Network Working Group L. Dunbar
Internet Draft J. Kaippallimalil
Intended status: Standard Futurewei
Expires: April 27, 2021
October 27, 2020
IPv6 Solution for 5G Edge Computing Sticky Service
draft-dunbar-6man-5g-edge-compute-sticky-service-00
Abstract
This draft describes an IPv6 solution that enables packets from
an application on a UE (User Equipment) sticking to the same
application server location when the UE moves from one 5G cell
site to another.
Status of this Memo
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provisions of BCP 78 and BCP 79.
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Table of Contents
1. Introduction.................................................. 3
1.1. 5G Edge Computing Background................................ 3
1.2. Problem #1: ANYCAST in 5G EC Environment.................... 4
1.3. Problem #2: sticking to original App Server................. 5
1.4. Problem #3: Application Server Relocation................... 5
2. Conventions used in this document............................. 6
3. Proposed IPv6 Based Solution.................................. 7
3.1. Solution Overview........................................... 8
3.2. Ensure one IPv6 Flow Go to the Same Location................ 9
3.3. Discover the Egress Routers for App Servers................ 10
3.4. Using Destination Extension Header......................... 10
3.5. Using IPv6 Routing Extension Header........................ 13
4. Achieve Sticky Service without dependence on UE.............. 14
5. Forwarding to the desired A-ER without using Tunnel.......... 15
6. Manageability Considerations................................. 16
7. Security Considerations...................................... 17
8. IANA Considerations.......................................... 17
9. References................................................... 17
9.1. Normative References....................................... 17
9.2. Informative References..................................... 17
10. Acknowledgments............................................. 18
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1. Introduction
1.1. 5G Edge Computing Background
As described in [5G-EC-Metrics], one Application can have
multiple Application Servers hosted in different Edge Computing
data centers that are close in proximity. Those Edge Computing
(mini) data centers are usually very close to, or co-located
with, 5G base stations, with the goal to minimize latency and
optimize the user experience.
When a UE (User Equipment) initiates application packets using
the destination address from a DNS reply or from its own cache,
the packets from the UE are carried in a PDU session through 5G
Core [5GC] to the 5G UPF-PSA (User Plan Function - PDU Session
Anchor). The UPF-PSA decapsulate the 5G GTP outer header and
forwards the packets from the UEs to the Ingress router of the
Edge Computing (EC) Local Data Network (LDN). The LDN for 5G
EC, which is the IP Networks from 5GC perspective, is
responsible for forwarding the packets to the intended
destinations.
When the UE moves out of coverage of its current gNB (next
generation Node B) (gNB1), handover procedures are initiated
and the 5G SMF (Session Management Function) also selects a new
UPF-PSA. The standard handover procedures described in 3GPP TS
23.501 and TS 23.502 are followed. When the handover process is
complete, the UE has a new IP address and the IP point of
attachment is to the new UPF-PSA. 5GC may maintain a path from
the old UPF to new the UPF for a short period of time for SSC
[Session and Service Continuity] mode 3 to make the handover
process more seamless.
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+--+
|UE|---\+---------+ +------------------+
+--+ | 5G | +---------+ | S1: aa08::4450 |
+--+ | Site +--++---+ +----+ |
|UE|----| A |PSA| Ra| | R1 | S2: aa08::4460 |
+--+ | +---+---+ +----+ |
+---+ | | | | | S3: aa08::4470 |
|UE1|---/+---------+ | | +------------------+
+---+ |IP Network | L-DN1
|(3GPP N6) |
| | | +------------------+
| UE1 | | | S1: aa08::4450 |
| moves to | +----+ |
| Site B | | R3 | S2: aa08::4460 |
v | +----+ |
| | | S3: aa08::4470 |
| | +------------------+
| | L-DN3
+--+ | |
|UE|---\+---------+ | | +------------------+
+--+ | 5G | | | | S1: aa08::4450 |
+--+ | Site +--++-+--+ +----+ |
|UE|----| B |PSA| Rb | | R2 | S2: aa08::4460 |
+--+ | +--++----+ +----+ |
+--+ | | +-----------+ | S3: aa08::4470 |
|UE|---/+---------+ +------------------+
+--+ L-DN2
Figure 1: App Servers in different edge DCs
1.2. Problem #1: ANYCAST in 5G EC Environment
Increasingly, Anycast is used extensively by various
application providers and CDNs because it is possible to
dynamically load balance across multiple locations of the same
address based on network conditions. BGP is an integral part in
the way IP anycast usually functions. Within BGP routing there
are multiple routes for the same IP address which are pointing
to different locations.
