Network Work group N. Kumar Internet-Draft C. Pignataro Intended status: Standards Track P. Quinn Expires: September 14, 2017 Cisco Systems, Inc. March 13, 2017 IPFIX Information Element extension for SFC draft-kumar-ipfix-sfc-extension-05 Abstract Service Function Chaining (SFC) is an architecture that enables any operator to apply selective set of services by steering the traffic through an ordered set of service functions without any topology dependency. This document defines the required Information Elements to represent the details about service flows over any Service Function Path. 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 September 14, 2017. Copyright Notice Copyright (c) 2017 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 Kumar, et al. Expires September 14, 2017 [Page 1] Internet-Draft March 2017 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 . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements notation . . . . . . . . . . . . . . . . . . . . 3 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Network Service Header . . . . . . . . . . . . . . . . . . . 3 5. Flow measurement in SFC environment . . . . . . . . . . . . . 4 5.1. Observation Point . . . . . . . . . . . . . . . . . . . . 5 5.2. Flow measurement . . . . . . . . . . . . . . . . . . . . 5 6. Service Flow Information Elements . . . . . . . . . . . . . . 6 6.1. nshBaseVersion . . . . . . . . . . . . . . . . . . . . . 6 6.2. nshBaseFlags . . . . . . . . . . . . . . . . . . . . . . 6 6.3. nshBaseHeaderLength . . . . . . . . . . . . . . . . . . . 7 6.4. nshBaseMDType . . . . . . . . . . . . . . . . . . . . . . 7 6.5. nshBaseNextProtocol . . . . . . . . . . . . . . . . . . . 7 6.6. nshSphServicePathID . . . . . . . . . . . . . . . . . . . 8 6.7. nshSphServiceIndex . . . . . . . . . . . . . . . . . . . 8 6.8. nshMetadataMch . . . . . . . . . . . . . . . . . . . . . 9 6.9. nshMetadataVch . . . . . . . . . . . . . . . . . . . . . 9 6.10. nshIPv4NextSFF . . . . . . . . . . . . . . . . . . . . . 9 6.11. nshIPv6NextSFF . . . . . . . . . . . . . . . . . . . . . 10 6.12. nshEtherNextSFF . . . . . . . . . . . . . . . . . . . . . 10 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 8. Security Considerations . . . . . . . . . . . . . . . . . . . 11 9. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 11 10. Contributing Authors . . . . . . . . . . . . . . . . . . . . 11 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 11.1. Normative References . . . . . . . . . . . . . . . . . . 11 11.2. Informative References . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 1. Introduction [RFC7665] introduces and explains SFC architecture that enables any operator to apply selective set of services by steering the traffic through an ordered set of service functions without any topology dependency. Such ordered set of service functions to be applied to a packet is defined as service function chaining. As defined in [I-D.ietf-sfc-nsh], a classifier will add Network Service Header (NSH) to a packet that defines the corresponding service path to follow. Kumar, et al. Expires September 14, 2017 [Page 2] Internet-Draft March 2017 This document defines the required Information Elements to represent the details about traffic flows over any Service Function Path and export to Collector. 2. Requirements notation 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]. 3. Terminology This document uses the terminologies defined in [RFC7665] and [RFC7011]. In addition, this document defines the below terminologies: Service Flow A Service Flow is defined as a set of packets over a specific Service Function Path. 4. Network Service Header Section 3.1 of [I-D.ietf-sfc-nsh] defines the Network Service Header format used by the classifier to encapsulate the traffic, carrying instruction about the service functions to be applied to the packet. This header comprises a 4 byte base header followed by a 4 byte service path header and a variable size context header. In order to accomodate different needs from different use cases, there are 2 types of Network Service Header defined in [I-D.ietf-sfc-nsh] that preserves same Base header and Service Path header while differs in Context header. NSH MD-type 1 have a fixed size Mandatory Context header while NSH MD-type 2 have a variable size TLV based context header. The details are below: Kumar, et al. Expires September 14, 2017 [Page 3] Internet-Draft March 2017 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Ver|O|C|R|R|R|R|R|R| Length | MD-type=0x1 | Next Protocol | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Service