Multipath Traffic Engineering for Segment Routing
draft-stone-spring-mpte-sr-00
This document is an Internet-Draft (I-D).
Anyone may submit an I-D to the IETF.
This I-D is not endorsed by the IETF and has no formal standing in the
IETF standards process.
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Active".
|
|
|---|---|---|---|
| Authors | Andrew Stone , Vishnu Pavan Beeram | ||
| Last updated | 2025-06-30 | ||
| RFC stream | (None) | ||
| Formats | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-stone-spring-mpte-sr-00
Source Packet Routing in Networking A. Stone
Internet-Draft Nokia
Intended status: Standards Track V. P. Beeram
Expires: 1 January 2026 Juniper Networks
30 June 2025
Multipath Traffic Engineering for Segment Routing
draft-stone-spring-mpte-sr-00
Abstract
This document describes a mechanism to achieve Multipath Traffic
Engineering for Segment Routing based networks.
Discussion Venues
This note is to be removed before publishing as an RFC.
Discussion of this document takes place on the Source Packet Routing
in Networking Working Group mailing list (spring@ietf.org), which is
archived at https://mailarchive.ietf.org/arch/browse/spring/.
Source for this draft and an issue tracker can be found at
https://github.com/astone282/draft-stone-spring-mpte-sr.
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 https://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 1 January 2026.
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
Stone & Beeram Expires 1 January 2026 [Page 1]
Internet-Draft spring-mpte-sr June 2025
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://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 Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. MP-TE vs Multiple SID lists . . . . . . . . . . . . . . . . . 3
4. MP-TE concepts with Segment Routing . . . . . . . . . . . . . 4
4.1. MPTED . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2. Junction Segment . . . . . . . . . . . . . . . . . . . . 4
4.3. MPTE SR Policy - Tunnel with multiple ingress/egress . . 5
5. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Example . . . . . . . . . . . . . . . . . . . . . . . . . 7
6. Load-balancing . . . . . . . . . . . . . . . . . . . . . . . 10
7. Constraints . . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Protection . . . . . . . . . . . . . . . . . . . . . . . . . 10
9. Other considerations . . . . . . . . . . . . . . . . . . . . 10
9.1. Hierarchy . . . . . . . . . . . . . . . . . . . . . . . . 11
9.2. Directly connected Junction nodes . . . . . . . . . . . . 12
9.3. Broadcast links . . . . . . . . . . . . . . . . . . . . . 12
9.4. Local optimization . . . . . . . . . . . . . . . . . . . 12
9.5. Global optimization . . . . . . . . . . . . . . . . . . . 12
10. Security Considerations . . . . . . . . . . . . . . . . . . . 13
11. Manageability Considerations . . . . . . . . . . . . . . . . 13
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
13.1. Normative References . . . . . . . . . . . . . . . . . . 13
13.2. Informative References . . . . . . . . . . . . . . . . . 15
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
The document [I-D.draft-kompella-teas-mpte] introduces a multipath
traffic engineering concept that combines the benefits of both Equal-
Cost Multipath (ECMP) forwarding and traffic-engineered paths. This
approach uses a Directed Acyclic Graph (DAG) based forwarding
mechanism, with the DAG signaled to participating network nodes. The
concept is to move beyond simple ECMP paths by incorporating both
ECMP and non-ECMP paths while still adhering to traffic engineering
Stone & Beeram Expires 1 January 2026 [Page 2]
Internet-Draft spring-mpte-sr June 2025
constraints, to provide added resiliency while also permitting better
usage of link bandwidth.
[I-D.draft-kompella-teas-mpte] outlines the architecture design which
can be applied to both distributed and centralized signaling for
various tunnel types, including MPLS, IP, and others while leaving
the specific details of each out of scope.
This document proposes and discusses a centralized computation and
signaling mechanism for SR-based networks, primarily utilizing
existing constructs and capabilities. As MPTE evolves, new
extensions to SR-based documents may be needed, both in terms of
architecture and protocol-specific semantics.
The document assumes the reader is familiar with [RFC8402],
[RFC9256], and [I-D.draft-kompella-teas-mpte].
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Terminology
* For MPTE terminology such as MPTED, DAG, MC, MID, Junction node
and others see [I-D.draft-kompella-teas-mpte].
* For SR terminology see [RFC8402] and [RFC9256].