Application Server location selection using Anycast address
leverages the proximity information present in the network
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(routing) layer and eliminates the single point of failure and
bottleneck at the DNS resolvers and application layer load
balancers. Another benefit of using ANYCAST address is removing
the dependency on UEs that use their cached IP addresses
instead of querying DNS when they move to a new location.
But, having multiple locations for the same ANYCAST address in
5G Edge Computing environment can be problematic because all
those edge computing Data Centers can be close in proximity.
There might not be any difference in the routing cost to reach
the Application Servers in different Edge DCs. Same routing
cost to multiple ANYCAST locations can cause packets from one
flow to be forwarded to different locations, which can cause
service glitches.
1.3. Problem #2: sticking to original App Server
When a UE moves to a new location but continues the same
application flow, routers at the new location might choose the
App Server closer to the new location. As shown in the figure
below, when the UE1 in 5G-site-A moves to the 5G-Site-B, the
router directly connected to 5G PSA2 might forward the packets
destined towards the S1: aa08::4450 to the instance located in
L-DN2 because L-DN2 has the lowest cost based on routing.
This is not the desired behavior for some services, which are
called Sticky Services in this document.
Even for some advanced applications with built-in mechanisms to
re-sync the communications at the application layer after
switching to a new location, service glitches are very often
experienced by users.
It worth noting that not all services need to be sticky. We
assume only a subset of services are, and the Network is
informed of the services that need to be sticky, usually by
requests from application developers or controllers.
This document describes an IPv6 based network layer solution to
stick the packets belonging to the same flow of a UE to its
original App Server location after the UE is anchored to a new
UPF-PSA.
1.4. Problem #3: Application Server Relocation
When an Application Server is added to, moved, or deleted from
a 5G Edge Computing Data Center, the routing protocol has to
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propagate the changes to 5G PSA or the PSA adjacent routers.
After the change, the cost associated with the site [5G-EC-
Metrics] might change as well.
Note: for the ease of description, the Edge Application Server
and Application Server are used interchangeably throughout this
document.
2. Conventions used in this document
A-ER: Egress Router to an Application Server, [A-ER] is
used to describe the last router that the
Application Server is attached. For 5G EC
environment, the A-ER can be the gateway router to
a (mini) Edge Computing Data Center.
Application Server: An application server is a physical or
virtual server that host the software system for
the application.
Application Server Location: Represent a cluster of servers at
one location serving the same Application. One
application may have a Layer 7 Load balancer, whose
address(es) are reachable from external IP network,
in front of a set of application servers. From IP
network perspective, this whole group of servers
are considered as the Application server at the
location.
Edge Application Server: used interchangeably with Application
Server throughout this document.
EC: Edge Computing
Edge Hosting Environment: An environment providing support
required for Edge Application Server's execution.
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NOTE: The above terminologies are the same as those
used in 3GPP TR 23.758
Edge DC: Edge Data Center, which provides the Edge Computing
Hosting Environment. It might be co-located with 5G
Base Station and not only host 5G core functions.
gNB next generation Node B
L-DN: Local Data Network
PSA: PDU Session Anchor (UPF)
SSC: Session and Service Continuity
UE: User Equipment
UPF: User Plane Function
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.
3. Proposed IPv6 Based Solution
Many Mobile operators have adopted IPv6, at least on the UE
side. With IPv6, routers within one Local Data Network can
utilize the Flow Label in IPv6 Header to avoid sending packets
from the same flow to the App Server at different locations
with the same cost, (which is a great benefit for migrating to
IPv6 network).
The solution described in this section is for the ingress
router in the new LDN to steer an application flow from a UE to
the App Server at the location that was used by the UE before
the move.
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3.1. Solution Overview
Here are some assumptions for the solution:
- Network is aware of the Sticky Services, by the Sticky
Service Identifiers, which can be ANYCAST addresses or
regular IP addresses. If an application service needs to
be sticky in the 5G Edge Computing environment, the
service ID is registered with the 5G Edge Computing
controller.
From the network perspective, a sticky service is no longer
sticky if there are no packets from the UE towards the service
ID for a specified time. The Timer should be larger than a
typical TCP session Timeout value.
Here is the overview of the proposed solution:
- Each Sticky service is assigned with a service ID, which
can be one or a group of ANYCAST addresses. It is out of
the scope of this document on how the Sticky Service ID is
generated.
- Routers that have the Sticky service servers (physical or
virtual) directly attached, a.k.a. egress routers in this
document, are configured with the ACLs that can filter out
the packets towards and from the attached App Servers.
