CCAMP C. Margaria, Ed. Internet-Draft Juniper Intended status: Standards Track G. Martinelli Expires: January 4, 2015 Cisco S. Balls B. Wright Metaswitch July 03, 2014 LSP Attribute in ERO draft-ietf-ccamp-lsp-attribute-ro-04 Abstract RFC5420 extends RSVP-TE to specify or record generic attributes which apply to the whole of the path of an LSP. This document proposes an extension to the RSVP ERO and RRO objects to allow it to specify or record generic attributes which apply to a given hop. 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 4, 2015. Copyright Notice Copyright (c) 2014 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 Margaria, et al. Expires January 4, 2015 [Page 1] Internet-Draft General ERO LSP parameters July 2014 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 1.1. Contributing Authors . . . . . . . . . . . . . . . . . . 3 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Specifying Hop Attribute . . . . . . . . . . . . . . . . . . 3 3.1. ERO_HOP_ATTRIBUTE subobject . . . . . . . . . . . . . . . 3 3.2. HOP Attributes TLVs . . . . . . . . . . . . . . . . . . . 4 3.3. Procedures . . . . . . . . . . . . . . . . . . . . . . . 5 4. Recording Hop attribute . . . . . . . . . . . . . . . . . . . 6 4.1. RRO_HOP_ATTRIBUTE subobject . . . . . . . . . . . . . . . 6 4.2. Procedures . . . . . . . . . . . . . . . . . . . . . . . 7 4.2.1. Subobject presence rule . . . . . . . . . . . . . . . 7 4.2.2. Reporting Compliance with ERO Hop Attributes . . . . 7 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 5.1. ERO LSP Attribute Subobject . . . . . . . . . . . . . . . 7 5.2. RRO LSP Attribute Subobject . . . . . . . . . . . . . . . 7 5.3. Existing LSP Attribute TLVs . . . . . . . . . . . . . . . 7 5.3.1. Attribute Flags . . . . . . . . . . . . . . . . . . . 8 5.3.2. Service ID TLV . . . . . . . . . . . . . . . . . . . 8 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 8.1. Normative References . . . . . . . . . . . . . . . . . . 9 8.2. Informative References . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 1. Introduction Generalized MPLS (GMPLS) Traffic Engineering (TE) Label Switched Paths (LSPs) can be route-constrained by making use of the Explicit Route (ERO) object and related sub-objects as defined in [RFC3209], [RFC3473], [RFC3477], [RFC4873], [RFC4874], [RFC5520] and [RFC5553]. Several documents have identified the need for attributes that can be targeted at specific hops in the path of an LSP, including [RFC6163], [I-D.ietf-ccamp-wson-signaling], [I-D.dong-ccamp-rsvp-te-mpls-tp-li-lb] or [I-D.ali-ccamp-rc-objective-function-metric-bound],. This document provides a generic mechanism for use by these other documents. RSVP already supports generic extension of LSP attributes in [RFC5420]. In order to support current and future ERO constraint Margaria, et al. Expires January 4, 2015 [Page 2] Internet-Draft General ERO LSP parameters July 2014 extensions this document defines a mechanism to define per-Hop attributes. 1.1. Contributing Authors 1.2. 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 RFC 2119 [RFC2119]. 2. Requirements The requirement is to provide a generic mechanism to carry information related to specific nodes when signaling an LSP. This document does not restrict what that information can be used for. A mechanism similar to LSP attribute defined [RFC5420] should be expressed in ERO and SERO objects. A new ERO sub-object is defined, containing a list of generic per-Hop attributes. The mechanism defined in this document limits itself to single HOP attributes, and does not address attributes valid for a LSP section [[CREF1: This can be revised based on feedback --Ed.]] 3. Specifying Hop Attribute The ERO Attributes subobject may be carried in the ERO or SERO object if they are present. The subobject uses the standard format of an ERO subobject. 3.1. ERO_HOP_ATTRIBUTE subobject The length is variable and content is a list of HOP Attributes TLVs defined in Section 3.2. The size of the ERO sub-object limits the size of the attribute TLV to 250 bytes. The typical size of currently defined and forthcoming LSP_ATTRIBUTE TLVs applicable to a specific hop (WSON_SIGNALING, OF and Metric) is not foreseen to exceed this limit. The ERO_HOP_ATTRIBUTE subobject is defined as follows: Margaria, et al. Expires January 4, 2015 [Page 3] Internet-Draft General ERO LSP parameters July 2014 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |L| Type | Length | Reserved |R| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // Attributes TLVs // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ See [RFC3209] for a description of L parameters. The attributes TLV are encoded as defined in section Section 3.2. Type x TBD by IANA. Length The Length contains the total length of the subobject in bytes, including the Type and Length fields. The Length MUST be always divisible by 4. Reserved Reserved, must be set to 0 when the subobject is inserted in the ERO, MUST NOT be changed when a node process the ERO and must be ignored on the node addressed by the preceding ERO subobjects. R This bit reflects the LSP_REQUIRED_ATTRIBUTE and LSP_ATTRIBUTE semantic defined in [RFC5420]. When set it indicates required hop attributes to be processed by the node. When cleared, it indicates that the hop attributes are not required as described in Section Section 3.3. Attributes TLVs as defined in Section 3.2 . 