Network Working Group T. Suzuki Internet-Draft Hitachi, Ltd. Intended status: Informational July 6, 2015 Expires: January 7, 2016 Use-case and Requirements for Multi-domain Operation Plane Change draft-suzuki-teas-actn-multidomain-opc-00 Abstract This document provides a use-case and requirements that address the need for facilitating dynamic change of an operation plane, which includes virtually prepared multiple networks and/or data transmission paths, from a current operation one to a backup one during scheduled maintenance or an emergency such as a network disaster. Specifically, the necessity of interfaces to establish consistent end-to-end data transmission paths over multiple domain networks is addressed. 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 January 7, 2016. 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 Suzuki Expires January 7, 2016 [Page 1] Internet-Draft Multi-domain Operation Plane Change July 2015 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. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 4 3. Use Case . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Requirement for Interface of operation plane change system . . 7 4.1. Type I: Direct control interface between DNCs . . . . . . 7 4.2. Type II: Indirect control interface through MDNC . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 7. Informative References . . . . . . . . . . . . . . . . . . . . 13 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 14 Suzuki Expires January 7, 2016 [Page 2] Internet-Draft Multi-domain Operation Plane Change July 2015 1. Introduction This draft provides a use case and requirements that address the necessity of a dynamic change of an operation plane, which includes virtually prepared multiple networks and/or data transmission paths, from a current operation one to a backup one through cooperation between inter domain networks during scheduled maintenance or an emergency such as a network disaster. Networks have become indispensable in daily life, as reflected in the popularity of cloud services provided by way of networks, such as the Internet. Therefore, highly reliable end-to-end data transmission services must be provided. In addition, even if network facilities are extensively damaged due to a natural disaster, data transmission services must be promptly restored. To meet these requirements, a highly reliable packet transport network, such as the Multi-Protocol Label Switching - Transport Profile (MPLS-TP) network, is needed and may be used to transmit data between not only countries but also data centers. In conventional packet transport network management, a data transmission path protection function is used for promptly recovering from a small network failure, such as a node or link failure. However, the path protection is not always usable in a network disaster. Plenty of data transmission paths are calculated sequentially after a network disaster is detected. As a result, much time is needed to calculate all the paths. In another case, multiple path configurations will be changed for maintenance to add, delete, and check network resources. Therefore, a novel network management scheme is needed to change plenty of path configurations instantaneously from the current operation plane to the backup one. Related documents are the ACTN-framework [ACTN-Framework], the problem statement [ACTN-Problem] and the requirements [ACTN-Requirement]. Section 2 discusses specific issues on the prompt changing of network configurations. Section 3 describes a use case for an inter-domain network management system. Section 4 prescribes requirements that the system needs to satisfy. Suzuki Expires January 7, 2016 [Page 3] Internet-Draft Multi-domain Operation Plane Change July 2015 2. Problem Statement There are two major techniques for recovering from network failures: protection and restoration. In protection, a backup data transmission path for a current one is calculated and set up before network operations are started. When a data transmission failure is detected, a data transmission path is changed from the current path to the backup one. In restoration, the backup path is not physically prepared in advance. When a data transmission failure is detected, a new data transmission path is calculated and/or set up. Then data are transmitted through the newly set up data path. In a network disaster due to an earthquake, for example, protection paths might not be useful for some situations. When the protection paths are not useful, another backup path should be calculated. If there are plenty of current data transmission paths, calculating the backup paths takes an enormous amount of time. In the same way, a huge amount of time is needed to calculate and to set up plenty of paths for restoration. Enhancement of protection is envisaged as a new recovery procedure from a network disaster. Specifically, a concept of a virtual operation plane is adopted. The virtual operation plane includes multiple data transmission paths, and so does the current operation plane. In contrast, a recovery operation plane includes multiple backup data transmission paths. In the new recovery procedure, multiple backup operation planes are prepared in advance. When a network disaster is detected, the most suitable backup operation plane is selected and configurations for recovery are distributed to data transmission nodes. In addition, a network system must be able to change plenty of path configurations instantaneously when it adds or deletes network resources or stops using resources to execute maintenance. The system explained above can be easily managed if there is only one management server. However, if the network is composed of multiple domains and there are multiple management servers, coordinated network disaster recovery procedures are not easy to execute. Therefore, a cooperative management scheme for recovering from a network disaster is needed. Suzuki Expires January 7, 2016 [Page 4] Internet-Draft Multi-domain Operation Plane Change July 2015 3. Use Case A target operation plane change system through cooperation of multiple domain controller servers is shown in Figure 1. The whole network is composed of multiple domain networks such as domain-A and domain-B physical networks. Each domain has a domain