draft-ietf-ospf-segment-routing-msd-10.txt   draft-ietf-ospf-segment-routing-msd-11.txt 
OSPF Working Group J. Tantsura OSPF Working Group J. Tantsura
Internet-Draft Nuage Networks Internet-Draft Nuage Networks
Intended status: Standards Track U. Chunduri Intended status: Standards Track U. Chunduri
Expires: October 7, 2018 Huawei Technologies Expires: November 8, 2018 Huawei Technologies
S. Aldrin S. Aldrin
Google, Inc Google, Inc
P. Psenak P. Psenak
Cisco Systems Cisco Systems
April 05, 2018 May 07, 2018
Signaling MSD (Maximum SID Depth) using OSPF Signaling MSD (Maximum SID Depth) using OSPF
draft-ietf-ospf-segment-routing-msd-10 draft-ietf-ospf-segment-routing-msd-11
Abstract Abstract
This document defines a way for an OSPF Router to advertise multiple This document defines a way for an OSPF Router to advertise multiple
types of supported Maximum SID Depths (MSDs) at node and/or link types of supported Maximum SID Depths (MSDs) at node and/or link
granularity. Such advertisements allow entities (e.g., centralized granularity. Such advertisements allow entities (e.g., centralized
controllers) to determine whether a particular SID stack can be controllers) to determine whether a particular SID stack can be
supported in a given network. This document only defines one type of supported in a given network. This document defines only one type of
MSD maximum label imposition, but defines an encoding which can MSD, but defines an encoding that can support other MSD types. Here
support other MSD types. Here the term OSPF means both OSPFv2 and the term OSPF means both OSPFv2 and OSPFv3.
OSPFv3.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on October 7, 2018. This Internet-Draft will expire on November 8, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions used in this document . . . . . . . . . . . . 3 1.1. Conventions used in this document . . . . . . . . . . . . 3
1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3 1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Node MSD Advertisement . . . . . . . . . . . . . . . . . . . 4
3. Node MSD TLV . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Link MSD sub-TLV . . . . . . . . . . . . . . . . . . . . . . 5
4. Link MSD sub-TLV . . . . . . . . . . . . . . . . . . . . . . 5 4. Using Node and Link MSD Advertisements . . . . . . . . . . . 6
5. Using Node and Link MSD Advertisements . . . . . . . . . . . 5 5. Base MPLS Imposition MSD . . . . . . . . . . . . . . . . . . 6
6. Base MPLS Imposition MSD . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
8. Security Considerations . . . . . . . . . . . . . . . . . . . 7 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 10.1. Normative References . . . . . . . . . . . . . . . . . . 7
11.1. Normative References . . . . . . . . . . . . . . . . . . 7 10.2. Informative References . . . . . . . . . . . . . . . . . 8
11.2. Informative References . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction 1. Introduction
When Segment Routing(SR) paths are computed by a centralized When Segment Routing(SR) paths are computed by a centralized
controller, it is critical that the controller learns the Maximum SID controller, it is critical that the controller learns the Maximum SID
Depth(MSD) that can be imposed at each node/link a given SR path to Depth(MSD) that can be imposed at each node/link on a given SR path
insure that the SID stack depth of a computed path doesn't exceed the to insure that the SID stack depth of a computed path doesn't exceed
number of SIDs the node is capable of imposing. the number of SIDs the node is capable of imposing.
The PCEP SR extensions draft [I-D.ietf-pce-segment-routing] signals The PCEP SR extensions draft [I-D.ietf-pce-segment-routing] signals
MSD in SR PCE Capability TLV and METRIC Object. However, if PCEP is MSD in SR PCE Capability TLV and METRIC Object. However, if PCEP is
not supported/configured on the head-end of an SR tunnel or a not supported/configured on the head-end of an SR tunnel or a
Binding-SID anchor node and controller does not participate in IGP Binding-SID anchor node and controller does not participate in IGP
routing, it has no way to learn the MSD of nodes and links which has routing, it has no way to learn the MSD of nodes and links. BGP-LS
been configured. BGP-LS [RFC7752] defines a way to expose topology [RFC7752] defines a way to expose topology and associated attributes
and associated attributes and capabilities of the nodes in that and capabilities of the nodes in that topology to a centralized
topology to a centralized controller. MSD signaling by BGP-LS has controller. MSD signaling by BGP-LS has been defined in
been defined in [I-D.ietf-idr-bgp-ls-segment-routing-msd]. [I-D.ietf-idr-bgp-ls-segment-routing-msd]. Typically, BGP-LS is
Typically, BGP-LS is configured on a small number of nodes that do configured on a small number of nodes that do not necessarily act as
not necessarily act as head-ends. In order for BGP-LS to signal MSD head-ends. In order for BGP-LS to signal MSD for all the nodes and
for all the nodes and links in the network MSD is relevant, MSD links in the network MSD is relevant, MSD capabilites should be
capabilites should be advertised to every OSPF router in the network. advertised by every OSPF router in the network.