Path ID | Service Index | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Mandatory Context Header | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Mandatory Context Header | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Mandatory Context Header | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Mandatory Context Header | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: NSH MD-type 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Ver|O|C|R|R|R|R|R|R| Length | MD-type=0x2 | Next Protocol | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Service Path ID | Service Index | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Optional Variable Length Context Headers ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: NSH MD-type 2 The details about different header fields are detailed in Section 3.4 and 3.5 of [I-D.ietf-sfc-nsh]. 5. Flow measurement in SFC environment SFC introduces the concept of steering user traffic over an ordered set of service function by utilizing service overlay between service functions over the existing network topology. The measurement of Service flow over Service Function Chain are required for various application such as but not limited to below: o Capacity Planning - To ensure distributing load between Service Functions. Kumar, et al. Expires September 14, 2017 [Page 4] Internet-Draft March 2017 o OAM and troubleshooting - To measure the performance and troubleshooting failures. o Traffic Profiling - Determine the characteristics of traffic flow over SFP. o Security - To identify DoS attack or malicious intrusion. In SFC environment, Classifier and Service Function Forwarder (SFF) are the different nodes that handles SFC encapsulation and it is appropriate to collect the Service Flow records in these nodes. 5.1. Observation Point An Observation point in SFC environment is where Flow record for Service Flow will be collected and exported to the Collector. In a Classifier or SFF, an Observation point can be any physical or logical port that: o Forwards NSH encapsulated packets or frame from Classifier to SFF. o Receives NSH encapsulated packets or frame from Classifier or previous SFF. o Receives NSH encapsulated packets or frame from Service Function after packet treatment applied. o Forwards NSH encapsulated packets or frame to next Service Function Forwarder. o Forwards NSH encapsulated packets or frame to Service Function for packet treatment. 5.2. Flow measurement The ability to collect Flow record for different flows observed at the above range of Observation point allows an Operator to measure flow properties before and after the application of any service function within a service function path. An implementation SHOULD support the use of Information Elements defined in section 6 to measure and export the flow information. In addition, it also MAY support the use of other Flow keys relevant to the underlay network to collect any additional information from transport header encapsulating NSH header. Kumar, et al. Expires September 14, 2017 [Page 5] Internet-Draft March 2017 6. Service Flow Information Elements This document defines the below set of Information Elements that are necessary for enabling IPFIX traffic measurement for Service Flow: +---------+------------------------------------------+ | ID | Name | +---------+------------------------------------------+ | TBD1 | nshBaseVersion | | TBD2 | nshBaseFlags | | TBD3 | nshBaseHeaderLength | | TBD4 | nshBaseMDType | | TBD5 | nshBaseNextProtocol | | TBD6 | nshSphServicePathID | | TBD7 | nshSphServiceIndex | | TBD8 | nshMetadataMch | | TBD9 | nshMetadataVch | | TBD10 | nshIPv4NextSFF | | TBD11 | nshIPv6NextSFF | | TBD12 | nshEtherNextSFF | +---------+------------------------------------------+ 6.1. nshBaseVersion Description: The Version field in NSH header. Abstract Data Type: unsigned8 Element ID: TBD1 Data Type Semantic: identifier Range: The valid range is 0-3. Reference: See Section 3.2 of [I-D.ietf-sfc-nsh] 6.2. nshBaseFlags Description: The flag bits from bit position 2 to 9 in NSH Base header. This information is encoded as a bit field. Kumar, et al. Expires September 14, 2017 [Page 6] Internet-Draft March 2017 Abstract Data Type: unsigned8 Element ID: TBD2 Data Type Semantic: flags Reference: See Section 3.2 of [I-D.ietf-sfc-nsh] 6.3. nshBaseHeaderLength Description: The length of the NSH header including any optional variable TLVs. Abstract Data Type: unsigned8 Element ID: TBD3 Range: The valid range is 0-255. Reference: See Section 3.2 of [I-D.ietf-sfc-nsh] 6.4. nshBaseMDType Description: Defines the Metadata format beyond the NSH Base header. Abstract Data Type: unsigned8 Element ID: TBD4 Data Type Semantic: identifier Reference: See Section 3.2 of [I-D.ietf-sfc-nsh] 6.5. nshBaseNextProtocol Description: This indicates the type of the payload packet encapsulated within the NSH header. Kumar, et al. Expires September 14, 2017 [Page 7] Internet-Draft March 2017 Abstract Data Type: unsigned8 Element ID: TBD5 Data Type Semantic: identifier Reference: See Section 3.2 of [I-D.ietf-sfc-nsh] 6.6. nshSphServicePathID Description: Service Path ID uniquely identifies the Service Chain which is a sequence of service function to be applied on the payload packet. Abstract Data Type: unsigned32 Element ID: TBD6 Data Type Semantic: identifier Reference: See Section 3.3 of [I-D.ietf-sfc-nsh] 6.7. nshSphServiceIndex Description: Service Index identifies the next service function to be applied in the service chain. Abstract Data Type: unsigned8 Element ID: TBD7 Range : The valid range is between 0-255. Reference: See Section 3.3 of [I-D.ietf-sfc-nsh] Kumar, et al. Expires September 14, 2017 [Page 8] Internet-Draft March 2017 6.8. nshMetadataMch Description: When MD Type is 1 on NSH header, Service Base header is followed by fixed size Mandatory Context Header. The format of this header varies depending on the implementation. This information element is of 16 bytes size. Abstract Data Type: OctetArray Element ID: TBD8 Reference: See Section 3.4 of [I-D.ietf-sfc-nsh] 6.9. nshMetadataVch Description: When MD Type is 2 on NSH header, Service Base header is followed by Variable size Context Header. The format of this header varies depending on the implementation. This Informational element carries n octets from the NSH Service Path header. A value of 64 reduced from nshBaseHeaderLength expresses how much Metadata was observed, while the remainder is padding. Abstract Data Type: OctetArray Element ID: TBD9 Reference: See Section 3.5 of [I-D.ietf-sfc-nsh] 6.10. nshIPv4NextSFF Description: This defines the IPv4 address of the next SFF in the Service Function Path. This Information element is of size 4 bytes. Abstract Data Type: ipv4Address Element ID: TBD10 Kumar, et al. Expires September 14, 2017 [Page 9] Internet-Draft March 2017 Data Type Semantic: identifier Reference: See Section 7.1 of [I-D.ietf-sfc-nsh] 6.11. nshIPv6NextSFF Description: This defines the IPv6 address of the next SFF in the Service Function Path. This Information element is of size 16 bytes. Abstract Data Type: ipv6Address Element ID: TBD11 Data Type Semantic: identifier Reference: See Section 7.1 of [I-D.ietf-sfc-nsh] 6.12. nshEtherNextSFF Description: This defines the Ethernet Address of the next SFF in the Service Function Path. This Information element is of size 16 bytes. Abstract Data Type: macAddress Element ID: TBD12 Data Type Semantic: identifier Reference: See Section 7.1 of [I-D.ietf-sfc-nsh] 7. IANA Considerations To be Updated. Kumar, et al. Expires September 14, 2017 [Page 10] Internet-Draft March 2017 8. Security Considerations TBD 9. Acknowledgement The authors would like to thank Jim Guichard, Stewart Bryant, Benoit Claise, Richard Furr and Joel M. Harpern for their contribution. 10. Contributing Authors TBD 11. References 11.1. Normative References [I-D.ietf-sfc-nsh] Quinn, P. and U. Elzur, "Network Service Header", draft- ietf-sfc-nsh-12 (work in progress), February 2017. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken, "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of Flow Information", STD 77, RFC 7011, DOI 10.17487/RFC7011, September 2013, . 11.2. Informative References [RFC7012] Claise, B., Ed. and B. Trammell, Ed., "Information Model for IP Flow Information Export (IPFIX)", RFC 7012, DOI 10.17487/RFC7012, September 2013, . [RFC7013] Trammell, B. and B. Claise, "Guidelines for Authors and Reviewers of IP Flow Information Export (IPFIX) Information Elements", BCP 184, RFC 7013, DOI 10.17487/RFC7013, September 2013, . Kumar, et al. Expires September 14, 2017 [Page 11] Internet-Draft March 2017 [RFC7665] Halpern, J., Ed. and C. Pignataro, Ed., "Service Function Chaining (SFC) Architecture", RFC 7665, DOI 10.17487/RFC7665, October 2015, . Authors' Addresses Nagendra Kumar Cisco Systems, Inc. 7200 Kit Creek Road Research Triangle Park, NC 27709 US Email: naikumar@cisco.com Carlos Pignataro Cisco Systems, Inc. 7200 Kit Creek Road Research Triangle Park, NC 27709-4987 US Email: cpignata@cisco.com Paul Quinn Cisco Systems, Inc. 170 West Tasman Dr San Jose, CA US Email: paulq@cisco.com Kumar, et al. Expires September 14, 2017 [Page 12]