



RTGWG                                                              Z. Hu
Internet-Draft                                                    Y. Zhu
Intended status: Standards Track                                   J. Hu
Expires: 19 April 2026                                             T. Pi
                                                           China Telecom
                                                         16 October 2025


  Fast Notification for tunnel-based lossless RDMA transmission in WAN
                     draft-hzh-fantel-wan-tunnel-01

Abstract

   With the rapid development of Large Language Models (LLMs), many
   emerging AI services require lossless transmission of RDMA packets
   over tunnels in Wide Area Network(WAN).  To meet the stringent
   performance demands of these services, WAN should support the real-
   time network state notification to ensure high throughput, low
   latency, and zero packet loss.  The current reactive notification
   mechanisms are limited by responsiveness, coverage, and operational
   efficiency.  Therefore, a faster and proactive notification mechanism
   is needed to enable more responsive Traffic Engineering (TE) and Load
   Balancing (LB).

   This draft describes typical scenarios for transmitting RDMA packets
   over WAN tunnels, specifies the fast notification framework to
   support key TE areas (e.g., congestion control, protection, and load
   balance), and defines the packet format for fast notification.

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 19 April 2026.






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Copyright Notice

   Copyright (c) 2025 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   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
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   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
   2.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   4
   3.  Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Scenario 1: distributed model training across DCs . . . .   4
     3.2.  Scenario 2: distributed model inference between on-premise
           DC and third-party DC . . . . . . . . . . . . . . . . . .   4
     3.3.  Scenario abstraction  . . . . . . . . . . . . . . . . . .   4
   4.  Process analyze . . . . . . . . . . . . . . . . . . . . . . .   6
     4.1.  Failure protection  . . . . . . . . . . . . . . . . . . .   6
     4.2.  Congestion control  . . . . . . . . . . . . . . . . . . .   7
     4.3.  Load balancing for network state changes  . . . . . . . .   8
   5.  Solutions . . . . . . . . . . . . . . . . . . . . . . . . . .   9
     5.1.  ICMPv6-based solution . . . . . . . . . . . . . . . . . .  10
     5.2.  UDP-based solution  . . . . . . . . . . . . . . . . . . .  11
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   8.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  12
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   In use cases such as distributed LLMs training or inference, WAN
   needs to support the tunneling of RDMA traffic between data centers
   (DCs).  RDMA is a widely used technology in high-performance
   computing and AI clusters, achieving low latency, reduced CPU
   overhead, and high network throughput.  Currently, mainstream RDMA
   protocols (e.g., IB, RoCE) are based on the Go-Back-N mechanism,



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   where a small number of packet losses can result in a dramatic
   reduction in the effective throughput.  Therefore, WAN requires a
   flow control mechanism that can timely awareness and adaptive
   response to network state changes.

   [I-D.geng-fantel-fantel-gap-analysis] points existing mechanisms for
   flow control often lack responsiveness and scalability.  ECN[RFC3168]
   is a widely deployed congestion control mechanism, which enables a
   forwarding element to notify the sender for congestion control
   without having to drop packets.  When a router detects congestion, it
   marks the packets with an ECN code-point in the IP header.  The
   receiver, upon receiving marked packets, sends a Congestion
   Notification Packet (CNP) to the sender, which then temporarily
   reduces its transmission rate until the path can accommodate higher
   traffic.  ECN still relies on end-to-end signaling, making real-time
   feedback challenging in long-distance WAN.

   To enable lossless data transmission, some drafts are proposed to
   support FAst Notification for Traffic Engineering and Load balancing
   (FANTEL).  [I-D.wh-rtgwg-adaptive-routing-arn] proposes a proactive
   notification mechanism ARN for adaptive routing, and describes the
   information carried in ARN to notify remote nodes for re-routing.
   This draft proposes a unified mechanism for congestion notifications,
   link failure notifications, and even to convey other relevant network
   events for re-routing.  [I-D.liu-rtgwg-adaptive-routing-notification]
   describes the mechanisms of delivering ARN message.  This draft gives
   three options, each of which specifies the information carried in the
   ARN message and the mechanism of sending the message to specific
   network nodes.  However, the mechanisms described in these drafts are
   not specific to tunnel-based WAN deployments.