Those egress routers usually are the Gateway routers to
the Edge computing DC,
When the Egress router filters out packets that match the
Sticky Service ID ACLs from the App Servers directly
attached, it inserts a Sticky-Dst-SubTLV [Section 3.4]in
the IPv6 extension header before forwarding the packets to
its destination (i.e. the UE).
- It is expected that application client on a UE copy the
extension header from its received IPv6 header to the
subsequent packets belonging to the same application if
the application prefers to same server instance when UE
moves.
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For UEs that cannot perform this procedure, section 4 and
5 describes the detailed steps.
- Ingress routers in the 5G LDN are also configured with the
ACLs that can filter out packets whose destination
addresses match with the Sticky Service Identifiers.
When an ingress router filters out packets based on the
Sticky Service ACL, it extracts the Sticky-Dst-SubTLV from
the packet header if the packet header has the Sticky-Dst-
SubTLV. The ingress router forwards the packets to the
egress router extracted from the Sticky-Dst-SubTLV. If the
Packet Header doesn't have the Sticky-Dst-SubTLV or fail
to match the Sticky Service ACL, the packets are forwarded
based on the least cost [5G-EC-Metrics].
3.2. Ensure one IPv6 Flow Go to the Same Location
RFC8200 specifies the IPv6 Header with the following required
fields plus multiple extension headers.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Traffic Class | Flow Label(20 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload Length | Next Header | Hop Limit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Source Address +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Destination Address +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
For most cases, it is preferable for the routers not to split
packets from one flow to the App Server located at different
Edge DCs to minimize the service glitches. The TCP based
session can be interrupted when packets from one flow are sent
to different instances.
The site-specific ingress routers can use the IPv6 header Flow
Label field to ensure the packets from one flow are forwarded
to the same Egress router to which the App Server with the
ANYCAST address is attached.
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3.3. Discover the Egress Routers for App Servers
As shown in the Figure 1 above, the App Servers at each Edge DC
are attached to one or two routers, which are usually the
Gateway routers to the Edge DC. The DC Gateway routers can
discover if there are any App Servers locally attached by
sending ARP/ND scan of the ANYCAST address. They can propagate
the addresses of the attached App Servers via BGP or IGP to
other routers. When BGP is used, the Gateway router can use the
Tunnel-Encap NLRI to inform other routers of the attached App
Servers together with the supported encapsulation tunnels
[Tunnel-Encap]. For the sake of easy description, those Gateway
routers are called Egress routers to the App Servers, or A-ER,
throughout this document.
The routers directly connected to the 5G PSA (Packet Session
Anchor) learn the addresses of the egress routers that the Edge
Servers are attach via BGP UPDATE messages advertised from
those egress routers. For the sake of easy description, the
routers that are directly connected to PSA in each 5G site are
called 5G site-specific Ingress Routers to the Local Data
Network.
The 5G site-specific ingress routers learn the egress routers
to the App Servers by the BGP UPDATE messages or the IGP
advertisement originated from those routers.
The following subsections describe how the RFC8200 specified
IPv6 extension headers, Destination Header or routing Header,
are used to achieve the goal for sticky to original App Server
location after the UE moves.
3.4. Using Destination Extension Header
A new Sticky-Dst-SubTLV is added to the IPv6 Destination
Options header. The IPv6 Destination Optino Header is specified
by RFC8200 as having a Next Header value of 60:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Header | Hdr Ext Len | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| |
| Sticky-Dst-SubTLV |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Sticky-Dst-SubTLV is specified as:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sticky-Type | Len | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Flow Label of the original flow(20 bits| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Original egress Router Identifier or Tunnel Endpoint subTLV |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Sticky-Type = 1: indicate the 32 bits identifier is used to
represent the Egress Router to an App Server.
Original egress Router Identifier: assume that all the
egress routers in the 5G Edge computing environment have
a 32-bit identifier even though they might use an IPv6
address.
Sticky-Type = 2: indicate Tunnel Endpoint SubTLV [Tunnel-
Encap] used to represent the Egress router from the original
site before the UE moves to the new site.
Here is the processing at the Egress router:
- An Egress router is configured with an ACL for filtering
out addresses of the App Servers that need sticky service.
Let's assume that each Sticky Service can be identified by
a Sticky Service ID, which can be one or a set of ANYCAST
addresses.
Note, not all applications need sticky service. Using an
ACL can greatly reduce the processing on the routers.
- When an egress router receives a packet from an attached
App Server that matches the ACL, the egress router inserts
the Destination Extension Header with the Sticky-Dst-
SubTLV to the data packet Header before forwarding the
packet back to the UE.