network controller server. In addition, each domain network is composed of multiple packet transport nodes. An end-to-end data transmission path is managed through cooperation between domain network controller servers. Each domain network controller server calculates multiple current data transmission paths and manages them as one current operation plane. In addition, the controller server calculates multiple backup operation planes and controls them in the case of a network disaster. For example, the domain-A network controller server prepares a backup operation plane, plane-A1, on the basis of the assumption of network failures or maintenance. Plane-A1 includes multiple data transmission paths or virtual networks. The domain-B network controller server prepares another backup operation plane, plane-B1, to connect data transmission paths to plane-A1 of the domain-A network. On the other hand, the domain-B network controller server prepares another backup operation plane, plane-B2, on the basis of the assumption of other network failures or maintenance. The domain-A network controller server prepares another backup operation plane, plane-A2, to connect data transmission paths to plane-B2 of the domain-B network. When the domain-A network controller server changes the operation plane from the current operation one to plane-A1 during the network operation, it transmits an identifier of plane-A1 to the domain-B network controller server to show a change of the operation plane of the domain-A network controller server. After receiving the identifier of plane-A1, the domain-B network controller server changes the operation plane from the current one to plane-B1. To develop the above-mentioned system, two interfaces must be created. One maintains consistency of the end-to-end data transmission paths between domains in the backup operation plane. Specifically, this interface needs to transmit information of the backup operation planes including multiple data transmission paths from one domain network controller server to another. The other domain network controller server can then calculate backup operation planes in accordance with the received backup operation plane information. The other interface is used for transmitting the identifier to change the operation plane from one domain network controller server to another. Suzuki Expires January 7, 2016 [Page 5] Internet-Draft Multi-domain Operation Plane Change July 2015 +--------------------+ +--------------------+ | Domain-A network | | Domain-B network | | controller server | | controller server | +---------+----------+ +---------+----------+ | | | | +------------+-------------+ +-----------+--------------+ | | | | | +--------------------+ | | +--------------------+ | | | Current +----------+ Current | | | | operation plane +----------+ operation plane | | | | A0 +----------+ B0 | | | +--------------------+ | | +--------------------+ | | | | | | ======================== | | ======================== | | | | | | +--------------------+ | | +--------------------+ | | | Backup +----------+ Backup | | | | operation plane +----------+ operation plane | | | | A1 +----------+ B1 | | | +--------------------+ | | +--------------------+ | | | | | | +--------------------+ | | +--------------------+ | | | Backup +----------+ Backup | | | | operation plane +----------+ operation plane | | | | A2 +----------+ B2 | | | +--------------------+ | | +--------------------+ | | - | | - | | - | | - | | - | | - | | +--------------------+ | | +--------------------+ | | | Backup +----------+ Backup | | | | operation plane +----------+ operation plane | | | | An +----------+ Bn | | | +--------------------+ | | +--------------------+ | | | | | +--------------------------+ +--------------------------+ Domain-A physical network Domain-B physical network Figure 1: Example of target operation plane change system Suzuki Expires January 7, 2016 [Page 6] Internet-Draft Multi-domain Operation Plane Change July 2015 4. Requirement for Interface of operation plane change system There are two types of control structures. One is a direct communication type between domain network controllers (DNCs) as shown in Figure 2. The other is an indirect communication type through a multi-domain network controller (MDNC) as shown in Figure 3. To realize an operation plane change system, the interfaces shown in either figure must be defined. 4.1. Type I: Direct control interface between DNCs The interfaces shown in Figure 2 must be prepared to execute consistent changing of operation planes to establish end-to-end data transmission paths between multiple domain networks for network disaster recovery or maintenance. The requirements for each interface are briefly described below. (I-1) Interface for preparing backup operation planes: This interface is used to prepare consistent backup operation planes through cooperation between DNCs. For example, the domain-A network controller (DNC-A) prepares multiple backup operation planes as shown in Figure 1 for the current operation plane composed of multiple data transmission paths. A backup operation plane is prepared for each assumed network failure or maintenance. The DNC-A transmits "information of sharing paths for each link between domain networks" and "the identifier of a backup operation plane" to the domain-B network controller (DNC-B) when it attempts to change the operation plane to recover from a network disaster or to execute maintenance. When the DNC-B controller receives them, it prepares a backup operation plane for each received DNC-A backup plane to establish consistent data transmission paths. In addition, configurations of prepared backup operation planes are stored. (I-2) Interface for requesting change of operation plane: This interface is used to send a change request of the operation plane from the current one to the backup one when a DNC detects a network disaster or starts to execute maintenance. For example, when the DNC-A detects a network disaster, it determines the most suitable backup operation plane and starts management in accordance with the configurations of the selected operation plane. In addition, the DNC-A transmits "the identifier of the backup operation plane" to the DNC-B to establish consistent end-to-end paths when it changes the operation