   This document specifies the FANTEL mechanism for scenarios where
   service traffic is carried over tunnels in WAN.  It first introduces
   the typical scenarios of distributed lossless network, then specifies
   the mechanisms of FANTEL to achieve key TE areas such as congestion
   control, load balancing, and failure protection, and finally defines
   the protocol implementation.

2.  Conventions

2.1.  Abbreviations

   CNP: Congestion Notification Packet

   ECN: Explicit Congestion Notification

   FANTEL: FAst Notification for Traffic Engineering and Load balancing




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   PFC: Priority-based Flow Control

   RoCEv2: RDMA over Converged Ethernet version 2

   WAN: Wide Area Network

2.2.  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.

3.  Scenarios

3.1.  Scenario 1: distributed model training across DCs

   The growth of computing power of a single DC is limited by space and
   power supply, making it difficult to meet the fast-growing computing
   resources demands of LLMs.  Therefore, distributed model training
   across multiple DCs provides a more efficient and cost-effective
   solution to aggregate computing resources.  In this solution, a large
   volume of training parameter must be rapidly synchronized over WAN.

3.2.  Scenario 2: distributed model inference between on-premise DC and
      third-party DC

   Some customers deploy LLMs by building on-premises AI facilities, but
   as inference concurrency increases, scaling out these facilities
   requires significant investment.  To address this, distributed model
   inference between customer on-premise DC and third-party DC provides
   a more agile and cost-effective solution to scale computing resource
   elasticly.  In this solution, a large volume of inference parameter
   must be rapidly synchronized over WAN.

3.3.  Scenario abstraction

   In the above scenarios, parameter data between DCs need to be
   synchronized using RDMA protocol.  Therefore, operators prefer to
   carry such RDMA traffic over tunnels across the WAN, ensuring
   efficient and lossless transmission.  The framework for lossless RDMA
   data transmission over WAN tunnels is as follows:








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                   +--------------------------------------------------+
                   |                       DC1                        |
                   |                                                  |
                   | +-----------+  +-----------+       +-----------+ |
                   | |AI server 1|  |AI server 2|  ...  |AI server n| |
                   | +-----------+  +-----------+       +-----------+ |
                   +------------------------+-------------------------+
                                            |
                   +------------------------+-------------------------+
                   |   WAN            +-----+----+                    |
                   |           +------+ingress PE+------+             |
                   |           |      +----------+      |             |
                   |           |                        |             |
                   |        +--+---+                 +--+---+         |
                   |        |  R1  +                 +  R2  |         |
                   |        +--+---+\               /+--+---+         |
                   |           |     \             /    |             |
                   |           |      \+---------+/     |             |
                   |           |       +   R5    +      |             |
                   |           |      /+---------+\     |             |
                   |           |     /             \    |             |
                   |        +--+---+/               \+--+---+         |
                   |        |  R3  +                 +  R4  |         |
                   |        +--+---+                 +--+---+         |
                   |           |                        |             |
                   |           |       +---------+      |             |
                   |           +-------+egress PE+------+             |
                   |                   +----+----+                    |
                   +------------------------+-------------------------+
                                            |
                   +------------------------+-------------------------+
                   | +-----------+  +-----------+       +-----------+ |
                   | |AI server 1|  |AI server 2|  ...  |AI server m| |
                   | +-----------+  +-----------+       +-----------+ |
                   |                                                  |
                   |                       DC2                        |
                   +--------------------------------------------------+
                               Figure 1: Network diagram

   *  The AI servers in DC1 sends RDMA traffic to WAN's ingress PE.

   *  At the WAN's ingress PE, the RDMA traffic is encapsulated
      according to the tunnel protocol and forwarded across WAN to
      egress PE.

   *  The WAN's P node(R1-R5) transits the payload from ingress PE to
      egress PE via tunnels.




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   *  At the WAN's egress PE, the payload are decapsulated to RDMA
      packets and transmitted to the AI servers in DC2.

