Network Working Group N. Vadrevu Internet Draft VN Telecom Consultancy Intended status: Informational D. Zhang Expires: January 2016 Alibaba Group July 23, 2015 Applicability of SUPA draft-vadrevu-supa-applicability-00 Abstract SUPA will define a generic policy information model, an imperative (Event-Condition-Action, ECA) policy information model and a declarative (intent-based) policy information model which is the extension of the generic information model, and a set of policy data models which will make use of the common concepts defined in the information model. This memo will explore some typical use cases and demonstrate the applicability of SUPA policy models. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. 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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. Conventions ................................................. 3 3. Framework ................................................... 3 4. SUPA Model Applicability .................................... 5 4.1. ECA Data Model ......................................... 5 4.1.1. SES Use Case ...................................... 5 4.1.1.1. Scenario ..................................... 5 4.1.1.2. Generic Policy Information Models ............ 7 4.1.1.3. Programmatic approach - SUPA modeling......... 8 4.1.2. DDC Use Case ...................................... 8 4.1.3. Instant VPN ....................................... 8 4.2. Declarative Data Model.................................. 9 5. Security Considerations .................................... 11 6. IANA Considerations ........................................ 11 7. Acknowledgments ............................................ 11 8. References ................................................. 11 8.1. Normative References .................................. 11 8.2. Informative References ................................ 11 xxx Expires January 23, 2016 [Page 2] Internet-Draft SUPA Model Applicability July 2015 Authors' Addresses ............................................ 12 1. Introduction One of the ways for network service automation is using network management and operation software applications. The applications should not directly communicate with each network element; a hierarchical and extensible framework should be considered to hide the protocol specific and/or vendor specific details, high level network and service abstraction, and standardized programming API will be necessary. SUPA will define policy information models and data models, for service management and operation applications. [I-D.strassner-supa- generic-policy-info-model] defines a common set of concepts for various data models which may use different languages, protocols, and repositories. Three information models are defined in [I-D.strassner-supa-generic- policy-info-model]: Generic Policy Information Model (GPIM), Eca Policy Rule Information Model (EPRIM), Logic Statement Information Model (LSIM). The ECA information model is intended for dynamic service automation; while the LSIM is intended for expressing high requirements without being involved in network details. Data models can be defined by developers / operators or by any third party, as long as they follow the common concepts defined in SUPA information model. [I-D.chen-supa-eca-data-model] defines a policy data model of Event-Condition-Action (ECA), which is an example. 2. Conventions 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 RFC-2119 [RFC2119]. 3. Framework xxx Expires January 23, 2016 [Page 3] Internet-Draft SUPA Model Applicability July 2015 +-----------------------------------------------------------------+ | Service Management | | | | +----------------------------------+ | | | Generic Policy Information Model | | | +----+------------------------+----+ | | D R | | D R | | \ / \ / | | +---------------------------+ +-------------------------------+ | | | Generic Policy Data Model | | Service Management Data Model | | | +---------------------------+ +---------------+---------------+ | | / \ / \ | | | | | | | | | +--------------+--------------------------------+-----------------+ | | | NETCONF/RESTCONF | +----+----------------------+----+ C C C C \ / \ / +----------------+-----------+ +-------+--------------------+ | Network Manager/Controller | | Network Manager/Controller | | +--------------------+ | | +---------------------+ | | | Network Resource | | | | Network Resource | | | | Data Model | | | | Data Model | | | +--------------------+ | | +---------------------+ | +---+---+---+----------------+ +-----+---+---+--------------+ / \ / \ / \ / \ / \ / \ C C C C C C C C C C C C C C C C C C \ / \ / \ / \ / \ / \ / NE1 NE2 NEn NE1 NE2 NEn Figure 1 Use of SUPA Models C: Communications xxx Expires January 23, 2016 [Page 4] Internet-Draft SUPA Model Applicability July 2015 D: Derived from R: References (i.e., the information model is used by the system to instantiate the data model). As shown in Figure 1, SUPA will define generic policy information models, which are independent of services and use cases. Policy data models can be derived from the generic information models. The data model will define high level, maybe network-wide policies. Policy data model will be used in conjunction with service data models to generate configurations for network elements. The service data model is use case specific and will be developed by operators or third parties, which is out the scope of SUPA. The service management applications will send SUPA data models to the service management system, where policy making and automated policy enforcement will be performed, and the data models will be mapped to configuration of network elements. Configuration of network elements is vendor specific, using various protocols, such Netconf, Restconf, etc. SUPA also make use of information collected from network elements. The information may include warning or fault event, load status, traffic statistics, etc, which can be used to adjust network configurations. This kind of automation is done through ECA data models. 