3. MP-TE vs Multiple SID lists
It's important to recognize the SR Policy information model supports
multiple SID lists, effectively encoding multiple unique paths on a
tunnel at the ingress. A Directed Acyclic Graph (DAG) can be
represented as a collection of individual paths, each of which can be
programmed as a separate SID list within an SR Policy Candidate Path.
However, depending on the graph topology, the number of unique paths
to encode can grow significantly. Additionally, in traditional SID
list approaches, hashing is performed only at the ingress, rather
than at each downstream node. In contrast, a DAG-based mechanism may
allow better traffic distribution or localized tuning based on
localized weight changes. Finally, the maximum segment depth (MSD)
may need to be considered for long paths that deviate significantly
from the shortest path.
Stone & Beeram Expires 1 January 2026 [Page 3]
Internet-Draft spring-mpte-sr June 2025
In comparison, encoding a DAG’s forwarding instructions across the
participating Junction nodes reduces the number of individual SID
lists at the ingress, but at the cost of increasing state in the
network. While source-based routing aims to reduce network state,
there is a trade-off between the volume and length of SID lists
versus distributing that state throughout the network to achieve
multipath traffic engineering use cases.
The choice between using multiple ingress segment lists or the MPTE
DAG-based distribution mechanism depends on the traffic engineering
requirements, overall network design, link/path metrics, and the
DAG’s structure.
4. MP-TE concepts with Segment Routing
This document proposes the below concepts for applying MPTE in an SR
environment.
4.1. MPTED
The MPTED is managed by a centralized controller, such as a PCE
acting as the MC. Topology discovery is performed using BGP-LS
[RFC7752], while transport control plane signaling is achieved
through controller-oriented protocols such as PCEP [RFC5440],
[RFC8231] and BGP/BGP-LS
[I-D.draft-ietf-idr-segment-routing-te-policy],
[I-D.draft-ietf-idr-bgp-ls-sr-policy]. The MC computes, manages, and
distributes all forwarding information to the nodes participating in
the MPTE DAG, which form the MPTED.
[I-D.draft-kompella-teas-mpte] specifies that a node in the MPTED is
identified by its IPv6 loopback address. However, this document
allows the use of a 32-bit dotted quad router ID as an alternative.
This value represents the headend address of a node participating in
the DAG.
As per [I-D.draft-kompella-teas-mpte], the controller acting as the
MC is responsible for assigning the MPID and incrementing the MPTED
unique ID version.
4.2. Junction Segment
The concept of a Junction Segment is introduced to describe the
signaling and forwarding behavior of a Junction node in an SR
network.
Stone & Beeram Expires 1 January 2026 [Page 4]
Internet-Draft spring-mpte-sr June 2025
It’s worth noting that the architectural use of a Junction Segment is
analogous to a Replication Segment [RFC9524], but it performs
forwarding based on load balancing rather than replication.
A Junction Segment is installed on nodes identified as Junction
Nodes, as defined in [I-D.draft-kompella-teas-mpte].
This document version proposes that a Junction Segment is realized
using the existing SR Policy construct with a single Candidate Path.
Future document versions may evolve the Junction segment into its own
explicit segment type as opposed to leveraging the existing SR Policy
constructs. A Binding Segment is attached to an SR Policy Candidate
Path with one or more SID Lists. OIF instruction signaling is
achieved via segment lists, where the top SID identifies the outgoing
interface(s).
Since a Junction Segment may egress to multiple downstream nodes, the
endpoint of the corresponding SR Policy MUST be set to the null value
(0.0.0.0). Therefore, a Junction segment is identified by its
<headend, color> attribute. This document currently assumes that the
color value be encoded with both the MID and version. However,
further updates may include additional encoding of these independent
values in the SR Policy model.
Since SR-based networks support specifying multiple egress interfaces
using adjacency-SID sets and Node SIDs, the Junction Segment MAY
include a SID list entry that identifies multiple outgoing
interfaces. In addition to egress interfaces,
[I-D.draft-kompella-teas-mpte] describes signaling ingress
interfaces. The use of a Junction Segment omits the need for per-
interface ingress signaling as a single Binding Segment attached to
an SR Policy is used. All upstream originated traffic sent to a
downstream Junction Node uses the same, single Junction Segment value
which is a Binding Segment.
