Network Working Group D. Dukes, Ed.
Internet-Draft C. Filsfils
Intended status: Standards Track Cisco Systems
Expires: August 26, 2021 G. Dawra
LinkedIn
X. Xu
Alibaba
D. Voyer
Bell Canada
P. Camarillo
F. Clad
Cisco Systems
S. Salsano
Univ. of Rome Tor Vergata
February 22, 2021
SR For SDWAN: VPN with Underlay SLA
draft-dukes-spring-sr-for-sdwan-03
Abstract
This document describes how SR enables underlay Service Level
Agreements (SLA) to a VPN with scale and security while ensuring
service opacity. This solution applies to Over-The-Top VPN (OTT VPN)
and Software-Defined WAN (SDWAN).
Status of This Memo
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This Internet-Draft will expire on August 26, 2021.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Notation . . . . . . . . . . . . . . . . . . . . 3
3. Single Provider . . . . . . . . . . . . . . . . . . . . . . . 3
3.1. Directly Connected CE to PE . . . . . . . . . . . . . . . 3
3.2. Best-effort Underlay Transport . . . . . . . . . . . . . 5
3.3. SR for Underlay SLA Differentiation . . . . . . . . . . . 6
3.4. Accounting . . . . . . . . . . . . . . . . . . . . . . . 8
3.5. Security . . . . . . . . . . . . . . . . . . . . . . . . 8
3.6. Remotely Connected (to PE) . . . . . . . . . . . . . . . 8
4. Multiple Providers . . . . . . . . . . . . . . . . . . . . . 8
5. Control Plane . . . . . . . . . . . . . . . . . . . . . . . . 9
6. Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. Scale . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.2. Privacy . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.3. Flexible Billing . . . . . . . . . . . . . . . . . . . . 12
6.4. Security . . . . . . . . . . . . . . . . . . . . . . . . 12
7. Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.1. Single Provider Example Using End.BM With an MPLS Core . 12
7.1.1. Accounting . . . . . . . . . . . . . . . . . . . . . 14
7.1.2. Security . . . . . . . . . . . . . . . . . . . . . . 14
7.2. Single Provider Example Using MPLS From CE to PE for BSID 14
7.3. Single Provider Example Using SRMPLS Over UDP For CE to
PE Not Directly Connected Over Internet . . . . . . . . . 14
7.3.1. Accounting . . . . . . . . . . . . . . . . . . . . . 15
7.3.2. Security . . . . . . . . . . . . . . . . . . . . . . 15
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
9. Security Considerations . . . . . . . . . . . . . . . . . . . 15
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Informative References . . . . . . . . . . . . . . . . . 15
10.2. Normative References . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
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1. Introduction
This document describes how SR enables underlay SLA to a VPN with
scale and security while ensuring service opacity. This solution
applies to Over-The-Top VPN (OTT VPN) with SLA differentiation, and
Software-Defined WAN (SDWAN) with SLA differentiation.
The body of this text uses SRv6 for illustration. A similar solution
leveraging SR-MPLS is illustrated in an appendix.
This document assumes familiarity with the following IETF documents:
o Segment Routing Architecture [I-D.ietf-spring-segment-routing]
o Segment Routing with MPLS data plane
[I-D.ietf-spring-segment-routing-mpls]
o IPv6 Segment Routing Header [RFC8754]
o SRv6 Network Programming
[I-D.filsfils-spring-srv6-network-programming]
o Segment Routing Policy For Traffic Engineering
[I-D.filsfils-spring-segment-routing-policy]
o IS-IS Extensions to Support Segment Routing over IPv6 Dataplane
[I-D.bashandy-isis-srv6-extensions]
For clarity, this version of the document uses the SDWAN example with
SRv6 to illustrate how SR can be used to provide underlay SLA to
overlay services. The journey of a packet from the left site to the
right site of the SDWAN Overlay is described. The solution applies
similarly for the return path.