3.2. HOP Attributes TLVs ERO Attributes carried by the new objects defined in this document are encoded within TLVs. One or more TLVs may be present in each object. There are no ordering rules for TLVs, and no interpretation should be placed on the order in which TLVs are received. Each TLV is encoded as follows. Margaria, et al. Expires January 4, 2015 [Page 4] Internet-Draft General ERO LSP parameters July 2014 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // Value // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type The identifier of the TLV.. Length Indicates the total length of the TLV in octets. That is, the combined length of the Type, Length, and Value fields, i.e., four plus the length of the Value field in octets. The entire TLV MUST be padded with between zero and three trailing zeros to make it four-octet aligned. The Length field does not count any padding. Value The data carried in the TLV. 3.3. Procedures As described in [RFC3209] and [RFC3473] the ERO is managed as a list where each hop information starts with a subobject identifying an abstract node or link. The ERO_HOP_ATTRIBUTE subobject must be appended after the existing subobjects defined in [RFC3209], [RFC3473], [RFC3477], [RFC4873], [RFC4874], [RFC5520] and [RFC5553]. Several ERO_HOP_ATTRIBUTE subobject MAY be present, for each hop. If a node is processing an ERO_HOP_ATTRIBUTE subobject and does not support handling of the subobject it will behave as described in [RFC3209] when an unrecognized ERO subobject is encountered. This node will return a PathErr with error code "Routing Error" and error value "Bad EXPLICIT_ROUTE object" with the EXPLICIT_ROUTE object included, truncated (on the left) to the offending unrecognized subobject. When the R bit is set a node MUST examine the attribute TLV present in the subobject following the rules described in [RFC5420] section 5.2. When the R bit is not set a node MUST examine the attribute TLV present in the subobject following the rules described in [RFC5420] section 4.2. A node processing an ERO_HOP_ATTRIBUTE subobject with an HOP attribute TLV longer than the ERO subobject SHOULD return a PathErr with error code "Routing Error" and error value "Bad EXPLICIT_ROUTE Margaria, et al. Expires January 4, 2015 [Page 5] Internet-Draft General ERO LSP parameters July 2014 object" with the EXPLICIT_ROUTE object included, truncated (on the left) to the offending malformed subobject. The processing of the Hop attribute TLVs should be described in the documents defining them. 4. Recording Hop attribute In some cases it is important to determine if an optional Hop attribute has been processed by a node. 4.1. RRO_HOP_ATTRIBUTE subobject The RRO_HOP_ATTRIBUTE subobject may be carried in the RECORD_ROUTE object if it is present. The subobject uses the standard format of an RRO subobject. The RRO_HOP_ATTRIBUTE subobject is defined as follows: 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |L| Type | Length | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // Attributes TLVs // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ See [RFC3209] for a description of L parameters. The attributes TLV are encoded as defined in section Section 3.2. Type x TBD by IANA. Length The Length contains the total length of the subobject in bytes, including the Type and Length fields. The Length MUST be always divisible by 4. Reserved Reserved, must be set to 0 when the subobject is inserted in the RRO, MUST NOT be changed when a node process the RRO and must be ignored on the node addressed by the preceding RRO subobjects. Attributes TLVs The processed or addition HOP attributes, using the format defined in Section 3.2 . Margaria, et al. Expires January 4, 2015 [Page 6] Internet-Draft General ERO LSP parameters July 2014 4.2. Procedures 4.2.1. Subobject presence rule The RRO rules defined in [RFC3209] are not changed. The RRO_HOP_ATTRIBUTE subobject must be pushed after the RRO attribute subobject (if present) defined in in [RFC5420]. The RRO_HOP_ATTRIBUTE subobject MAY be present between a pair of subobject identifying LSR or links. All such subobjects MUST be forwarded unmodified by transit LSRs. 4.2.2. Reporting Compliance with ERO Hop Attributes To report that an ERO Hop attribute has been considered, or to report an additional attribute, an LSR MAY add a RRO_HOP_ATTRIBUTE subobject with the HOP