4. SUPA Model Applicability 4.1. ECA Data Model 4.1.1. SES Use Case 4.1.1.1. Scenario xxx Expires January 23, 2016 [Page 5] Internet-Draft SUPA Model Applicability July 2015 +-----------------------------------------------------------------+ | Service Management | | +----------------------------------+ | | | Generic Policy Information Model | | | +----+------------------------+----+ | | | | +---------------------------+ +-------------------------------+ | | | Generic Policy Data Model | | Service Management Data Model | | | +---------------------------+ +---------------+---------------+ | +-----------------------------------------------------------------+ | | +------------------------------+ | Network Manager / Controller | +------------------------------+ | | +------------------+ +-------------+ | Traffic Analysis | +--------+ | Headquarter |----------| |-------| Site 1 | +-------------+ | WAN Optimization | +--------+ +------------------+ | | +----------+ | Site 2 | +----------+ Figure 2 Switched Ethernet Service Switched Ethernet services (SES) to Small and Medium Businesses business is a growing business segment of the service provider. As the Enterprise's applications grow in demands in terms of the bandwidth and richness of applications, WAN optimization is needed to improve the service quality. SUPA policy data models can be used for maximizing the WAN performance by analyzing the traffic and performing application management and acceleration tools for the network. In the use case below, Service Manager (SM) is used for service and policy definition and Network Manager (Controller) is used for xxx Expires January 23, 2016 [Page 6] Internet-Draft SUPA Model Applicability July 2015 network topology maintenance and mapping data models to detail network configurations. While speed and bandwidth are at the forefront of the WAN Optimization there need to be tools in place to detect, diagnose, remedy and report application performance to ensure the SLAs for a customer are enforced. The service is modeled in terms of what kind of service (Ethernet, VLAN), bandwidth (10Mbps- 10 Gbps), service package (platinum, gold, silver) etc. Policy models are based on an Event condition action like: 1. Bandwidth usage alarm triggers data caching 2. Latency alarm triggers reduction of re transmission 3. WAN outage at a specific site can trigger geographic redundancy (provided the service is setup for GR) The above are 3 of the primitives (Event condition action - ECA) on which the run time operations could be based on. When the service model is comprehensively designed with more possibilities (variables), more policy models could be implemented 4.1.1.2. Generic Policy Information Models Requirements and configurations derived from above application scenarios can be described by service data model and policy data models as below: Service data model can be used to describe attributes for the SES, including service package type (Platinum, gold etc), bandwidth bought by the subscriber (100Mbps, 10Gbps), connection name -copper/ GigE, latency, etc. Policy data model describes a condition when the link capacity reaches 90%, Service prioritization and WAN optimization need to be enforced based on the customers service package. Event is the link utilization and condition is the usage and action is the WAN optimization. The actions could trigger multiple actions like data compression, protocol acceleration (like streaming gets priority) which are beyond the scope of SUPA xxx Expires January 23, 2016 [Page 7] Internet-Draft SUPA Model Applicability July 2015 4.1.1.3. Programmatic approach - SUPA modeling The advantage of the programmatic approach can be maximized by defining as many SUPA ECA models as possible in a top down approach In this use case, since this is a switched service, point to point traffic can be identified (by IP Address and port number) and segmented and whole bandwidth can be utilized by many applications simultaneously. Examples are: Print jobs, backups etc.. The benefit of the SUPA is in creating many policies upfront. As the operations grow in complexity SUPA can expand an existing policy by adding more variables. This is how reusable policies can be developed upfront and configuration and maintenance operations can be dealt by modeling and programmatic approach. 4.1.2. DDC Use Case A data center can provide various services, such as video host, VMs, etc. In order to provide better user experience, the contents may be located in multiple geographically distributed data centers so that the user can get service from a nearby location. The content distribution between data centers is necessary, an example is, for a social video service provider, they need to copy videos uploaded by users to all the data centers. Another example is, cloud operator may needs to migrate VMs from one location to another. This kind of operation usually will require a lot of bandwidth. To avoid consuming too much network resource in the busy hours, it is usually done in the non-busy hours, such as 1 or 2 o'clock in the morning. Example: Event: time of the day Condition: now is Evening Action: Configure a VPN for VM migration for 2 hours 4.1.3. Instant VPN Provide VPN connection for Customer A when receiving a request. xxx