2. Requirements Notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
3. Single Provider
3.1. Directly Connected CE to PE
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+------------+ /-----------/
| SDWAN | / /
| Control | / [SDWAN-C]...
+------------+ / / :
/-----------/ :
:
/-------------------------------------------/ :
+---------+ / / :
| SDWAN | / [A]-----[E1]***********[E2]--------[Z] / :
| Overlay | / : : / :
+---------+/ :...... : / :
/-----------------------:--------:----------/ :
: : :
: : :
/----------/ : : :
+------------+ / / : : :
| SP | / [SR-C] / : : :
| Control | / : / : : :
+------------+ /------:---/ ....: .. :
: : : :
: : : :
+------------+ : /---:-------------:-------------/ :
| SP | : / : : / :
| Underlay | : / [C1]----------[C2] / :
+------------+ :/ \ / / :
: \ /--/ / :
/: \ / / :
/ :...........[C3]..........................:
/ /
/-------------------------------/
**** = logical connection
:... = physical connection, between layers
/--\ = physical connection, within a layer
Figure 1: SDWAN Reference Diagram
An SDWAN overlay is composed of two sites A and Z, connected to the
Internet via edge nodes E1 and E2 respectively. E1 and E2 (customer
edge nodes) are connected via a Service Provider (SP) underlay to
form the VPN between the sites.
C1, C2 and C3 are nodes of the SP underlay, where C1 and C2 are
Provider Edge nodes. ISIS is deployed in the SP underlay with the
same cost on each link.
E1 and E2 connect to C1 and C2 respectively. The shortest path from
C1 to C2 is the best-effort path. The explicit path C1-C3-C2 is the
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low-latency path. By default, traffic transported from C1 to C2
follows the best-effort path. By default, an SDWAN cannot benefit
from the low-latency path from C1 to C2.
The address of A is 10.10.0.10/32 and the address of Z is
10.26.0.26/32. E1 and E2 respectively advertise 10.10/16 and
10.26/16 to the SDWAN controller SDWAN-C via a secure channel over
the Internet. The solution is applicable to any traffic exchanged
between the sites, including IPv4, IPv6 or L2. For clarity, a single
example with IPv4 in the SDWAN Overlay is used.
The SP operates an SR controller SR-C capable of computing
constrained paths from C1 to C2.
3.2. Best-effort Underlay Transport
Let's consider the path taken by traffic from A to Z, across the
SDWAN, between nodes E1 and E2 with addresses E1:: and E2::
respectively.
Host A sends a packet P to Z via E1. Packet P has source address
10.10.0.10 and destination address 10.26.0.26, illustrated as P
(10.10.0.10,10.26.0.26)(payload). E1, upon receipt of P, determines
E2 is the edge node to be used to reach Z. Edge node E1 encrypts,
encapsulates and forwards the packet P toward E2 and Z, and it is
handled as follow:
o Between A and E1 : P (10.10.0.10,10.26.0.26)(Payload)
o Between E1 and C1 : P
(E1::,E2::,NH=ESP)(NH=IPv4,(10.10.0.10,10.26.0.26)(Payload))
* Note that ESP tunnel mode encapsulation, encryption and
authentication is assumed but not required.
o Between C1 and C2 : P
(E1::,E2::,NH=ESP)(NH=IPv4,(10.10.0.10,10.26.0.26)(Payload))
o Between C2 and E2 : P (E1::,E2::,NH=ESP)(
NH=IPv4,(10.10.0.10,10.26.0.26)(Payload))
o Between E2 and Z : P (10.10.0.10,10.26.0.26)(Payload)
This example illustrates that, classically (i.e., without the SR
solution described in this document), the SDWAN cannot leverage the
rich infrastructure of the SP to meet its needs. The SP is
constrained to offer best-effort transit which does not reflect the
capabilities of its infrastructure.
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3.3. SR for Underlay SLA Differentiation
SR enables the SDWAN to steer selected flows through selected
transport paths of the SP, using the same example in Figure 1.