Attribute TLV which describes the attribute to be reported. The requirement to report compliance MUST be specified in the document that defines the usage of an Hop attribute. [[CREF2: This is not the most efficient encoding, a more efficient encoding would use a bit field ala RFC5420 --Ed.]] 5. IANA Considerations 5.1. ERO LSP Attribute Subobject IANA is requested to make the following subobject allocations from the "EXPLICIT_ROUTE Subobject Type" registry. Sub-object type TBA Name ERO HOP Attribute Reference This document 5.2. RRO LSP Attribute Subobject IANA is requested to make the following subobject allocations from the "RECORD_ROUTE Subobject Type" registry. Sub-object type TBA Name RRO HOP Attribute Reference This document 5.3. Existing LSP Attribute TLVs IANA is request to add the following information for each TLV in the RSVP TLV type identifier registry. o Whether allowed on LSP attribute ERO subobject Margaria, et al. Expires January 4, 2015 [Page 7] Internet-Draft General ERO LSP parameters July 2014 The existing registry is modified for existing TLVs. 5.3.1. Attribute Flags The new TLV type definition is as follow o TLV Type = 1 o TLV Name = Attribute Flags TLV o Allowed on LSP_ATTRIBUTES object o Allowed on LSP_REQUIRED_ATTRIBUTES object o Allowed on LSP attribute ERO subobject 5.3.2. Service ID TLV The new TLV type definition is as follow o TLV Type = 2 o TLV Name = Attribute Flags TLV o Allowed on LSP_ATTRIBUTES object o Not allowed on LSP_REQUIRED_ATTRIBUTES object o ? on LSP attribute ERO subobject 6. Security Considerations None. 7. Acknowledgments The authors would like to thanks Lou Berger for his directions and Attila Takacs for inspiring this [I-D.kern-ccamp-rsvpte-hop-attributes]. The authors also thanks Dirk Schroetter for his contribution to the initial versions of the documents (version -00 up to -02). 8. References Margaria, et al. Expires January 4, 2015 [Page 8] Internet-Draft General ERO LSP parameters July 2014 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, December 2001. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links in Resource ReSerVation Protocol - Traffic Engineering (RSVP-TE)", RFC 3477, January 2003. [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel, "GMPLS Segment Recovery", RFC 4873, May 2007. [RFC4874] Lee, CY., Farrel, A., and S. De Cnodder, "Exclude Routes - Extension to Resource ReserVation Protocol-Traffic Engineering (RSVP-TE)", RFC 4874, April 2007. [RFC5420] Farrel, A., Papadimitriou, D., Vasseur, JP., and A. Ayyangarps, "Encoding of Attributes for MPLS LSP Establishment Using Resource Reservation Protocol Traffic Engineering (RSVP-TE)", RFC 5420, February 2009. [RFC5520] Bradford, R., Vasseur, JP., and A. Farrel, "Preserving Topology Confidentiality in Inter-Domain Path Computation Using a Path-Key-Based Mechanism", RFC 5520, April 2009. [RFC5553] Farrel, A., Bradford, R., and JP. Vasseur, "Resource Reservation Protocol (RSVP) Extensions for Path Key Support", RFC 5553, May 2009. 8.2. Informative References [I-D.ali-ccamp-rc-objective-function-metric-bound] Ali, Z., Swallow, G., Filsfils, C., Fang, L., Kumaki, K., Kunze, R., Ceccarelli, D., and X. Zhang, "Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extension for Signaling Objective Function and Metric Bound", draft-ali-ccamp-rc-objective-function-metric- bound-05 (work in progress), February 2014. Margaria, et al. Expires January 4, 2015 [Page 9] Internet-Draft General ERO LSP parameters July 2014 [I-D.dong-ccamp-rsvp-te-mpls-tp-li-lb] Dong, J., Chen, M., and Z. Li, "GMPLS RSVP-TE Extensions for Lock Instruct and Loopback", draft-dong-ccamp-rsvp-te- mpls-tp-li-lb-05 (work in progress), December 2012. [I-D.ietf-ccamp-wson-signaling] Bernstein, G., Xu, S., Lee, Y., Martinelli, G., and H. Harai, "Signaling Extensions for Wavelength Switched Optical Networks", draft-ietf-ccamp-wson-signaling-07 (work in progress), March 2014. [I-D.kern-ccamp-rsvpte-hop-attributes] Kern, A. and A. Takacs, "Encoding of Attributes of LSP intermediate hops using RSVP-TE", draft-kern-ccamp-rsvpte- hop-attributes-00 (work in progress), October 2009. [RFC6163] Lee, Y., Bernstein, G., and W. Imajuku, "Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)", RFC 6163, April 2011. Authors' Addresses Cyril Margaria (editor) Juniper 200 Somerset Corporate Boulevard, , Suite 4001 Bridgewater, NJ 08807 USA Email: cmargaria@juniper.net Giovanni Martinelli Cisco via Philips 12 Monza 20900 IT Phone: +39 039 209 2044 Email: giomarti@cisco.com Margaria, et al. Expires January 4, 2015 [Page 10] Internet-Draft General ERO LSP parameters July 2014 Steve Balls Metaswitch 100 Church Street Enfield EN2 6BQ UJ Phone: +44 208 366 1177 Email: steve.balls@metaswitch.com Ben Wright Metaswitch 100 Church Street Enfield EN2 6BQ UJ Phone: +44 208 366 1177 Email: Ben.Wright@metaswitch.com Margaria, et al. Expires January 4, 2015 [Page 11]