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Here are the steps to build the Sticky-Dst-subTLV:
- Copy the flow label from the received packet into the Flow
Label Field of the Sticky-DST-subTLV
- If the egress router has its unique 32 bits identifier,
such as the router's IPv4 loopback address, then:
o Set Sticky-Type = 1;
o Copy its own 32 bits identifier to the Original
Egress Router Identifier field;
- Else
o Set Sticky-Type = 2;
o build the Tunnel-Endpoint SubTLV per Tunnel-Encap and
insert into the field;
Here is the Expected behavior at the UE:
For edge computing services that need sticky service
while UEs roaming among multiple 5G sites, the UEs need
to extract the Destination Extension Header field from
packets received from the App Server and inserts the
extracted Destination Extension Header into the
subsequent packets belonging to the same flow.
Granted, it might take some time for Edge Computing
clients to adopt the practice of copying the IPv6
Destination Extension Header field from the received
packets to the subsequent packets belonging to the same
flow. However, once the egress routers and ingress
routers for 5G local data network support the feature,
more and more Edge Computing services would want to
utilize this special feature by adding this step.
Section 4 describes the network layer processing if UEs
do not perform the steps described here.
Here is the processing at the Ingress router:
- An Ingress router is configured with an ACL for filtering
out the applications that need sticky service.
Note, not all applications need sticky service. Using ACL
can greatly reduce the processing on the routers.
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- When an Ingress router receives a packet from the 5G PSA
that matches the ACL, the Ingress router extracts the
Sticky-Dst-SubTLV from the packet IPv6 header if the field
exists in the packet header.
- The Ingress router extracts the Flow Label and the Egress
Router Identifier from the Sticky-Dst-SubTLV.
- If the extracted Flow label matches the Flow Label in the
IPv6 header, encapsulate the packet with the tunnel type
that supported by the original egress router, using the
extracted egress router address in the destination field
of the outer header, and forward the packet. If Tunnel is
not supported, refer to Section 5 for detailed processing.
3.5. Using IPv6 Routing Extension Header
Under this option, the Sticky-Dst-SubTLV specified in Section
3.4 is inserted into Type-Specific Data field of the Routing
Extension Header of the IPv6 Header. RFC8200 describes the
Routing header as used by an IPv6 source to list one or more
intermediate nodes to be "visited" on the way to a packet's
destination. The Routing header is identified by a Next
Header value of 43 in the immediately preceding header and
has the following format:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Header | Hdr Ext Len | Routing Type | Segments Left |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| |
| type-specific data |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
All the process for Egress router, Ingress router and UE are
the same as using Destination Extension Header.
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4. Achieve Sticky Service without dependence on UE
If UEs cannot perform the steps described in the section 3.4,
LDN ingress routers have to do more.
This procedure assumes that the ingress routers are configured
with an ACL to filter out packets whose destination addresses
match with the Sticky Service Identifier.
Here are the processing steps:
- When an ingress router filters out packets that match the
Sticky Service ID ACL, ingress router registers its own
address, the source address of the filtered packets (i.e.
the UE address) and the directly connected PSA address to
the 5G EC Management System, or the 5G Network Exposure
Function (NEF).
The registration is associated with a Timer, which should
be set to larger than a typical TCP session timeout value.
When the Timer expires, the registration record is
considered no-longer active or self-removed.
The Sticky Service Registration Record should include:
o UE address
o The currently anchored PSA address
o The LDN router address that is directly connected to
the PSA
o Timer
- When a UE is re-anchoring from PSA1 to PSA2 and there is
an active sticky service record with the UE, 5GC EC
management system sends a notification to the router that
is in the sticky service record, which should be the
router directly connected to the original PSA before the
re-anchoring. The Notification includes the following
information:
o the address of the new PSA that the UE is to be
anchored, i.e. the PSA2 in the example above,
o the UE's new IP address
- Upon receiving the Notification from the 5G EC management
system, the router (i.e. the one directly connected to the
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old PSA) sends the "Sticky Service ID" (e.g. ANYCAST
Address) + Sticky-Dst-SubTLV to the router directly
connected to the new PSA.
- Upon receiving the Sticky-Dst-SubTLV, the router directly
connected to the new PSA performs the same step as
described in the Section3.4.
5. Forwarding to the desired A-ER without using Tunnel
Tunneling, i.e. encapsulating packets with an outer header that
has the desired A-ER router address in the destination field of
the outer header can guarantee to the packets to be delivered
to the egress router where the Application Server is attached.
But the tunneling has the problem of single point of failure at
the egress router. Or tunneling is not supported by the
routers.