This small example, with only 3 SP routers, assumes all three support
SRv6. As explained in
[I-D.filsfils-spring-srv6-network-programming], a typical deployment
would only require SRv6 at a few strategic waypoints deployed through
the network.
It also assumes ISIS supports the lightweight SRv6 extension
described in [I-D.bashandy-isis-srv6-extensions].
The illustration convention from
[I-D.filsfils-spring-srv6-network-programming] is used such that:
o SRv6 SID Cj:: is explicitly instantiated at node Cj and bound to
the END.PSP function.
o SRv6 SID C1::B21 is a Binding SID (BSID) explicitly instantiated
at headend C1 and bound to the SRTE policy <C3::, C2::> toward
endpoint C2.
* Note the return direction would use a BSID C2::B11, bound at
headend C2, to the SRTE policy <C3::, C1::> toward endpoint C1.
The Control-Plane (CP) workflow that leads to the instantiation of
this Binding SID will be explained in the Control-Plane section.
Let's again consider the path from A to Z for a packet P, but this
time E1 has been configured by SDWAN-C to steer packet P into a
preferred low-latency path of the SP bound to the binding SID C1:B21.
o Between A and E1
* P (10.10.0.10,10.26.0.26)(payload)
o Between E1 and C1
* P (E1::,C1::B21; NH=SRH)(E2::,C1::B21; SL=1;
NH=ESP)(NH=IPv4(10.10.0.10,10.26.0.26)(Payload))
When the Binding SID C1::B21 is processed at C1, the SR TE Policy is
selected and the SRH for SID list <C3::,C2::> is inserted into P:
o Between C1 and C3
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* P (E1::,C3::;NH=SRH)(E2::,C2::,C3::; SL=2;NH=ESP)
(NH=IPv4(10.10.0.10,10.26.0.26)(Payload))
At C3, the SegmentsLeft is decremented as the END SID C3:: is
processed, and C2:: is placed in the destination address:
o Between C3 and C2
* P (E1::,C2::;NH=SRH)(E2::,C2::,C3::; SL=1;NH=ESP)
(NH=IPv4(10.10.0.10,10.26.0.26)(Payload))
At C2, the SegmentsLeft is decremented to 0, and penultimate segment
pop is applied as the END SID C2:: is processed and E2:: is placed in
the destination address while the SRH is removed:
o Between C2 and E2
* P (E1::,E2::,NH=ESP)(NH=IPv4(10.10.0.10,10.26.0.26)(Payload))
Finally, E2 decrypts the packet and strips the outer header to
forward the original packet to Z:
o Between E2 and Z
* P (10.10.0.10,10.26.0.26)(Payload)
The SDWAN edge nodes (E1,E2) maintain their existing behavior of
o Ingress Edge Node: classify ingress traffic, determining the
egress edge node, selecting a local output interface, secure the
traffic, and forward to the chosen egress edge node.
o Egress Edge Node: decapsulate, decrypt and forward on the internal
network.
The only change is that the Ingress node now monitors and selects an
SRv6 binding SID then pushes an SRH with two SIDs.
Note as well that the ingress and egress edge nodes never see the
actual SID list used by the SP to deliver the preferred path. A
variation of this design allows for the BSID to be kept in the packet
so that the egress node can detect which packets have been steered on
which preferred path (for accounting or monitoring purposes).
This is a fairly simple example of how SRv6 binding SIDs and SR TE
policies may be used to provide multiple diverse paths for SDWAN
traffic traversing a single provider network.
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3.4. Accounting
As per SRv6 network programming
[I-D.filsfils-spring-srv6-network-programming], each SRTE policy and
its bound BSID is associated with a unique traffic counter. This
allows the SP to implement various forms of billing and reporting to
the customer of the preferred path.
3.5. Security
The domain of trust security solution documented in
[I-D.filsfils-spring-srv6-network-programming] is utilized.
