ForCES WG B. Khasnabish Internet-Draft ZTE TX, Inc. Intended status: Standards Track E. Haleplidis Expires: March 3, 2016 University of Patras J. Hadi Salim, Ed. Mojatatu Networks August 31, 2015 IETF ForCES Logical Function Block (LFB) Subsidiary Management draft-ietf-forces-lfb-subsidiary-management-02 Abstract Deployment experience has demonstrated the value of using the Forwarding and Control Element Separation (ForCES) architecture to manage resources other than packet forwarding. In that spirit, the Forwarding Element Manager (FEM) is modelled by creating a Logical Functional Block (LFB) to represent its functionality. We refer to this LFB as the Subsidiary Mechanism (SM) LFB. A Control Element (CE) that controls a Forwarding Element's (FE) resources can also manage its configuration via the SM LFB. This document introduces the SM LFB class, an LFB class that specifies the configuration parameters of an FE. The configuration parameters include new LFB class loading, CE associations as well as to provide manipulation of debug mechanisms along with a general purpose attribute definition to describe config information. 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 March 3, 2016. Khasnabish, et al. Expires March 3, 2016 [Page 1] Internet-Draft ForCES LFB Subsidiary Management August 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 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 5 1.2. Definitions . . . . . . . . . . . . . . . . . . . . . . . 5 2. Use cases . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.1. High Availability . . . . . . . . . . . . . . . . . . . . 6 2.2. Scalability . . . . . . . . . . . . . . . . . . . . . . . 6 2.3. Adding New Resources To An NE . . . . . . . . . . . . . . 6 2.4. New LFB class installation . . . . . . . . . . . . . . . 6 2.5. Logging Mechanism . . . . . . . . . . . . . . . . . . . . 7 2.6. General Purpose Attribute Definition . . . . . . . . . . 7 3. Applicability statement . . . . . . . . . . . . . . . . . . . 8 3.1. FE Integrated . . . . . . . . . . . . . . . . . . . . . . 8 3.2. Virtual FEs . . . . . . . . . . . . . . . . . . . . . . . 8 4. SM Library . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.1. Frame Definitions . . . . . . . . . . . . . . . . . . . . 8 4.2. Datatype Definitions . . . . . . . . . . . . . . . . . . 8 4.3. Metadata Definitions . . . . . . . . . . . . . . . . . . 9 4.4. SM . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4.4.1. Data Handling . . . . . . . . . . . . . . . . . . . . 9 4.4.2. Components . . . . . . . . . . . . . . . . . . . . . 10 4.4.3. Capabilities . . . . . . . . . . . . . . . . . . . . 10 4.4.4. Events . . . . . . . . . . . . . . . . . . . . . . . 10 5. XML for SM LFB . . . . . . . . . . . . . . . . . . . . . . . 11 6. Security Considerations . . . . . . . . . . . . . . . . . . . 17 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 7.1. LFB Class Names and LFB Class Identifiers . . . . . . . . 17 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 9.1. Normative References . . . . . . . . . . . . . . . . . . 18 9.2. Informative References . . . . . . . . . . . . . . . . . 19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 Khasnabish, et al. Expires March 3, 2016 [Page 2] Internet-Draft ForCES LFB Subsidiary Management August 2015 1. Introduction Deployment experience has demonstrated the value of using the Forwarding and Control Element Separation (ForCES) architecture to manage resources other than packet forwarding. In that spirit, the Forwarding Element Manager (FEM) is modelled by creating a Logical Functional Block (LFB) to represent its functionality. We refer to this LFB as the Subsidiary Mechanism (SM) LFB. A Control Element (CE) that controls a Forwarding Element's (FE) resources can also manage its configuration via the SM LFB. This document introduces the SM LFB class, an LFB that specifies the configuration parameters of an FE. On a running FE, a CE application may update an FE's runtime configuration via the SM LFB instance. Khasnabish, et al. Expires March 3, 2016 [Page 3] Internet-Draft ForCES LFB Subsidiary Management August 2015 ForCES Network Element +-------------------------------------+ | +---------------------+ | | | Control Application | | | +--+--------------+---+ | | | | | | | | | -------------- Fc | -----------+--+ +-----+------+ | | CE Manager |---------+-| CE 1 |------| CE 2 | | -------------- | | | Fr | | | | | +-+---------+-+ +------------+ | | Fl | | | Fp / | | | | +--------+ / | | | | Fp |/ | | | | | | | | | Fp /|----+ | | | | /--------/ | | -------------- Ff | ---+---------- -------------- | | FE Manager |---------+-| FE 1 | Fi | FE 2 | | -------------- | | |------| | | | -------------- -------------- | | | | | | | | | | | ----+--+--+--+----------+--+--+--+----- | | | | | | | | | | | | | | | | Fi/f Fi/f Fp: CE-FE interface Fr: CE-CE