4.3. MPTE SR Policy - Tunnel with multiple ingress/egress
[I-D.draft-kompella-teas-mpte] specifies that an MPTE Tunnel could
have multiple ingress and/or multiple egress nodes. Currently, the
SR Policy architecture defines an SR Policy using a {Headend,
Endpoint, Color} tuple, where the Endpoint may be set to the null
value (0.0.0.0), indicating multiple destinations.
For controller-initiated tunnels, the intended ingress and egress
node(s) can be provided to the controller based on implementation-
specific methods. These may be signaled to the network as multiple
tunnels to support multi-ingress scenarios. Each tunnel MAY use a
null Endpoint value to support multi-egress.
Stone & Beeram Expires 1 January 2026 [Page 5]
Internet-Draft spring-mpte-sr June 2025
However, MPTE SR Policies that are originated or defined by network
devices are typically limited to a single ingress and a single egress
endpoint unless protocols such as PCEP or NETCONF are extended to
encode additional intended destination node(s) for controller-based
path computation. Extensions to the SR Policy architecture may be
needed to support signaling of multiple intended destinations for
path computation.
Support for network-originated or device-defined MPTE SR Policies
with multiple ingress nodes is currently out of scope.
5. Operation
A path computation request or tunnel delegation notification is sent
to the controller, specifying one or more ingress and egress nodes,
along with constraints. This request may originate from an ingress
router in the network or be provisioned directly via an API to the
controller. This tunnel computation request or delegation pertains
to an instance of an MPTED, which is assigned an identifier and a
version.
The controller computes the DAG for ingress and all egress endpoints
to determine all Junction nodes in the DAG to be used for the tunnel.
The controller signals the Junction Segment to all downstream nodes,
starting with the penultimate egress hop node(s) and working upwards
toward the ingress nodes.
Junction Segment deployments are in the form of a unicast SR Policy
with a single Candidate Path using protocols such as PCEP, BGP, or
NETCONF. The optional use of an MPTED Reflector is protocol
specific. For example, PCEP sessions terminate on each and every
Junction node in the topology and BGP may do the same or make use of
a BGP Route Reflector. A BSID MUST be explicitly requested or
signaled to the Junction node for assignment. If the controller opts
for local node assigned value, it MUST wait to signal upstream
Junction nodes about their Junction segments in their outgoing SID
lists.
Stone & Beeram Expires 1 January 2026 [Page 6]
Internet-Draft spring-mpte-sr June 2025
Each SR Policy contains one or more SID lists. These SID lists must
include at least two segment identifiers: one SID for forwarding to
the downstream Junction node and one for the Junction Segment value
(BSID) of the downstream node. For directly connected neighbors,
this may be the adjacency or node SID for the neighbor. For Junction
nodes that are not directly connected, additional SIDs MAY be used to
steer the packet along an ECMP or non-ECMP path to the downstream
Junction node. It is worth noting that if the SID list comprises of
only an Adjacency-SID and the Junction SID of the neighbor node, then
the dataplane packet contains only one SID on egress which is the
Junction SID of the neighboring node.
5.1. Example
+------+ +------+
| | 10 | |
| B | ----- | E |
-- | | | |-\
10 -/ +------+ +------+ --\ 10
-/ | 10 -\
-/ | --
+------+ +------+ +------+ +------+
| | | | | | | |
| A | -----| C | ----- | F |---- | H |
| | 10 | | 5 | | 10 | |
+------+ +------+\ /+------+ +------+
-\ | |5 \ / 5|(Pruned) -/
--\ | | / \ | -/
20 -\ +------+/ \+------+ -/ 10
--| | 5 | | /
| D | ----- | G |
| | | |
+------+ +------+
Figure 1 : Example Topology to apply DAG
Figure 1 presents a sample topology for one ingress and one egress
MPTE Tunnel established as an SR Policy. The MPTE tunnel is from A
to H. The figure presents the bi-directional link weights for an
arbitrary metric (IGP, TE, Delay etc).
Note there is a mesh between C, D, F and G of weight 5 per link.
Pruned represents an excluded link due to TE constraints. In the
below, the terminology {u,v} represents a unidirectional link between
U and V. The terminology Adj-SID-XY represents an adjacency SID from
X to Y. Node-SID-X represents the node SID path to X.