Specifically SEC1, SEC2 and SEC3 guarantee that external traffic to
the SP cannot exercise the SID's of the SP.
The following behavior is added: the ACL implementing SEC1 and SEC2
on node C1 is updated to specifically allow traffic from E1:: to
C1::B21.
Only the SDWAN edge that has ordered the preferential service can use
it.
Any other customer of the SP is unable to use the preferential path
bound to BSID C1::B21.
The SDWAN site that has ordered the preferential service is unable to
directly program the network of the SP using the internal SID's of
the SP. The SDWAN edge node is restricted to the BSID, which
opacifies the SP operation.
3.6. Remotely Connected (to PE)
Well known authentication technology with details provided in
subsequent revisions will be added, detailing the scenario with SDWAN
edge nodes not directly connected to the SP node terminating the
binding SID.
4. Multiple Providers
Well known authentication technology with details provided in
subsequent revisions will be added, detailing the scenario with SDWAN
edge nodes connected to the SP node offering binding SID via an
intermediate SP.
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5. Control Plane
The SDWAN overlay in Figure 1 is managed by an SDWAN controller,
SDWAN-C.
The control protocols used by the SDWAN-C to signal the site routes,
the BSID's and the site policies (which traffic on which BSID when)
securely over the SP network to E1 and E2 is outside the scope of
this document.
The SP underlay operates its internal SR deployment with an SR
controller (SR-C). SR-C interacts with the SP's network (Cj) through
standardized protocols (PCE[RFC4674] , PCEP [RFC5440]/[RFC4657], BGP
RR[RFC4456], BGP-TE [I-D.ietf-idr-segment-routing-te-policy], BGP-LS
[RFC7752])
Most likely, the SP would operate its underlay SLA service with a
service controller (SERV-C) that is separate from SR-C. To simplify
the illustration, this text assumes that SERV-C and SR-C are
integrated.
This section describes the high-level interaction between these
controllers for the low-latency use-case described in this document,
where an enterprise operator installs a policy in the SDWAN-C
requiring a low latency service between E1 and E2.
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+----------+
|Enterprise|
| Operator |
+----------+
+---+ | +----------+ +-------+ +---+
|E1 | | | SDWAN-C | | SR-C | |C1 |
+---+ | +----------+ +-------+ +---+
| | | | |
| |-------i----->| | |
| |Require low | | |
| |latency from | | |
| |E1 to E2 for | | |
| |some traffic | | |
| | +------ii----> |
| | request service |----+ |
| | from E1:: to | iii |
| | E2:: for low |<---+ |
| | latency |Compute an SR|
| | | |Policy for E1|
| | |to E2 |
| | | |
| | |-----iv----->|
| | | Program SR TE
| | | Policy |
| | | |
| | |<-----v------+
| |<----vi-----| Report policy
| |reply with | installed |
| |binding SID | |
|<-------vii----------|C1:B21::
| Notify |
| SID C1:B21:: |
| for low latency
| E1:: to E2::
|
Figure 2: Controlplane Flow
(i) The enterprise operator requests a low-latency path from site
E1 to site E2. It defines which traffic needs to be steered
on this preferred path.
(ii) SDWAN-C requests a low-latency service from SR-C for the
public address of E1 to the public address of E2.
(iii) SR-C computes an SR Policy to satisfy SDWAN-C's request:
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A. SR-C maps the E1 and E2 addresses to its managed nodes C1
and C2.
B. SR-C statefully registers the SRTE policy from C1 to C2
for low-latency.
C. SR-C computes the SID list fulfilling the SLA requirement
(e.g. <C3::, C2::>). The stateful nature of the SRTE
policy ensures that the SID list is updated whenever
required due to network state change.
D. SR-C binds a stable Binding SID C1::B21 to the SRTE
policy.
(iv) SR-C programs C1 with the computed SRTE policy and the
selected BSID. Standardized protocols such as
[I-D.ietf-idr-segment-routing-te-policy] or [RFC5440] are
used.