Other types of MSD are known to be useful. For example, Other types of MSD are known to be useful. For example,
[I-D.ietf-ospf-mpls-elc] defines Readable Label Depth Capability [I-D.ietf-ospf-mpls-elc] defines Readable Label Depth Capability
(RLDC) that is used by a head-end to insert an Entropy Label (EL) at (RLDC) that is used by a head-end to insert an Entropy Label (EL) at
a depth that can be read by transit nodes. a depth that can be read by transit nodes.
This document defines an extension to OSPF used to advertise one or This document defines an extension to OSPF used to advertise one or
more types of MSD at node and/or link granularity. It also creates more types of MSD at node and/or link granularity. It also creates
an IANA registry for assigning MSD type identifiers. It laso defines an IANA registry for assigning MSD type identifiers. It also defines
the Base MPLS Imposition MSD type. In the future it is expected, the Base MPLS Imposition MSD type. In the future it is expected,
that new MSD types will be defined to signal additional capabilities that new MSD types will be defined to signal additional capabilities
e.g., entropy labels, SIDs that can be imposed through recirculation, e.g., entropy labels, SIDs that can be imposed through recirculation,
or SIDs associated with another dataplane e.g., IPv6. or SIDs associated with another dataplane e.g., IPv6. Although MSD
advertisements are associated with Segment Routing, the
advertisements MAY be present even if Segment Routing itself is not
enabled.
1.1. Conventions used in this document 1.1. Conventions used in this document
1.1.1. Terminology 1.1.1. Terminology
This memo makes use of the terms defined in [RFC7770]
BGP-LS: Distribution of Link-State and TE Information using Border BGP-LS: Distribution of Link-State and TE Information using Border
Gateway Protocol Gateway Protocol
BMI: Base MPLS Imposition is the number of MPLS labels that can be BMI: Base MPLS Imposition is the number of MPLS labels that can be
imposed inclusive of any service/transport labels imposed inclusive of all service/transport/special labels
OSPF: Open Shortest Path First OSPF: Open Shortest Path First
MSD: Maximum SID Depth - the number of SIDs a node or one of its MSD: Maximum SID Depth - the number of SIDs a node or one of its
links can support links can support
PCC: Path Computation Client PCC: Path Computation Client
PCE: Path Computation Element PCE: Path Computation Element
PCEP: Path Computation Element Protocol PCEP: Path Computation Element Protocol
SR: Segment Routing
SID: Segment Identifier SID: Segment Identifier
SR: Segment Routing LSA: Link state advertisement
RI: Router Information LSA
1.2. Requirements Language 1.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in "OPTIONAL" in this document are to be interpreted as described in
BCP14 [RFC2119], [RFC8174] when, and only when they appear in all BCP14 [RFC2119], [RFC8174] when, and only when they appear in all
capitals, as shown here . capitals, as shown here .
2. Terminology 2. Node MSD Advertisement
This memo makes use of the terms defined in [RFC4970].
3. Node MSD TLV
The node MSD TLV within the body of the OSPF RI Opaque LSA is defined The node MSD TLV within the body of the OSPF RI Opaque LSA is defined
to carry the provisioned SID depth of the router originating the RI to carry the provisioned SID depth of the router originating the RI
LSA. Node MSD is the minimum MSD supported by the node. LSA. Node MSD is the smallest MSD supported by the node on the set
of interfaces configured for use by the advertising IGP instance.
MSD values may be learned via a hardware API or may be provisioned..
0 1 2 3 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 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 | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Type and Value ... | MSD Type and Value ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ...