Stone & Beeram Expires 1 January 2026 [Page 7]
Internet-Draft spring-mpte-sr June 2025
A MPTE DAG is computed to contain nodes B,C,D,E,F,G with the links
{G, F} / {F, G} pruned.
The below Junction Segments are deployed to the network realized with
an SR Policy with a single Candidate Path containing multiple segment
lists. Note the following:
* When the DAG is computed, loops cannot exist. Therefore, in the
above topology the links in direction {C, B} and {C,D} and {C,F}
and {C,G} are chosen in the DAG.
* The path along {B,E,H} can be represented by a single Node SID. A
Junction on node E is not required.
* Junction F is described below, but an optimization could be
performed to exclude Junction F as it only has one egress link. A
generalized mechanism to optimize the DAG distribution could omit
Junction segments if the Junction segment contains only one egress
SID list.
* In practice the Binding Segments MAY be all the same value. This
example describes different BSID values for readability.
* Weights of each egress SID list is also currently omitted.
Stone & Beeram Expires 1 January 2026 [Page 8]
Internet-Draft spring-mpte-sr June 2025
Junction Segment B:
BSID: BSID-B
SID List 1: [Node-SID-H]
Junction Segment F:
BSID: BSID-F
SID List 1: [Adj-SID-FH]
Junction Segment G:
BSID: BSID-G
SID List 1: [Adj-SID-GH]
Junction Segment C:
BSID: BSID-C
SID List 1: [Adj-SID-CB, BSID-B]
SID List 2: [Adj-SID-CF, BSID-F]
SID List 3: [Adj-SID-CG, BSID-G]
SID List 4: [Node-SID-D, BSID-D]
Junction Segment D:
BSID: BSID-D
SID List 2: [Adj-SID-DF, BSID-F]
SID List 3: [Adj-SID-DG, BSID-G]
Then lastly, at ingress the SR Policy transport tunnel is configured with the following:
Ingress SR Policy (Using Junction Segments):
Candidate Path 1:
SID List 1: [Adj-SID-AB, BSID-B]
SID List 2: [Adj-SID-AC, BSID-C]
SID List 3: [Adj-SID-AD, BSID-D]
In comparison, if the above DAG was encoded at ingress then the
following individual segment lists could be used to represent the
above DAG. Note, some of the below could be compressed with a Node
SID(s) but listed with adjacency for explicit example.
Ingress SR Policy (Ingress only):
Candidate Path 1:
SID List 1: [Adj-SID-AC, Adj-SID-CF, Adj-SID-FH]
SID List 2: [Adj-SID-AC, Node-SID-D, Adj-SID-DG, Adj-SID-GH]
SID List 3: [Adj-SID-AC, Node-SID-D, Adj-SID-DF, Adj-SID-FH]
SID List 4: [Adj-SID-AC, Adj-SID-CF, Adj-SID-CG, Adj-SID-GH]
SID List 5: [Adj-SID-AC, Adj-SID-CF, Adj-SID-BE, Adj-SID-EH]
SID List 6: [Adj-SID-AB, Node-SID-H]
SID List 7: [Adj-SID-AD, Adj-SID-DG, Adj-SID-GH]
SID List 8: [Adj-SID-AD, Adj-SID-DF, Adj-SID-FH]
Stone & Beeram Expires 1 January 2026 [Page 9]
Internet-Draft spring-mpte-sr June 2025
6. Load-balancing
When a packet with the BSID assigned to the Junction Segment is
received at its ingress, the node performs weighted ECMP forwarding
among all egress SID lists associated with the SR Policy.
It is worth noting that [I-D.draft-kompella-teas-mpte] introduces the
concepts of both unequal weight balancing and 0 weight to omit
forwarding out of an egress interface while maintaining the
instruction signaling. The 0 weight capability is not supported in
the current SR Policy model and may be considered in future updates
to this document.
7. Constraints
When the controller computes the DAG, traffic engineering constraints
MUST be considered. Links which violate the constraints are pruned
from the DAG. Nodes which do not form the DAG are not notified with
any Junction segments.
8. Protection
As described in [I-D.draft-kompella-teas-mpte], as there are multiple
egress interfaces (SID Lists), the loss of an interface link does not
result in traffic drops as long as one egress interface (SID List)
remains, although congestion may occur.