(v) C1 installs the policy in its dataplane and reports the
status of the SRTE policy to SR-C using standardized
protocols [RFC7752] or [RFC5440] and
[I-D.negi-pce-segment-routing-ipv6].
(vi) SR-C replies to SDWAN-C with BSID C1::B21
(vii) SDWAN-C programs E1 with the flow classification and steering
policy to insert SRv6 SID C1::B21 on the appropriate traffic
6. Benefits
6.1. Scale
The SP network does not hold any per-SDWAN-flow state in the core of
its network.
The SP network does not hold any complex L3-L7 flow classification at
the edge of its network.
The SP network is unaware of any policy change of the SDWAN instance
either in terms of which flow to classify, when to steer it and on
which path.
The SP's role only consists in statefully maintaining SRTE policies
at the edge of the network and maintaining a few 100's of SID's
inside its core network. This is the stateless property of Segment
Routing.
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6.2. Privacy
The SP network does not share any information of its infrastructure,
topology, capacity, internal SID's.
The SDWAN instance does not share any information on its traffic
classification, steering policy and business logic.
6.3. Flexible Billing
The traffic destined to a BSID is individually accounted
[I-D.filsfils-spring-srv6-network-programming].
The SP and SDWAN instance can agree on various forms of billing for
the usage of the preferential path.
6.4. Security
By default, the SP's SR infrastructure is protected by the simple
domain of trust solution documented in
[I-D.filsfils-spring-srv6-network-programming].
A BSID (and the related preferential path) can only be accessed by
the specific SDWAN instance (and site) that ordered the service.
The security solution supports any SDWAN site connection type:
directly connected to the SP edge or not.
7. Appendix
7.1. Single Provider Example Using End.BM With an MPLS Core
Reusing the example from Section 3.3, with an SP core that supports
SR MPLS as defined in [I-D.ietf-spring-segment-routing-mpls]. Each
node C1, C2 and C3 have node-SIDs defined, resulting in labels 16001,
16002, and 16003 respectively. In such a case a packet from A to Z
has an SRv6 binding SID applied, associated with an SR policy at node
C1. Node C1 translates the binding SID to an MPLS label stack which
is pushed on the packet.
For example:
o SRv6 SID C1::B22 is a Binding SID (BSID) explicitly instantiated
at headend C1 and bound to the SRTE policy <16003,16002> toward
endpoint C2.
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* Note the return direction would use a BSID C2::B12, bound at
headend C2, to the SRTE policy <16003, 16001> toward endpoint
C1.
Let's again consider the path from A to Z for a packet P where E1 has
been configured by SDWAN-C to steer packet P into a preferred low-
latency path of the SP bound to the binding SID C1::B22.
o Between A and E1
* P (10.10.0.10,10.26.0.26)(payload)
o Between E1 and C1
* P (E1::,C1::B22; NH=SRH)(E2::,C1::B22; SL=1;
NH=ESP)(NH=IPv4(10.10.0.10,10.26.0.26)(Payload))
When the Binding SID C1::B22 is processed at C1, the SR TE Policy is
selected and the label stack for SID list <16003,16002> is pushed on
P. In practice 16003 is not pushed on the wire since it has been
distributed with PHP:
o Between C1 and C3
* P (16002)(E1::,E2::;NH=ESP)
(NH=IPv4(10.10.0.10,10.26.0.26)(Payload))
At C3, 16002 is popped and PHP requires no new label be pushed as P
is forwarded via the link to C2:
o Between C3 and C2
* P (E1::,E2::;NH=ESP)(NH=IPv4(10.10.0.10,10.26.0.26)(Payload))
At C2, there is no more label stack so it forwards E2:: using the
global IPv6 table toward E2:
o Between C2 and E2
* P (E1::,E2::,NH=ESP)(NH=IPv4(10.10.0.10,10.26.0.26)(Payload))
Finally, E2 decrypts the packet and strips the outer header to
forward the original packet to Z:
o Between E2 and Z
* P (10.10.0.10,10.26.0.26)(Payload)
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Again the only change is that the Ingress node now selects an MPLS
binding SID for traffic taking the lowest latency path. The Ingress
node has no knowledge of the SP underlay.