interface Fc: Interface between the CE Manager and a CE Ff: Interface between the FE Manager and an FE Fl: Interface between the CE Manager and the FE Manager Fi/f: FE external interface Figure 1: ForCES Architectural Diagram Figure 1 shows a control application manipulating, at runtime, FE config via the SM LFB control. It would appear that that control application is playing the part of the FE Manager thus appears as the messaging for Ff (FEM to FE interface) going via the standard Fp plane. However the SM LFB describes a subset of the operations that can be performed over Ff; it does not suggest moving away from the Ff interface. The SM LFB class describes the configuration parameters of an FE, namely the LFB classes it should load, the CEs it should be associated with as well the respective CE IP addresses. Additionally the SM LFB provides a general purpose attribute definition to Khasnabish, et al. Expires March 3, 2016 [Page 4] Internet-Draft ForCES LFB Subsidiary Management August 2015 describe config information, as well as the ability to manipulate debug logging mechanism. This document assumes that FEs are already booted. The FE's configuration can then be updated at runtime via the SM LFB for runtime config purposes. This document does not specify or standardize the FEM-FE (Ff) interface as depicted in [RFC3746]. This document describes a mechanism with which a CE can instruct the SM for FE management using ForCES. This work item makes no assumption of whether FE resources are physical or virtual. In fact, the LFB library provided here is applicable to both. Thus it can also be useful in addressing control of virtual FEs where individual FEM Managers can be addressed to control the creation, configuration, and resource assignment of such virtual FEs within a physical FE. 1.1. Requirements Language 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 [RFC2119]. 1.2. Definitions This document follows the terminology defined by [RFC3654], [RFC3746], [RFC5810] and [RFC5812]. In particular, the reader is expected to be familiar with the following terms: o Logical Functional Block (LFB) o Forwarding Element (FE) o Control Element (CE) o ForCES Network Element (NE) o FE Manager (FEM) o CE Manager o ForCES Protocol o ForCES Protocol Layer (ForCES PL) o ForCES Protocol Transport Mapping Layer (ForCES TML) Khasnabish, et al. Expires March 3, 2016 [Page 5] Internet-Draft ForCES LFB Subsidiary Management August 2015 2. Use cases In this section we present sample use cases to illustrate the need and usefulness of the SM LFB. All use cases assume that an FE is already booted up and tied to at least one CE. A control application can delete a CE from an FE's table of CEs which instructs the FE to terminate the connection with that removed CE. Likewise, the control application via the master CE instructs an FE to establish a ForCES association with a new CE by adding a particular CE to the FE's CEs table. 2.1. High Availability Assume an FE associated to only one CE. At runtime, a CE management application may request for redundancy reasons that an FE to be associated to another CE as a backup. To achieve this goal, the CE management application specifies the CEID of the new backup CE (to be uniquely identified within the NE) and the CE's IP address (IPv4 or IPv6). 2.2. Scalability Assume an NE cluster that has FEs connected possibly in an active backup setup to multiple CEs. Assume that system analytics discover that the CE is becoming a bottleneck. A new CE could be booted and some FEs moved to it. To achieve this goal, the CE management application will first ask an FE to connect to a new CE and would then instruct that FE to change its master to the new CE as described in [RFC7121]. 2.3. Adding New Resources To An NE Assume a resource pooling setup with multiple FEs belonging to a resource pool all connected to a dormant resource pool CE. An NE system manager by demand could move an FE from the resource pool to a working NE by asking it first to connect to a CE on the working NE and then asking it to disconnect from the resource pool manager CE. 2.4. New LFB class installation A CE can learn, via the DynamicLFBLoading capability of the SM LFB, whether an FE is capable of loading new LFB classes. Provided that the FE supports new LFB class loading, the CE can request a new LFB to be installed and supported by the FE. To load an LFB class on an FE, the CE will have to provide the following parameters: Khasnabish, et al. Expires March 3, 2016 [Page 6] Internet-Draft ForCES LFB Subsidiary Management August 2015 LFB class - The LFB class ID LFB version - The version of the LFB class LFB class name - Optional, the LFB name Parameters - Optional parameters. These parameters are implementation specific, for example in one implementation they may contain the path where the LFB class implementation resides. The