plane. When the DNC-B receives the identifier of the backup operation plane, it changes the operation plane from the current one to the backup one specified by the received identifier. In addition, information Suzuki Expires January 7, 2016 [Page 7] Internet-Draft Multi-domain Operation Plane Change July 2015 of the time to change path configurations is exchanged through this interface between DNCs. +--------------------+ (I-1)I/F +--------------------+ | Domain-A network | (I-2)I/F | Domain-B network | | controller (DNC-A) |<--------->| controller (DNC-B) | +---------+----------+ +---------+----------+ | | | | +------------+-------------+ +------------+-------------+ | +-----+ | | Domain-A +-----+ Domain-B | | physical network +-----+ physical network | +--------------------------+ +--------------------------+ Links Figure 2: Control structure type I 4.2. Type II: Indirect control interface through MDNC In the case of the type II control communication structure, the interfaces shown in Figure 3 must be prepared to execute consistent changing of operation planes to establish end-to-end data transmission paths between multiple domain networks for network disaster recovery or maintenance. The requirements for each interface are briefly described below. (II-1) Interface to MDNC for preparing backup operation planes: This interface is used to prepare consistent backup operation planes through cooperation between DNCs through the MDNC. For example, the DNC-A prepares multiple backup operation planes for the current operation plane composed of multiple data transmission paths. A backup operation plane is prepared for each assumed network failure or maintenance. The DNC-A transmits "information of sharing paths for each link between domains" and "the identifier of a backup operation plane" to the MDNC in order to send the information to the DNC-B as a final destination. (II-2) Interface to MDNC for requesting change of operation plane: This interface is used to send a change of the operation plane from the current one to the backup one when a DNC detects a network disaster or starts to execute maintenance. For Suzuki Expires January 7, 2016 [Page 8] Internet-Draft Multi-domain Operation Plane Change July 2015 example, when the DNC-A detects a network disaster, it determines the most suitable backup operation plane and starts management in accordance with the configurations of the selected operation plane. In addition, the DNC-A transmits "the identifier of the backup operation plane" to the MDNC to establish consistent end-to-end paths in order to send the identifier to the DNC-B as a final destination. (II-3) Interface to DNC for preparing backup operation planes: This interface is used to prepare consistent backup operation planes by cooperation between DNCs through the MDNC. For example, the MDNC transmits received "information of sharing paths for each link between domains" and "the identifier of a backup operation plane" to the DNC-B. When the DNC-B receives them, it prepares a backup operation plane for each received DNC-A backup plane to establish consistent data transmission paths. In addition, configurations of prepared backup operation planes are stored. (II-4) Interface to DNC for requesting change of operation plane: This interface is used to send a change of the operation plane from the current one to the backup one. For example, the MDNC transmits received "the identifier of the backup operation plane" to the DNC-B. When the DNC-B receives the identifier, it changes the operation plane from the current one to the backup one specified by the received identifier. In addition, information of the time to change path configurations is sent through this interface from the MDNC to the DNC-B. Suzuki Expires January 7, 2016 [Page 9] Internet-Draft Multi-domain Operation Plane Change July 2015 +-----------------------------------------------------+ | Multi-domain network controller (MDNC) | +------------------------------------------+----------+ ^ | :(II-1)I/F |(II-3)I/F :(II-2)I/F |(II-4)I/F : v +--------------------+ +--------------------+ | Domain-A network | | Domain-B network | | controller (DNC-A) | | controller (DNC-B) | +---------+----------+ +---------+----------+ | | | | +------------+-------------+ +------------+-------------+ | +-----+ | | Domain-A +-----+ Domain-B | | physical network +-----+ physical network | +--------------------------+ +--------------------------+ Links Figure 3: Control structure type II Suzuki Expires January 7, 2016 [Page 10] Internet-Draft Multi-domain Operation Plane Change July 2015 5. Security Considerations This document describes problems and requirements for network disaster recovery or maintenance through cooperation between domain management functions or servers. The system might be composed of multiple management functions to manage each domain network, and each management function might be implemented in different computational equipment. To achieve network disaster recovery through coordination between multiple network domains, information must be exchanged between them. Therefore, a secure communication channel needs to be used between the domain management functions. Suzuki Expires January 7, 2016 [Page 11] Internet-Draft Multi-domain Operation Plane Change July 2015 6. IANA Considerations This document includes no request for IANA. Suzuki Expires January 7, 2016 [Page 12] Internet-Draft Multi-domain Operation Plane Change July 2015 7. Informative References [ACTN-Framework] Ceccarelli, D., Lee, Y., Fang, L., Lopez, D., Belotti, S., King, D., and D. Dhoddy, "Framework for Abstraction and Control of Transport Networks", June 2015. [ACTN-Problem] Lee, Y., King, D., Boucadair, M., Jing, R., and L. Murillo, "Problem Statement for Abstraction and Control of Transport Networks", June 2015. [ACTN-Requirement] Lee, Y., Belotti, S., Pithewan, K., and D. Ceccarelli, "Requirements for Abstraction and Control of Transport Networks", April 2015. Suzuki Expires January 7, 2016 [Page 13] Internet-Draft Multi-domain Operation Plane Change July 2015 Author's Address Toshiaki Suzuki Research & Development Group, Hitachi, Ltd. 292 Yoshida-cho Totsuka-ku, Yokohama, Kanagawa 244-0817 Japan Phone: +81-50-3135-3066 Email: toshiaki.suzuki.cs@hitachi.com Suzuki Expires January 7, 2016 [Page 14]