Figure 1: Node MSD TLV Figure 1: Node MSD TLV
The Type: TBD1 The Type: TBD1
Length: variable (minimum of 2, multiple of 2 octets) and represents Length: variable (minimum of 2, multiple of 2 octets) and represents
the total length of value field. the total length of value field.
Value: consists of a 1 octet sub-type (IANA Registry) and 1 octet Value: consists of one or more pairs of a 1 octet sub-type (IANA
value. Registry) and 1 octet value.
Sub-Type 1 (IANA Section), MSD and the Value field contains maximum MSD Type 1 (IANA Section), MSD and the Value field contains the MSD
MSD of the router originating the RI LSA. Node Maximum MSD is a of the originating router. Node MSD is a number in the range of
number in the range of 0-254. 0 represents lack of the ability to 0-255. 0 represents lack of the ability to impose MSD stack of any
impose MSD stack of any depth; any other value represents that of the depth; any other value represents that of the node. This value
node. This value SHOULD represent the minimum value supported by a SHOULD represent the minimum value supported by a node.
node.
Other Sub-types other than defined above are reserved for future Other MSD Types are reserved for future extensions.
extensions.
This TLV is applicable to OSPFv2 and to OSPFv3 [RFC5838] and is This TLV is applicable to OSPFv2 and to OSPFv3 [RFC5838] and is
optional. The scope of the advertisement is specific to the optional. The scope of the advertisement is specific to the
deployment. deployment.
4. Link MSD sub-TLV 3. Link MSD sub-TLV
A new sub-TLV called Link MSD sub-TLV is defined to carry the The link sub-TLV is defined to carry the MSD of the interface
provisioned SID depth of the interface associated with the link. associated with the link. MSD values may be learned via a hardware
API or may be provisioned.
0 1 2 3 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 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 | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Type and Value ... | MSD Type and Value ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ...
Figure 2: Link MSD Sub-TLV Figure 2: Link MSD Sub-TLV
Type: Type:
For OSPFv2, the Link level MSD value is advertised as an optional For OSPFv2, the Link level MSD value is advertised as an optional
Sub-TLV of the OSPFv2 Extended Link TLV as defined in [RFC7684], and Sub-TLV of the OSPFv2 Extended Link TLV as defined in [RFC7684], and
has value of TBD2. has value of TBD2.
For OSPFv3, the Link level MSD value is advertised as an optional For OSPFv3, the Link level MSD value is advertised as an optional
Sub-TLV of the Router-Link TLV as defined in Sub-TLV of the E-Router-LSA TLV as defined in [RFC8362], and has
[I-D.ietf-ospf-ospfv3-lsa-extend], and has value of TBD3. value of TBD3.
Length: variable and similar to what is defined in Section 3. Length: variable and similar to that, defined in Section 2.
Value: consists of a 1 octet sub-type (IANA Registry) and 1 octet Value: consists of one or more pairs of a 1 octet MSD Type (IANA
value. Registry) and 1 octet value.
Sub-Type 1 (IANA Section), MSD and the Value field contains Link MSD MSD Type 1 (IANA Section), MSD and the Value field contains Link MSD
of the router originating the corresponding LSA as specified for of the router originating the corresponding LSA as specified for
OSPFv2 and OSPFv3. Link MSD is a number in the range of 0-254. 0 OSPFv2 and OSPFv3. Link MSD is a number in the range of 0-255. 0
represents lack of the ability to impose MSD stack of any depth; any represents lack of the ability to impose MSD stack of any depth; any
other value represents that of the particular link MSD value. other value represents that of the particular link MSD value.
Other Sub-types other than defined above are reserved for future Other MSD Types are reserved for future extensions.
extensions.
5. Using Node and Link MSD Advertisements If these TLVs are advertised multiple times, only the first instance
of the TLV is used by receiving OSPF routers. This situation SHOULD
be logged as an error.
If these TLV is advertised multiple times for the same link in
different LSAs originated by the same OSPF router, the TLV with the
smallest Opaque ID/Link State ID is used by receiving OSPF routers.
This situation MAY be logged as a warning.
4. Using Node and Link MSD Advertisements
When Link MSD is present for a given MSD type, the value of the Link When Link MSD is present for a given MSD type, the value of the Link
MSD MUST take preference over the Node MSD. MSD MUST take preference over the Node MSD. When a Link MSD type is
not signalled but the Node MSD type is, then the value of that Link
MSD type MUST be considered as the corresponding Node MSD type value.