parameter are fields which will be need to be described in documentation, depending on the implementation. As an example the location of the LFB Class to be installed and/or mechanism to download it. The exact detail of the location semantics is implementation specific and out of scope of this document. However this LFB library provides a placeholder, namely the SupportedParameters capability, which will host any standardized parameters. This document does not standardize these parameters. It is expected that some future document will perform that task. These parameters are placeholders for future use, in order not to redefine the LFB class versions each time. They are simple strings that define the parameters supported by the LFB. The CE is expected to read this capability in order to understand the parameters it can use. 2.5. Logging Mechanism The SM LFB class also provides a useful log level manipulation. Experience has proven that the CE may require to increase or decrease the debug levels of parts of the FE, whether that be LFBs or portions of LFBs or generic processing code (all called modules). The module granularity is implementation specific and is not discussed in this document. The debug levels are derived from defined in [RFC3164]. 2.6. General Purpose Attribute Definition Experience has shown that a generic attribute name-value pair is useful for describing config information. This LFB class defines such a generic attribute name-value pair defined as a table of attribute-name values. The attribute name-value pair is implementation specific and at the moment there is nothing to standardize. As an example consider switches which have exactly the same LFB classes and capabilities but needing to be used in different roles. A good example would be a switch which could be used either as Spine or ToR in data-centre setups. An attribute which defines Khasnabish, et al. Expires March 3, 2016 [Page 7] Internet-Draft ForCES LFB Subsidiary Management August 2015 the role could be retrieved from the FE which will then dictate how it is controlled/configured. However, as in the case of LFB class loading parameters this LFB class library provides a placeholder, namely the SupportedArguments capability, which will host any standardized arguments. This document does not standardize these parameters. It is expected that some future document(s) help standardize or define good practise of such attributes. It is expected that the CE read this capability in order to know what the attributes it can use. 3. Applicability statement Examples of SM usage are the following, but not limiting, two usage scenarios. These two, but not limiting, scenarios are not implementation details, but rather depict how the SM class can be used to achieve the intended subsidiary mechanism for manipulating the configuration of FEs. 3.1. FE Integrated Only one instance of the SM LFB class can exist and is directly related to the FE. 3.2. Virtual FEs In the case of the FE software that has hierarchical virtual FEs, multiple instances of the SM LFB class can exist, one per each virtual FE. 4. SM Library 4.1. Frame Definitions This LFB class does not define any frames 4.2. Datatype Definitions This library defines the following datatypes. Khasnabish, et al. Expires March 3, 2016 [Page 8] Internet-Draft ForCES LFB Subsidiary Management August 2015 +------------+--------------------------------------+---------------+ | DataType | Type | Synopsis | | Name | | | +------------+--------------------------------------+---------------+ | loglevels | An enumerated char based atomic | The possible | | | datatype. | debug log | | | | levels. | | | | Derived from | | | | syslog. | | LogRowType | A struct containing three | The logging | | | components. The LogModule (string), | module row | | | the optional ModuleFilename (string) | | | | and optional DebugLevel which is one | | | | of the enumerated loglevels. | | | CERow | A Struct that contains three | A struct that | | | components. The address family of | defines the | | | the CE IP (uchar), the CE's IPs | CE table row. | | | (octetstring[16] and the CE's ID | | | | (uint32) | | | LCRowtype | A Struct that contains four | The LFB Class | | | components. The LFB Class ID | Config | | | (uint32), the LFB version | Definition | | | (string[8]), the optional LFB Name | | | | (string) and optional Parameters | | | | (string). | | | NameVal | A Struct that contains two | Arbitrary | | | components. An attribute name | Name Value | | | (string) and an attribute value | struct | | | (string) | | +------------+--------------------------------------+---------------+ FEM Data Types 4.3. Metadata Definitions This LFB does not define any metadata definition 4.4. SM The Subsidiary Mechanism LFB is an LFB that standardizes configuration of the FE parameters. 