Link protection from an upstream Junction node to its downstream
Junction nodes can be achieved using existing TI-LFA
[I-D.draft-ietf-rtgwg-segment-routing-ti-lfa] mechanisms, applied per
egress SID List. Since the top SID(s) in each SID List identify the
path to the next downstream Junction node, TI-LFA is applicable.
Local computation for node protection on an upstream Junction node is
not feasible, because it lacks visibility into the DAG beyond the
immediate downstream Junction node as it only knows the next Junction
Segment. A controller MAY be used to precompute backup SR Paths and
signal these backup SID Lists to the upstream Junction segments.
In a situation where a downstream Junction node experiences system or
connectivity failure, the upstream Junction node will begin to
blackhole the traffic until a notification can be sent to upstream
nodes to remove the Junction node from the DAG.
9. Other considerations
Stone & Beeram Expires 1 January 2026 [Page 10]
Internet-Draft spring-mpte-sr June 2025
9.1. Hierarchy
The use of Junction Segments to achieve a DAG can be used in
hierarchical organization and sharing of DAGs between end-to-end
tunnels.
For instance, in a multi-area or multi-instance topology, one or more
shared DAGs may be created per area, connecting the border ingress
node(s) and egress node(s). These DAGs can then be stitched together
for use in an end-to-end SR tunnel.
Figure 2 is an example of two independent SR Policy Tunnels from
Headend A and Headend B terminating on Egress X. An instance of a
DAG with MID 100 can be configured between ABR-1 and the Egress X
node. ABR-1 Junction Segment which ingresses the DAG has a Binding
Segment attached, for example BSID-100. Therefore, the SID list on
Headend A and Headend B SID lists would contain the SR Path (ex:
Node-SID-ABR-1) to reach ABR 1 followed by BSID-100. The instruction
set from each Headend to ABR 1 could also be another instance of a
DAG, either for independent use or shared.
-------------------------------------------------------------
| | |
| | |
+-------+ | ---\ |
| |--\ Path 1 | ---/ | ---\ |
|Headend| ----\ | ---/ -----\ --\ |
| A | ----\ +-----+-/ ---/ ---\ --+------+
+-------+ ----\ | | --/ -------| -- | |
| --- | ABR | ------------------- |Egress|
| --- | 1 | |DAG-100 | X |
+-------+ ----/ +-----+ --\ | ----- +------+
| | -----/ | -\ ----\-------/ -- |
|Headend| ----/ | --\ --- --/ |
| B |--/ Path 2 | -\ | --/ |
+-------+ | --\ --/ |
| | ---/ |
| | |
-------------------------------------------------------------
Domain/Area 1 Domain/Area 2
Figure 2 : Reusable DAG 100
Stone & Beeram Expires 1 January 2026 [Page 11]
Internet-Draft spring-mpte-sr June 2025
9.2. Directly connected Junction nodes
As described in the Operational section, all transit nodes in a DAG
MAY be signaled with a Junction Segment. Alternatively depending on
the topological graph and TE requirements, two Junction segments may
be interconnected via an SR Path, with a SID list, where the SR Path
itself may correspond to an ECMP or TE Path.
9.3. Broadcast links
SR networks abstract broadcast links with the use point to point
adjacency segments identifying each neighbor. Specifying a DAG which
contains a broadcast link is feasible as an adjcency segment can be
used to identify the neighboring Junction node on the broadcast link.
The outgoing SID List of the Junction Segment simply contains the
adjacency SID of the next-hop neighbor on the broadcast link.
9.4. Local optimization
An individual Junction Segment can be optimized by adding new SID
lists for downstream neighbors in the DAG or removing downstream
nodes. Additionally, the SR path between two Junction nodes whether
directly or indirectly connected may also be updated. The controller
utilizes existing protocol mechanisms to update the forwarding
instructions of the Junction Segment.
Multiple candidate paths can be used to facilitate local
optimization. However, care must be taken regarding how the MPTED
version is encoded and how version increments are signaled.
Specifically, if the MPTED version is encoded in the color attribute
or another attribute of the SR Policy, rather than within the
Candidate Path itself, multiple Candidate Paths SHOULD NOT be used
when an operation requires incrementing the MPTED version to maintain
consistency.
The implications of MPTED version encoding and management will be
further addressed in future versions of this document.
9.5. Global optimization
Reoptimizing the DAG requires potentially redeploying all new
Junction Segments network wide in a coordinated, make before break
manner.