7.1.1. Accounting
As defined in Section 3.4
7.1.2. Security
The SRv6 SID is secured as defined in Section 3.5
MPLS is not enabled on the CE-to-PE link.
7.2. Single Provider Example Using MPLS From CE to PE for BSID
To be completed in future revisions
7.3. Single Provider Example Using SRMPLS Over UDP For CE to PE Not
Directly Connected Over Internet
Reusing the example from Section 3.3, with an SP core that supports
the SR MPLS extensions defined in
[I-D.ietf-isis-segment-routing-extensions]. Each node C1, C2 and C3
have node-SIDs defined, resulting in labels 16001, 16002, and 16003
respectively.
Let's again consider the path from A to Z for a packet P, but this
time E1 has been configured by SDWAN-C to steer packet P into a
preferred low-latency path of the SP bound to an MPLS binding SID.
For example:
o MPLS label 24102 is a Binding SID (BSID) explicitly instantiated
at headend C1 and bound to the SRTE policy <16003,16002> toward
endpoint C2.
* Note the return direction would use a BSID 24201, bound at
headend C2, to the SRTE policy <16003, 16001> toward endpoint
C1.
Let's again consider the path from A to Z for a packet P where E1 has
been configured by SDWAN-C to steer packet P into a preferred low-
latency path of the SP bound to the binding SID 24102.
o Between A and E1
* P (10.10.0.10,10.26.0.26)(payload)
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o Between E1 and C1, RFC7510 UDP encapsulation of MPLS is used to
transport the MPLS labeled traffic.
* P (E1::,C1::; NH=UDP)(24102,(10.10.0.10,10.26.0.26)(Payload))
When C1 receives P, it decapsulates the UDP header and pops the
Binding SID 24102, the SR TE Policy is selected and the label stack
for SID list <16003,16002> is pushed on P. In practice, 16003 is not
pushed on the wire since it has been distributed with PHP.
The remainder of this use case is identical to Section 7.1. The only
change is that the Ingress node now uses an MPLS binding SID
transported over UDP instead of an SRv6 binding SID, allowing the use
of an IPv6 or IPv4 transport from CE to PE.
7.3.1. Accounting
As defined in Section 3.4
7.3.2. Security
[RFC7510] defines the use of DTLS to authenticate and encrypt the
MPLS in UDP encapsulation between CE and PE. The authentication
ensures the source is authorized to send traffic to a binding SID.
After the source is verified as authorized, the source address and
Binding SID SHOULD be checked to determine if the source is permitted
to use the specific Binding SID in the MPLS label.
MPLS is not enabled on the CE-to-PE link.
8. IANA Considerations
No current considerations.
9. Security Considerations
A domain of trust is secured via methods documented in
[I-D.filsfils-spring-srv6-network-programming]
10. References
10.1. Informative References
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[I-D.bashandy-isis-srv6-extensions]
Psenak, P., Filsfils, C., Bashandy, A., Decraene, B., and
Z. Hu, "IS-IS Extensions to Support Routing over IPv6
Dataplane", draft-bashandy-isis-srv6-extensions-05 (work
in progress), March 2019.
[I-D.filsfils-spring-segment-routing-policy]
Filsfils, C., Sivabalan, S., Hegde, S.,
daniel.voyer@bell.ca, d., Lin, S., bogdanov@google.com,
b., Krol, P., Horneffer, M., Steinberg, D., Decraene, B.,
Litkowski, S., Mattes, P., Ali, Z., Talaulikar, K., Liste,
J., Clad, F., and K. Raza, "Segment Routing Policy
Architecture", draft-filsfils-spring-segment-routing-
policy-06 (work in progress), May 2018.