4.4.1. Data Handling The SM LFB does not handle any packets. It's function is to provide the configuration parameters to the CE to be updated at runtime. Khasnabish, et al. Expires March 3, 2016 [Page 9] Internet-Draft ForCES LFB Subsidiary Management August 2015 4.4.2. Components This LFB class has four components specified. The Debug component (ID 1) is a table to support changing of an FE's module debug levels. Changes in an FE's debug table rows will alter the debug level of the corresponding module. The LFBLoad component (ID 2) is a table of LFBs classes that the FE loads. Adding new rows in this table instructs the FE to load new LFB classes, and removing rows will unload them when possible. These two actions will in effect alter the SupportedLFBs capabilities table of FEObject LFB [RFC5812]. Each such row MUST provide (and is specified by this library) the LFB Class ID. Optionally the LFB class ID version may be specified, the FE MUST assume that version 1.0 is used when the version is unspecified. The AttributeValues component (ID 3) is the AttributeValues table, a generic attribute-value pair. The CEs (ID 4) is the table of runtime CEs we are asking the FE to be able to connect with. By adding a row in this table, the CE instructs the FE to be able to connect with the specified CE. By doing a delete on this table, the CE instructs the FE to terminate any connection with that CE. How the FE interacts with the new CEs is dependent on the operations discussed in [RFC7121] It is worth noting that the generic attribute value pairs, the LFBload parameters and the module information are all strings. To cope with string sizes, a CE application can extract that information from the component properties as defined in [RFC5812] 4.4.3. Capabilities This LFB provides three capabilities. The first, DynamicLFBLoading, specifies whether this FE supports dynamic loading of new LFB classes. The second, SupportedParameters, is a placeholder and will store all the supported parameters for LFB class loading. The final, SupportedAttributes, is also a placeholder and will store all the supported attributes for the attribute-value pair table. 4.4.4. Events This LFB has four events specified. Two events reflect CE additions and report to the CE whether an entry of the CEs information has been added or deleted. In both cases the event report constitutes the added or deleted row contents. Khasnabish, et al. Expires March 3, 2016 [Page 10] Internet-Draft ForCES LFB Subsidiary Management August 2015 The other two events reflect LFB class loading and notify whether an entry of the LFBLoad table is added or deleted. 5. XML for SM LFB loglevels The possible debug log levels. Derived from syslog. char DEB_OFF The logs are totally turned off DEB_EMERG Emergency level DEB_ALERT Alert level DEB_CRIT Critical level DEB_ERR error level DEB_WARNING warning level DEB_NOTICE Notice level DEB_INFO Info level Khasnabish, et al. Expires March 3, 2016 [Page 11] Internet-Draft ForCES LFB Subsidiary Management August 2015 DEB_DEBUG Debug level LogRowtype The logging module row lmodule The LOG Module Name string filename The Module File Name string deblvl debug level loglevels CERow The CE Table Row AddressFamily The address family uchar IFA_AF_INET IPv4 IFA_AF_INET6 IPv6 Khasnabish, et al. Expires March 3, 2016 [Page 12] Internet-Draft ForCES LFB Subsidiary Management August 2015 CEIP CE ip v4 or v6(selected by family) octetstring[16] CEID The CE ID uint32 LCRowtype The LFB Class Config Definition LFBClassID The LFB Class ID uint32 LFBVersion The LFB Class Version string LFBName The LFB Class Name string Parameters Optional parameters such as where the LFB is located string NameVal Khasnabish, et al. Expires March 3, 2016 [Page 13] Internet-Draft ForCES LFB Subsidiary Management August 2015 Arbitrary Name Value struct AttrName The Attribute Name string AttrVal The Attribute Value string SM The Subsidiary Management LFB 1.0 Debug A table to support changing of all debug levels LogRowtype LFBLoad An LFB Class to Load LCRowtype AttributeValues Table of general purpose SM attribute Values NameVal CEs Khasnabish, et al. Expires March 3, 2016 [Page 14] Internet-Draft ForCES LFB Subsidiary Management August 2015 Table of CEs we are asking the FE to associate with CERow DynamicLFBLoading This capability specifies whether this FE supports dynamic loading of new LFBs boolean SupportedParameters This capability contains all the supported parameters string SupportedAttributes This capability contains all the supported attributes names string CEAdded An CE has been added CEs CEs _CEIDsrowid_ Khasnabish, et al. Expires March 3, 2016 [Page 15] Internet-Draft ForCES LFB Subsidiary Management August 2015 CEDeleted An CE has been deleted CEs _CEIDsrowid_ CEs _CEIDsrowid_ LFBLoaded An LFB has been loaded LFBLoad LFBLoad _LFBLoadrowid_ LFBUnloaded An CE has been unloaded LFBLoad _LFBLoadrowid_ LFBLoad _LFBLoadrowid_ Khasnabish, et al. Expires March 3, 2016 [Page 16] Internet-Draft ForCES LFB Subsidiary Management August 2015 Figure 2: FEM XML LFB library 6. Security Considerations This document does not alter the ForCES Model [RFC5812] or the ForCES Protocol [RFC5810]. As such, it has no impact on their security considerations. This document simply defines the operational parameters and capabilities of an LFB that manages subsidiary mechanism for loading LFBs and create new connections between FEs and CEs. On the issue of trust, a designer should take into account that the CE that creating new connections to CEs is either: o The FE manager which is the one responsible for managing the FEs o An already associated CE In both these cases, the entity making the connections should already be trusted to perform such activities. If the entity making the connections is faulty, rogue or hacked, there is no way for the FE to know and will perform any action that the CE requests. Therefore, this document does not attempt to analyze the security issues that may arise from misuse of the SM LFB. Any such issues, if they exist, and mitigation strategies are for the designers of the particular SM implementation, not the general mechanism. The reader is also referred to the ForCES framework [RFC3746] document, particular section 8, for an analysis of potential threats introduced by ForCES and how the ForCES architecture addresses them. 7. IANA Considerations 7.1. LFB Class Names and LFB Class Identifiers LFB classes defined by this document belong to LFBs defined by Standards Track RFCs. According to IANA, the registration procedure is Standards Action for the range 0 to 65535 and First Come First Served with any publicly available specification for over 65535. This specification includes the following LFB class names and LFB class identifiers: Khasnabish, et al. Expires March 3, 2016 [Page 17] Internet-Draft ForCES LFB Subsidiary Management August 2015 +------------+-------+---------+------------------------+-----------+ | LFB Class | LFB | LFB | Description | Reference | | Identifier | Class | Version | | | | | Name | | | | +------------+-------+---------+------------------------+-----------+ | 19 | SM | 1.0 | An SM LFB to | This | | | | | standardize subsidiary | document | | | | | management for ForCES | | | | | | Network Elements | | +------------+-------+---------+------------------------+-----------+ Logical Functional Block (LFB) Class Names and Class Identifiers 8. Acknowledgments The authors would like to thank Damascene Joachimpillai, Joel Halpern, Chuanhuang Li, and many others for their discussions and support. The authors are grateful to Joel Halpern for shepherding this document. The authors would also like to thank Alia Atlas for taking on the role of sponsoring this document. Finally Juergen Schoenwaelder for his operational directorate's review and Alexey Melnikov for his security review. 9. References 9.1. Normative References [RFC5810] Doria, A., Ed., Hadi Salim, J., Ed., Haas, R., Ed., Khosravi, H., Ed., Wang, W., Ed., Dong, L., Gopal, R., and J. Halpern, "Forwarding and Control Element Separation (ForCES) Protocol Specification", RFC 5810, DOI 10.17487/RFC5810, March 2010, . [RFC5812] Halpern, J. and J. Hadi Salim, "Forwarding and Control Element Separation (ForCES) Forwarding Element Model", RFC 5812, DOI 10.17487/RFC5812, March 2010, . [RFC7121] Ogawa, K., Wang, W., Haleplidis, E., and J. Hadi Salim, "High Availability within a Forwarding and Control Element Separation (ForCES) Network Element", RFC 7121, DOI 10.17487/RFC7121, February 2014, . Khasnabish, et al. Expires March 3, 2016 [Page 18] Internet-Draft ForCES LFB Subsidiary Management August 2015 9.2. Informative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3164] Lonvick, C., "The BSD Syslog Protocol", RFC 3164, DOI 10.17487/RFC3164, August 2001, . [RFC3654] Khosravi, H., Ed. and T. Anderson, Ed., "Requirements for Separation of IP Control and Forwarding", RFC 3654, DOI 10.17487/RFC3654, November 2003, . [RFC3746] Yang, L., Dantu, R., Anderson, T., and R. Gopal, "Forwarding and Control Element Separation (ForCES) Framework", RFC 3746, DOI 10.17487/RFC3746, April 2004, . Authors' Addresses Bhumip Khasnabish ZTE TX, Inc. 55 Madison Avenue, Suite 160 Morristown, New Jersey 07960 USA Phone: +001-781-752-8003 Email: vumip1@gmail.com, bhumip.khasnabish@ztetx.com URI: http://tinyurl.com/bhumip/ Evangelos Haleplidis University of Patras Department of Electrical and Computer Engineering Patras 26500 Greece Email: ehalep@ece.upatras.gr Khasnabish, et al. Expires March 3, 2016 [Page 19] Internet-Draft ForCES LFB Subsidiary Management August 2015 Jamal Hadi Salim (editor) Mojatatu Networks Suite 200, 15 Fitzgerald Rd, Ottawa, Ontario K2H 9G1 Canada Email: hadi@mojatatu.com Khasnabish, et al. Expires March 3, 2016 [Page 20]