CCAMP                                                   C. Margaria, Ed.
Internet-Draft                                                   Juniper
Intended status: Standards Track                           G. Martinelli
Expires: January 4, April 26, 2015                                            Cisco
                                                                S. Balls
                                                               B. Wright
                                                              Metaswitch
                                                           July 03,
                                                        October 23, 2014

                          LSP Attribute in ERO
                  draft-ietf-ccamp-lsp-attribute-ro-04
                  draft-ietf-ccamp-lsp-attribute-ro-05

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

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   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on January 4, April 26, 2015.

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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
   4.  Recording Hop attribute . . . . . . . . . . . . . . . . . . .   6   5
     4.1.  RRO_HOP_ATTRIBUTE subobject . . . . . . . . . . . . . . .   6   5
     4.2.  Procedures  . . . . . . . . . . . . . . . . . . . . . . .   7   6
       4.2.1.  Subobject presence rule . . . . . . . . . . . . . . .   7   6
       4.2.2.  Reporting Compliance with ERO Hop Attributes  . . . .   7   6
       4.2.3.  Compatibility with RRO Attributes subobject . . . . .   6
   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
       5.3.3.  OAM Configuration TLV . . . . . . . . . . . . . . . .   8
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   8   9
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   8   9
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8   9
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   9
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   9  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10  11

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
   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:

      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

   The L, Type and Length parameters are as defined in [RFC3209] section
   4.3.3.  The Type for a description of L parameters. the ERO_HOP_ATTRIBUTE subobject is TBA by IANA.
   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 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
      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 MAY be present in each
   object.  There are no ordering rules for TLVs, and no interpretation
   should
   SHOULD NOT be placed on the order in which TLVs are received.

   Each TLV is encoded 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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             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 format is defined in the TLV. [RFC5420] section 3.

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 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
   object" with the EXPLICIT_ROUTE object included, truncated (on the
   left) to the offending malformed subobject.  The processing of the
   Hop attribute TLVs should 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

   The Type and Length parameters are as defined in [RFC3209] section
   4.4.1.  The Type for a description of L parameters. the RRO_HOP_ATTRIBUTE subobject is TBA by IANA.
   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 .

4.2.  Procedures

4.2.1.  Subobject presence rule

   The RRO rules defined in [RFC3209] are not changed.  The
   RRO_HOP_ATTRIBUTE subobject must 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

4.2.3.  Compatibility with RRO Attributes subobject

   The RRO_HOP_ATTRIBUTE extends the capability of the RRO Attributes
   subobject defined in [RFC5420] section 7.2 by allowing the node to
   report the attribute value.  The mechanism defined in this document
   is compatible with the RRO Attributes using the following procedures.

   For LSP attributes signaled in the LSP_ATTRIBUTES or
   LSP_REQUIRED_ATTRIBUTES, a node SHOULD use the RRO Attributes to
   report processing of those attributes.  If a node desires to include
   the LSP_ATTRIBUTE TLV, it SHOULD use both the RRO Attributes and
   RRO_HOP_ATTRIBUTE.  Head end nodes not supporting the
   RRO_HOP_ATTRIBUTE will drop the information.

   For LSP attributes signaled in the ERO Hop attribute and not in the
   LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES, if a bit field ala RFC5420 --Ed.]] node desires to
   include the LSP_ATTRIBUTE, it SHOULD use the RRO_HOP_ATTRIBUTE and
   SHOULD NOT use the RRO Attributes.

5.  IANA Considerations

5.1.  ERO LSP Attribute Subobject

   IANA is requested manages the "RSVP PARAMETERS" registry located at
   http://www.iana.org/assignments/rsvp-parameters/rsvp-parameters.xml.
   We request IANA to make an allocation in the following subobject allocations from
   the "EXPLICIT_ROUTE Subobject Type" registry. Sub-object type 20
   EXPLICIT_ROUTE - Type 1 Explicit Route registry.