This section describes a solution that can prioritize egress
routers for receiving packets without using tunneling.
Let's use this scenario to explain the solution:
One Application has its Application Servers attached to four
different egress routers R1, R2, R3, and R4 respectively. For
packets of a flow "A", the priority is sending to the App
Server attached to R1. When R1 or the App Server attached to
R1 fails, the packets of the flow "A" need to be forwarded to
another server of the same application attached to R2, R3, or
R4, depending on the network & utilization cost [5G-EC-
Metrics]. This desired feature is called Location Preferred
Forwarding.
Here is the procedure to achieve this type of forwarding for
ANYCAST traffic:
- Each App server is configured with multiple ANYCAST
addresses. All of them can be used as the Sticky Service
ID for the App.
- Location preferred ANYCAST addresses:
To make a specific location preferred. When failure occurs
at the preferred location, the packets are forwarded to
other locations.
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For example, for the "App.net", four different ANYCAST
addresses are allocated: L1, L2, L3, and L4:
o ANYCAST address L1 has cost lowest, say 10, when
attached to R1. L1 has higher cost, say 30, when
attached to R2, R3, and R4.
o ANYCAST L2 has the lowest cost when attached to R2.
L2 has higher cost when attached to R1, R3, R4
respectively.
o ANYCAST L3 has the lowest cost when attached to R3.
L3 has higher cost when attached to R1, R2, R4
respectively, and
o ANYCAST L4 has the lowest cost when attached to R4.
L4 has higher cost for the instance attached to R1,
R2, R3 respectively
For sticky service that needs to be sent to the App Server
attached to R1, the ingress router to which 5G PSA is directly
connected, can replace the destination address for packets
matching with the Sticky Service ACL with the L1 for steering
the packets towards R1. If R1 fails, the packets of the Flow
"App.net" can be automatically sent to R2, R3, or R4 depending
the network cost without any manual intervention.
For the procedure described in Section 3.4, the Application
egress router needs to insert L1 into the Egress-Router-ID of
the Sticky-Dst-SubTLV, so that ingress router at new 5G site
can send packets to L1, which goes to R1 if there is no failure
at R1, otherwise, packets are automatically forwarded to other
egress routers for the Application.
For initial packet, local DNS resolver can reply L1, L2, L3 or
L4 depending on where the DNS request come from to steer
packets towards the preferred site for the Edge Application
server.
6. Manageability Considerations
To be added.
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7. Security Considerations
To be added.
8. IANA Considerations
To be added.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4364] E. rosen, Y. Rekhter, "BGP/MPLS IP Virtual Private
networks (VPNs)", Feb 2006.
[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/info/rfc8174>.
[RFC8200] s. Deering R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", July 2017
9.2. Informative References
[3GPP-EdgeComputing] 3GPP TR 23.748, "3rd Generation
Partnership Project; Technical Specification Group
Services and System Aspects; Study on enhancement of
support for Edge Computing in 5G Core network (5GC)",
Release 17 work in progress, Aug 2020.
[5G-EC-Metrics] L. Dunbar, H. Song, J. Kaippallimalil, "IP
Layer Metrics for 5G Edge Computing Service", draft-
dunbar-ippm-5g-edge-compute-ip-layer-metrics-00,
work-in-progress, Oct 2020.
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[RFC5521] P. Mohapatra, E. Rosen, "The BGP Encapsulation
Subsequent Address Family Identifier (SAFI) and the
BGP Tunnel Encapsulation Attribute", April 2009.
[BGP-SDWAN-Port] L. Dunbar, H. Wang, W. Hao, "BGP Extension for
SDWAN Overlay Networks", draft-dunbar-idr-bgp-sdwan-
overlay-ext-03, work-in-progress, Nov 2018.
[SDWAN-EDGE-Discovery] L. Dunbar, S. Hares, R. Raszuk, K.
Majumdar, "BGP UPDATE for SDWAN Edge Discovery",
draft-dunbar-idr-sdwan-edge-discovery-00, work-in-
progress, July 2020.
[Tunnel-Encap] E. Rosen, et al "The BGP Tunnel Encapsulation
Attribute", draft-ietf-idr-tunnel-encaps-10, Aug
2018.
10. Acknowledgments
Acknowledgements to Donald Eastlake for their review and
contributions.
This document was prepared using 2-Word-v2.0.template.dot.
Authors' Addresses
Linda Dunbar
Futurewei
Email: ldunbar@futurewei.com
John Kaippallimalil
Futurewei
Email: john.kaippallimalil@futurewei.com
Dunbar, et al. Expires April 27, 2021 [Page 18]