Expires January 23, 2016 [Page 8] Internet-Draft SUPA Model Applicability July 2015 (Figure to be added) Traditionally, when an operator needs to deploy VPN service for an enterprise customer, they will send a service staff to the customer site and make the wire connection between the CE and PE; the service staff will also collect the configuration information, e.g. port/frame/slot of PE, PE ID, etc, and then send the information back to the management system, and the management system will configure the network according to this information together with the customer' information (such as bandwidth, SLA, etc). The problem of this approach is that the service staff needs to collect the connection information and feedback to the management system, and MUST make sure the information matches the actual connection. This operation is error prone. New approach should not count on the physical / geographical information feedback by the service staff, minimize the operation procedures. The CE should send authentication (with credentials) request to the PE, and PE should forward the request to the management system together with port/frame/slot on which the request is received, the PE ID etc. Example: Event: receive customer VPN service request Condition: YES (received valid request) Action: Configure VPN service for the customer In the above cases, the advantage of SUPA ECA model is, it can work for different scenarios with a common set of concept: events, conditions, actions, etc. 4.2. Declarative Data Model Logic Statement Information Model (LSIM) can also be called as declarative or intent model. This type of model will describe the service intention without specifying low level details, such xxx Expires January 23, 2016 [Page 9] Internet-Draft SUPA Model Applicability July 2015 protocol level or network device level detail, but just the service requirements itself. Example1: All SNMP agents in my network should drop all SNMP traffic unless it is originating or targeted to the management network The management system will expand this requirement according to the network topology which is provided by other systems, and get a list of all the involved network elements which should be configured. The SNMP traffic can be identified by the TCP/UDP port 161/162; and if the traffic is originating or targeted to management can be identified by the source or destination address or the traffic, but, which is out of scope of SUPA. With the above information, the management system can generate and install configurations to all the related network elements. The administrator does not have to specify any protocol level or network device level details during network management. Example: Virtual DC Request: Create a virtual DC for customer B with specified resource (BW, storage, compute) (Figure to be added) When cloud / DC operator signs a contract with customer, resource information such as network bandwidth, storage size, number of CPU, memory size, etc, will be specified. But in deployment, the resources may be located in multiple distributed data centers, and tunnels will be created to inter- connect these resources, which will make it look like one seamless entity - a virtual DC. There could be quite a number of tunnels, and the tunnels are dynamic, either for the reason of load balancing purpose or VM migration, or other reasons. This will make it difficult to configure the service statically or manually, service automation is very necessary. The service management system will have a repository of available resources, including the topology. And also the management system xxx Expires January 23, 2016 [Page 10] Internet-Draft SUPA Model Applicability July 2015 will have the customer specific information (location, SLA, agreed resources, etc). The administrator can send the service requirement to the management system by a high level data model, which can further be mapped to low level detail data models, then finally mapped to configurations of network devices. 5. Security Considerations Since SUPA models can be used to generate configurations for network elements, the management applications which send models to service management system must go through authentication and authorization. 6. IANA Considerations This memo does not have any requirement to IANA. 7. Acknowledgments This document has benefited from reviews, suggestions, comments and proposed text provided by the following members, listed in alphabetical order: Juergen Schoenwaelder, John,Strassner, James Huang This document was prepared using 2-Word-v2.0.template.dot. 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 8.2. Informative References [I-D.klyus-supa-proposition] Klyus, M., Strassner, J., "SUPA Value Proposition", draft-klyus-supa-proposition-02 (work in progress), July 4, 2015 xxx Expires January 23, 2016 [Page 11] Internet-Draft SUPA Model Applicability July 2015 [I-D.strassner-supa-generic-policy-info-model] Strassner, J., "Generic Policy Information Model for Simplified Use of Policy Abstractions (SUPA)", draft-strassner-supa- generic-policy-info-model-02, July 4, 2015 [I-D.chen-supa-eca-data-model] Chen, M., Contreras L., Fukushima, M., "ECA Policy YANG Data Model", draft-chen-supa-eca-data- model-00 (work in progress), July 2, 2015 [I-D.ww-sfc-control-plane] Li, H., Wu, Q., et al, "Service Function Chaining (SFC) Control Plane Components & Requirements", draft-ww-sfc-control-plane-06 (work in progress), June 8, 2015 Authors' Addresses Narasimha Vadrevu VN Telecom Consultancy Cupertino, California Email: vadrevun@von20.com Dacheng Zhang Alibaba Group
Email: Dacheng.zdc@alibaba-inc.com xxx Expires January 23, 2016 [Page 12]