Since the DAG MID and version are encoded in the color field of an SR
Policy, globally optimizing a DAG with make-before-break
considerations requires deploying new Junction segments as SR
Policies with unique color values to all Junction nodes of the new
Stone & Beeram Expires 1 January 2026 [Page 12]
Internet-Draft spring-mpte-sr June 2025
DAG. After all of the new Junction segments are deployed, the
ingress node can be updated with new SID lists which utilize the new
DAG Junction segments of its's neighbors.
TODO This section needs further discussion.
TODO
10. Security Considerations
TODO
11. Manageability Considerations
This document currently proposes using the existing SR Policy
construct with a color value representing the DAG MID and version.
Since SR Policy color value is originally intended for ingress
traffic steering on matched routers, a deployment MUST allocate a
color range which will be used for MPTE and MUST NOT be assigned to
any advertised routes in the network.
TODO
12. IANA Considerations
None at this time
13. References
13.1. Normative References
[I-D.draft-ietf-idr-bgp-ls-sr-policy]
Previdi, S., Talaulikar, K., Dong, J., Gredler, H., and J.
Tantsura, "Advertisement of Segment Routing Policies using
BGP Link-State", Work in Progress, Internet-Draft, draft-
ietf-idr-bgp-ls-sr-policy-17, 6 March 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-bgp-
ls-sr-policy-17>.
[I-D.draft-ietf-idr-segment-routing-te-policy]
Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P., and
D. Jain, "Advertising Segment Routing Policies in BGP",
Work in Progress, Internet-Draft, draft-ietf-idr-segment-
routing-te-policy-26, 23 October 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-
segment-routing-te-policy-26>.
Stone & Beeram Expires 1 January 2026 [Page 13]
Internet-Draft spring-mpte-sr June 2025
[I-D.draft-ietf-rtgwg-segment-routing-ti-lfa]
Bashandy, A., Litkowski, S., Filsfils, C., Francois, P.,
Decraene, B., and D. Voyer, "Topology Independent Fast
Reroute using Segment Routing", Work in Progress,
Internet-Draft, draft-ietf-rtgwg-segment-routing-ti-lfa-
21, 12 February 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-rtgwg-
segment-routing-ti-lfa-21>.
[I-D.draft-kompella-teas-mpte]
Kompella, K., Jalil, L., Khaddam, M., and A. Smith,
"Multipath Traffic Engineering", Work in Progress,
Internet-Draft, draft-kompella-teas-mpte-00, 3 March 2025,
<https://datatracker.ietf.org/doc/html/draft-kompella-
teas-mpte-00>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol (PCEP)", RFC 5440,
DOI 10.17487/RFC5440, March 2009,
<https://www.rfc-editor.org/rfc/rfc5440>.
[RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and
S. Ray, "North-Bound Distribution of Link-State and
Traffic Engineering (TE) Information Using BGP", RFC 7752,
DOI 10.17487/RFC7752, March 2016,
<https://www.rfc-editor.org/rfc/rfc7752>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for Stateful PCE", RFC 8231,
DOI 10.17487/RFC8231, September 2017,
<https://www.rfc-editor.org/rfc/rfc8231>.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/rfc/rfc8402>.
Stone & Beeram Expires 1 January 2026 [Page 14]
Internet-Draft spring-mpte-sr June 2025
[RFC9256] Filsfils, C., Talaulikar, K., Ed., Voyer, D., Bogdanov,
A., and P. Mattes, "Segment Routing Policy Architecture",
RFC 9256, DOI 10.17487/RFC9256, July 2022,
<https://www.rfc-editor.org/rfc/rfc9256>.
13.2. Informative References
[RFC9524] Voyer, D., Ed., Filsfils, C., Parekh, R., Bidgoli, H., and
Z. Zhang, "Segment Routing Replication for Multipoint
Service Delivery", RFC 9524, DOI 10.17487/RFC9524,
February 2024, <https://www.rfc-editor.org/rfc/rfc9524>.
Acknowledgments
None at this time
Authors' Addresses
Andrew Stone
Nokia
Email: andrew.stone@nokia.com
Vishnu Pavan Beeram
Juniper Networks
Email: vbeeram@juniper.net
Stone & Beeram Expires 1 January 2026 [Page 15]