In order to increase flooding efficiency, it is RECOMMENDED, that
routers with homogenous link MSD values advertise just the Node MSD
value.
The meaning of the absence of both Node and Link MSD advertisements The meaning of the absence of both Node and Link MSD advertisements
for a given MSD type is specific to the MSD type. Generally it can for a given MSD type is specific to the MSD type. Generally it can
only be inferred that the advertising node does not support only be inferred that the advertising node does not support
advertisement of that MSD type. However, in some cases the lack of advertisement of that MSD type. However, in some cases the lack of
advertisement might imply that the functionality associated with the advertisement might imply that the functionality associated with the
MSD type is not supported. The correct interpretation MUST be MSD type is not supported. The correct interpretation MUST be
specified when an MSD type is defined. specified when an MSD type is defined.
6. Base MPLS Imposition MSD 5. Base MPLS Imposition MSD
The Base MPLS Imposition MSD (BMI-MSD) signals the total number of The Base MPLS Imposition MSD (BMI-MSD) signals the total number of
MPLS labels a node is capable of imposing, including any service/ MPLS labels a node is capable of imposing, including any service/
transport labels. transport labels.
Absence of BMI-MSD advertisements indicates solely that the Absence of BMI-MSD advertisements indicates solely that the
advertising node does not support advertisement of this capability. advertising node does not support advertisement of this capability.
7. IANA Considerations 6. IANA Considerations
This document requests IANA to allocate TLV type (TBD1) from the OSPF This document requests IANA to allocate TLV type (TBD1) from the OSPF
Router Information (RI) TLVs Registry as defined by [RFC4970]. IANA Router Information (RI) TLVs Registry as defined by [RFC4970]. IANA
has allocated the value 12 through the early assignment process. has allocated the value 12 through the early assignment process.
Also, this document requests IANA to allocate a sub-TLV type (TBD2) Also, this document requests IANA to allocate a sub-TLV type (TBD2)
from the OSPFv2 Extended Link TLV Sub-TLVs registry. IANA has from the OSPFv2 Extended Link TLV Sub-TLVs registry. IANA has
allocated the the value 6 through the early assignment process. allocated the the value 6 through the early assignment process.
Finally, this document requests IANA to allocate a sub-TLV type Finally, this document requests IANA to allocate a sub-TLV type
(TBD3) from the OSPFv3 Extended-LSA Sub-TLV registry. (TBD3) from the OSPFv3 Extended-LSA Sub-TLV registry.
This document requests creation of an IANA managed registry under a This document requests creation of an IANA managed registry under a
new category of "Interior Gateway Protocol (IGP) Parameters" IANA new category of "Interior Gateway Protocol (IGP) Parameters" IANA
registries to identify MSD types as proposed in Section 3, Section 4. registries to identify MSD types as proposed in Section 2, Section 3.
The registration procedure is "Expert Review" as defined in The registration procedure is "Expert Review" as defined in
[RFC8126]. The suggested registry name is "MSD types". Types are an [RFC8126]. The suggested registry name is "MSD types". Types are an
unsigned 8 bit number. The following values are defined by this unsigned 8 bit number. The following values are defined by this
document. document.
Value Name Reference Value Name Reference
----- --------------------- ------------- ----- --------------------- -------------
0 Reserved This document 0 Reserved This document
1 Base MPLS Imposition MSD This document 1 Base MPLS Imposition MSD This document
2-250 Unassigned This document 2-250 Unassigned This document
251-254 Experimental This document 251-254 Experimental This document
255 Reserved This document 255 Reserved This document
Figure 3: MSD Types Codepoints Registry Figure 3: MSD Types Codepoints Registry
8. Security Considerations 7. Security Considerations
Security considerations, as specified by [RFC7770] are applicable to Security concerns for OSPF are addressed in [RFC7474] and [RFC5310].
this document Further security analysis for OSPF protocol is done in [RFC6853]
including analysis of both the above documents. Security
considerations, as specified by [RFC7770] are applicable to this
document.
