Network Operations . . . . . . . . . . . . . . . 9 3. Interface Considerations . . . . . . . . . . . . . . . . . . 9 - 4. Realizining ACTN with PCE (and PCEP) . . . . . . . . . . . . 10 - 5. Relationship to PCE based central control . . . . . . . . . . 13 - 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 - 7. Security Considerations . . . . . . . . . . . . . . . . . . . 13 - 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13 - 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 + 4. Realizing ACTN with PCE (and PCEP) . . . . . . . . . . . . . 10 + 5. Relationship to PCE based central control . . . . . . . . . . 14 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 14 + 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14 + 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 9.1. Normative References . . . . . . . . . . . . . . . . . . 14 - 9.2. Informative References . . . . . . . . . . . . . . . . . 14 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 + 9.2. Informative References . . . . . . . . . . . . . . . . . 15 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 1. Introduction 1.1. Path Computation Element (PCE) The Path Computation Element Communication Protocol (PCEP) [RFC5440] provides mechanisms for Path Computation Elements (PCEs) [RFC4655] to perform path computations in response to Path Computation Clients (PCCs) requests. @@ -326,23 +326,36 @@ to IGPs and BGP flooding, using PCEP itself. The child PCE can use this mechanism to transport Link-State and TE information from child PCE to a Parent PCE using PCEP. In ACTN, there is a need to control the level of abstraction based on the deployment scenario and business relationship between the controllers. The mechanism used to disseminate information from PNC (child PCE) to MDSC (parent PCE) should support abstraction. [I-D.lee-teas-actn-abstraction] describes a few alternative approaches of abstraction. The resulting abstracted topology can be - encoded using the PCEP-LS mechanisms [I-D.dhodylee-pce-pcep-ls]. - PCEP-LS is an attractive option when the operator would wish to have - a single control plane protocol (PCEP) to achieve ACTN functions. + encoded using the PCEP-LS mechanisms [I-D.dhodylee-pce-pcep-ls] and + its optical network extension [I-D.lee-pce-pcep-ls-optical]. PCEP-LS + is an attractive option when the operator would wish to have a single + control plane protocol (PCEP) to achieve ACTN functions. + + [I-D.ietf-teas-actn-framework] discusses two ways to build abstract + topology from an MDSC standpoint with interaction with PNCs. The + primary method is called authomatic generation of abstract topology + by configuration. with this method, automatic generation is based on + the abstraction/summarization of the whole domain by the PNC and its + advertisement on the MPI. The seconday method is called on-demand + generation of supplementary topology via Path Compute Request/Reply. + This method may be needed to obtain further complementary information + such as potential connectivity from child PCEs in order to facilitate + an end-to-end path provisioning. PCEP is well suited to support both + methods. 2.3. Customer mapping function In ACTN, there is a need to map customer virtual network (VN) requirements into network provisioning request to the PNC. That is, the customer requests/commands are mapped into network provisioning requests that can be sent to the PNC. Specifically, it provides mapping and translation of a customer's service request into a set of parameters that are specific to a network type and technology such that network configuration process is made possible. @@ -414,24 +427,26 @@ responsible for its domain control. o In case of hierarchy of MDSC, the MPI is applied recursively. From an abstraction point of view, the top level MDSC which interfaces the CNC operates on a higher level of abstraction (i.e., less granular level) than the lower level MSDCs. PCEP is especially suitable on the MPI as it meets the requirement and the functions as set out in the ACTN framework [I-D.ietf-teas-actn-framework]. Its recursive nature is well suited - via the multi-level hierarchy of PCE. The Section 4 describe how PCE - and PCEP could help realize ACTN. + via the multi-level hierarchy of PCE. PCEP can also be applied to + the CMI as the CNC can be a path computation client while the MDSC + can be a path computation server. The Section 4 describe how PCE and + PCEP could help realize ACTN on the MPI. -4. Realizining ACTN with PCE (and PCEP) +4. Realizing ACTN with PCE (and PCEP) As per the example in the Figure 2, there are 4 domains, each with its own PNC and a MDSC at top. The PNC and MDSC need PCE as a important function. The PNC (or child PCE) already uses PCEP to communicate to the network device. It can utilize the PCEP as the MPI to communicate between controllers too. ****** ..........*MDSC*.............................. . ****** .. MPI . @@ -742,20 +757,27 @@ O. Dios, "Applicability of the Path Computation Element to Inter-Area and Inter-AS MPLS and GMPLS Traffic Engineering", draft-ietf-pce-inter-area-as- applicability-06 (work in progress), July 2016. [I-D.dhodylee-pce-pcep-ls] Dhody, D., Lee, Y., and D. Ceccarelli, "PCEP Extension for Distribution of Link-State and TE Information.", draft- dhodylee-pce-pcep-ls-10 (work in progress), March 2018. + [I-D.lee-pce-pcep-ls-optical] + Lee, Y., zhenghaomian@huawei.com, z., Ceccarelli, D., + weiw@bupt.edu.cn, w., Park, P., and B. Yoon, "PCEP + Extension for Distribution of Link-State and TE + information for Optical Networks", draft-lee-pce-pcep-ls- + optical-04 (work in progress), February 2018. + [I-D.leedhody-pce-vn-association] Lee, Y., Dhody, D., Zhang, X., and D. Ceccarelli, "PCEP Extensions for Establishing Relationships Between Sets of LSPs and Virtual Networks", draft-leedhody-pce-vn- association-04 (work in progress), February 2018. [I-D.litkowski-pce-state-sync] Litkowski, S., Sivabalan, S., and D. Dhody, "Inter Stateful Path Computation Element communication procedures", draft-litkowski-pce-state-sync-02 (work in