   This document introduces a new ERO sub-object:

                  Value  Description       Reference
                  ------ ----------------- --------------
                  TBA
                     Name    ERO HOP Attribute
                     Reference This document

5.2.  RRO LSP Attribute Subobject

   IANA is requested manages the "RSVP PARAMETERS" registry located at
   http://www.iana.org/assignments/rsvp-parameters/rsvp-parameters.xml.
   We request IANA to make an allocation in the following subobject allocations from
   the "RECORD_ROUTE Subobject Type" registry. Sub-object type 21
   ROUTE_RECORD - Type 1 Route Record registry.

   This document introduces a new RRO sub-object:

                  Value  Description       Reference
                  ------ ----------------- --------------
                  TBA
                     Name    RRO HOP Attribute
                     Reference This document

5.3.  Existing LSP Attribute TLVs

   IANA is manages the "RSVP-TE PARAMETERS" registry located at
   http://www.iana.org/assignments/rsvp-te-parameters/rsvp-te-
   parameters.xml.  The "Attributes TLV Space" registry manage the
   following attributes, as defined in [RFC5420]:

   o  TLV Type (T-field value)

   o  TLV Name

   o  Whether allowed on LSP_ATTRIBUTES object

   o  Whether allowed on LSP_REQUIRED_ATTRIBUTES object

   We request IANA to add the following information for each TLV in the
   RSVP TLV type identifier registry.

   o  Whether allowed on LSP attribute ERO subobject

   The existing registry is modified for existing TLVs. TLVs as follows:

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

   o  Defining RFC = [RFC5420]

5.3.2.  Service ID TLV

   The new TLV type definition is as follow

   o  TLV Type = 2

   o  TLV Name = Attribute Flags Service ID TLV

   o  Allowed on LSP_ATTRIBUTES object

   o  Not allowed on LSP_REQUIRED_ATTRIBUTES object

   o  ?  Not allowed on LSP attribute ERO subobject

   o  Defining RFC = [RFC7260]

5.3.3.  OAM Configuration TLV

   The new TLV type definition is as follow

   o  TLV Type = 3

   o  TLV Name = OAM Configuration TLV

   o  Allowed on LSP_ATTRIBUTES object

   o  Allowed on LSP_REQUIRED_ATTRIBUTES object
   o  Not allowed on LSP attribute ERO subobject

   o  Defining RFC = [RFC6060]

6.  Security Considerations

   None.

   This document adds new subobject in the EXPLICIT_ROUTE and the
   ROUTE_RECORD object carried in RSVP message used in MPLS and GMPLS
   signaling.  It builds on mechanism defined in [RFC3209] and [RFC5420]
   and does not introduce any new security.  The existing security
   considerations described in [RFC2205], [RFC3209], [RFC3473] and
   [RFC5420] do apply.

   As any RSVP-TE signaling request, the procedures defined in this
   document permit the transfer and reporting of functional preferences
   on specific node.  This may reveal information about the LSP request
   and status to anyone with unauthorized access.  The mechanism
   described in this document do not contribute to this issue, which can
   be only resolved by encrypting the content of the whole signaling
   message.

   In addition the reporting of attributes using the RRO may reveal
   details about the node that the operator wishes to remains
   confidential.  The same strategy and policies that apply to other RRO
   subobjects also apply to this new mechanism.  It is recommended that
   domain boundary policies take the releasing of RRO hop attributes
   into consideration.

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

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2205]  Braden, B., Zhang, L., Berson, S., Herzog, S., and S.
              Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
              Functional Specification", RFC 2205, September 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.

   [RFC6060]  Fedyk, D., Shah, H., Bitar, N., and A. Takacs,
              "Generalized Multiprotocol Label Switching (GMPLS) Control
              of Ethernet Provider Backbone Traffic Engineering (PBB-
              TE)", RFC 6060, March 2011.

   [RFC7260]  Takacs, A., Fedyk, D., and J. He, "GMPLS RSVP-TE
              Extensions for Operations, Administration, and Maintenance
              (OAM) Configuration", RFC 7260, June 2014.

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.

   [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 draft-ietf-ccamp-wson-signaling-09
              (work in progress), March September 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
   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