9. Contributors Advertisement of the additional information defined in this document
that is false, e.g. MSD that is incorrect may result: in a path
computation failing and the service unavailable or instantiation of a
path that can't be supported by the head-end (the node performing the
imposition).
8. Contributors
The following people contributed to this document: The following people contributed to this document:
Les Ginsberg Les Ginsberg
Email: ginsberg@cisco.com Email: ginsberg@cisco.com
10. Acknowledgements 9. Acknowledgements
The authors would like to thank Acee Lindem, Stephane Litkowski and The authors would like to thank Acee Lindem, Stephane Litkowski and
Bruno Decraene for their reviews and valuable comments. Bruno Decraene for their reviews and valuable comments.
11. References 10. References
11.1. Normative References 10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC4970] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and [RFC4970] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and
S. Shaffer, "Extensions to OSPF for Advertising Optional S. Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 4970, DOI 10.17487/RFC4970, July Router Capabilities", RFC 4970, DOI 10.17487/RFC4970, July
2007, <https://www.rfc-editor.org/info/rfc4970>. 2007, <https://www.rfc-editor.org/info/rfc4970>.
[RFC7770] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and [RFC7770] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and
S. Shaffer, "Extensions to OSPF for Advertising Optional S. Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 7770, DOI 10.17487/RFC7770, Router Capabilities", RFC 7770, DOI 10.17487/RFC7770,
February 2016, <https://www.rfc-editor.org/info/rfc7770>. February 2016, <https://www.rfc-editor.org/info/rfc7770>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
11.2. Informative References [RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and
F. Baker, "OSPFv3 Link State Advertisement (LSA)
Extensibility", RFC 8362, DOI 10.17487/RFC8362, April
2018, <https://www.rfc-editor.org/info/rfc8362>.
10.2. Informative References
[I-D.ietf-idr-bgp-ls-segment-routing-msd] [I-D.ietf-idr-bgp-ls-segment-routing-msd]
Tantsura, J., Chunduri, U., Mirsky, G., and S. Sivabalan, Tantsura, J., Chunduri, U., Mirsky, G., and S. Sivabalan,
"Signaling Maximum SID Depth using Border Gateway Protocol "Signaling Maximum SID Depth using Border Gateway Protocol
Link-State", draft-ietf-idr-bgp-ls-segment-routing-msd-01 Link-State", draft-ietf-idr-bgp-ls-segment-routing-msd-01
(work in progress), October 2017. (work in progress), October 2017.
[I-D.ietf-ospf-mpls-elc] [I-D.ietf-ospf-mpls-elc]
Xu, X., Kini, S., Sivabalan, S., Filsfils, C., and S. Xu, X., Kini, S., Sivabalan, S., Filsfils, C., and S.
Litkowski, "Signaling Entropy Label Capability and Litkowski, "Signaling Entropy Label Capability and
Readable Label-stack Depth Using OSPF", draft-ietf-ospf- Readable Label-stack Depth Using OSPF", draft-ietf-ospf-
mpls-elc-05 (work in progress), January 2018. mpls-elc-05 (work in progress), January 2018.
[I-D.ietf-ospf-ospfv3-lsa-extend]
Lindem, A., Roy, A., Goethals, D., Vallem, V., and F.
Baker, "OSPFv3 LSA Extendibility", draft-ietf-ospf-ospfv3-
lsa-extend-23 (work in progress), January 2018.
[I-D.ietf-pce-segment-routing] [I-D.ietf-pce-segment-routing]
Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W., Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W.,
and J. Hardwick, "PCEP Extensions for Segment Routing", and J. Hardwick, "PCEP Extensions for Segment Routing",
draft-ietf-pce-segment-routing-11 (work in progress), draft-ietf-pce-segment-routing-11 (work in progress),
November 2017. November 2017.
[RFC5838] Lindem, A., Ed., Mirtorabi, S., Roy, A., Barnes, M., and [RFC5838] Lindem, A., Ed., Mirtorabi, S., Roy, A., Barnes, M., and
R. Aggarwal, "Support of Address Families in OSPFv3", R. Aggarwal, "Support of Address Families in OSPFv3",
RFC 5838, DOI 10.17487/RFC5838, April 2010, RFC 5838, DOI 10.17487/RFC5838, April 2010,
<https://www.rfc-editor.org/info/rfc5838>. <https://www.rfc-editor.org/info/rfc5838>.
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