[I-D.ietf-idr-segment-routing-te-policy]
Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P.,
Rosen, E., Jain, D., and S. Lin, "Advertising Segment
Routing Policies in BGP", draft-ietf-idr-segment-routing-
te-policy-11 (work in progress), November 2020.
[I-D.ietf-isis-segment-routing-extensions]
Previdi, S., Ginsberg, L., Filsfils, C., Bashandy, A.,
Gredler, H., and B. Decraene, "IS-IS Extensions for
Segment Routing", draft-ietf-isis-segment-routing-
extensions-25 (work in progress), May 2019.
[I-D.ietf-spring-segment-routing]
Filsfils, C., Previdi, S., Ginsberg, L., Decraene, B.,
Litkowski, S., and R. Shakir, "Segment Routing
Architecture", draft-ietf-spring-segment-routing-15 (work
in progress), January 2018.
[I-D.ietf-spring-segment-routing-mpls]
Bashandy, A., Filsfils, C., Previdi, S., Decraene, B.,
Litkowski, S., and R. Shakir, "Segment Routing with MPLS
data plane", draft-ietf-spring-segment-routing-mpls-22
(work in progress), May 2019.
[I-D.negi-pce-segment-routing-ipv6]
Negi, M., Li, C., Sivabalan, S., and P. Kaladharan, "PCEP
Extensions for Segment Routing leveraging the IPv6 data
plane", draft-negi-pce-segment-routing-ipv6-04 (work in
progress), February 2019.
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[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/info/rfc2119>.
[RFC4456] Bates, T., Chen, E., and R. Chandra, "BGP Route
Reflection: An Alternative to Full Mesh Internal BGP
(IBGP)", RFC 4456, DOI 10.17487/RFC4456, April 2006,
<https://www.rfc-editor.org/info/rfc4456>.
[RFC4657] Ash, J., Ed. and J. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol Generic
Requirements", RFC 4657, DOI 10.17487/RFC4657, September
2006, <https://www.rfc-editor.org/info/rfc4657>.
[RFC4674] Le Roux, J., Ed., "Requirements for Path Computation
Element (PCE) Discovery", RFC 4674, DOI 10.17487/RFC4674,
October 2006, <https://www.rfc-editor.org/info/rfc4674>.
[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/info/rfc5440>.
[RFC7510] Xu, X., Sheth, N., Yong, L., Callon, R., and D. Black,
"Encapsulating MPLS in UDP", RFC 7510,
DOI 10.17487/RFC7510, April 2015,
<https://www.rfc-editor.org/info/rfc7510>.
[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/info/rfc7752>.
[RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
<https://www.rfc-editor.org/info/rfc8754>.
10.2. Normative References
[I-D.filsfils-spring-srv6-network-programming]
Filsfils, C., Camarillo, P., Leddy, J.,
daniel.voyer@bell.ca, d., Matsushima, S., and Z. Li, "SRv6
Network Programming", draft-filsfils-spring-srv6-network-
programming-07 (work in progress), February 2019.
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Authors' Addresses
Darren Dukes (editor)
Cisco Systems
Canada
Email: ddukes@cisco.com
Clarence Filsfils
Cisco Systems
Belgium
Email: cfilsfil@cisco.com
Gaurav Dawra
LinkedIn
USA
Email: gdawra@linkedin.com
Xiaohu Xu
Alibaba
China
Email: xiaohu.xxh@alibaba-inc.com
Daniel Voyer
Bell Canada
Canada
Email: daniel.voyer@bell.ca
Pablo Camarillo Garvia
Cisco Systems
Spain
Email: pcamaril@cisco.com
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Francois Clad
Cisco Systems
France
Email: fclad@cisco.com
Stefano Salsano
Univ. of Rome Tor Vergata
Italy
Email: stefano.salsano@uniroma2.it
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