4.  Process analyze

   Tunneling technologies include various protocols, such as GRE, VXLAN,
   MPLS, and SRv6.  AI traffic is characterized by high volume and high
   burstiness, making it prone to cause network congestion.  Operators
   must adopt tunneling technologies that provide strict TE guarantees
   (process analyze herein is also based on the assumption of a strict
   TE environment).  When transmittig RDMA traffic over tunnels, WAN
   should support FANTEL capability to realize rapid response to network
   conditions.  Specifically, WAN devices should support fast
   notification mechanism to imporve three key TE scenarios: failure
   protection, flow control, and load balancing.

4.1.  Failure protection

   For large-scale and dynamic networks, protection mechanisms need to
   ensure service continuity in case of failures.  According to
   [I-D.geng-fantel-fantel-gap-analysis], existing failure handling
   methods, such as BFD and FRR, lack flexibility and responsiveness in
   complex typologies.  Therefore, WAN should support fast notification
   for failures, allowing near-instantaneous and dynamic protection
   responses, minimizing failure impact.

   Upon network failure, the ingress PE should immediately adapt its
   forwarding policy to steer traffic away from faulty links or nodes.
   Therefore, the fast-notification-based failure protection process is
   as follows:

           notification
         +--------------+
         |              |
         |          +---+--+    +------+
         |          |  R1  +--x-+  R2  |
         |         /+------+  ^ +------+\
         |        /           |          \
         v       /         failure        \
   +----------+ /                          \ +---------+
   |          |/                            \|         |
   |ingress PE|\                            /|egress PE|
   |          | \                          / |         |
   +----------+  \                        /  +---------+
                  \ +------+    +------+ /
                   \|  R3  +----+  R4  |/
                    +------+    +------+
                           Figure 2: Failure protection procession



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   *  When a P node detects a local link/node failure, it collects
      failure information about the affected link or flow.

   *  The P node sends notification to ingress PE with failure
      information (In addition to the identity of the failed link or
      node, the notification must also include information about the
      affected traffic).

   *  Ingress PE receives the notification and reroutes the traffic
      based on its content to exclude the failed link or node: *If
      backup path is available, ingress PE should switch the service
      traffic to the backup path.  *If multiple feasible paths exist,
      ingress PE should updates its load-balancing policy to utilize all
      available paths.  *If no feasible path is available, ingress PE
      should send a corresponding notification to the sender and
      controller.

4.2.  Congestion control

   RDMA traffic is bursty and highly sensitive to packet loss, and WAN
   require proactive congestion control mechanisms.  [RFC6040] redefines
   how the explicit congestion notification (ECN) field of the IP header
   should be constructed on entry to and exit from any IP-in-IP tunnel,
   in order to achieve ECN-based congestion control across WANs between
   DCs.  However, [I-D.geng-fantel-fantel-gap-analysis] analysis that
   ECN/TCP methods still relies on end-to-end signaling and lacks
   precise real-time feedback.

   Currently, PFC is widely used in data centers to prevent data loss
   due to congestion.  PFC uses a step-by-step back-pressure mechanism
   to control the upstream to stop or continue transmitting traffic.
   PFC achieves link-layer priority-based traffic control, but still
   faces problems such as queue head blocking and deadlock due to coarse
   control granularity.

   When network congestion occurs, the ingress PE should immediately
   adapt its forwarding policy to reduce the traffic sent to congested
   nodes.  Meanwhile, the upstream nodes to the congested node should
   reduce the transmission rate of corresponding traffic to minimize the
   likelihood of packet loss.  Therefore, the fast-notification-based
   congestion control process is as follows:










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                  notification
         +---------------------------+
         |                           |
         |             notification  |
         |             +----------+  |
         |             |          |  |
         |             v          |  |
         |          +------+    +-+--+-+
         |          |  R1  +----+  R2  |
         |         /+------+    +------+\
         |        /                      x<---congestion
         v       /                        \
   +----------+ /                          \ +---------+
   |          |/                            \|         |
   |ingress PE|\                            /|egress PE|
   |          | \                          / |         |
   +----------+  \                        /  +---------+
                  \ +------+    +------+ /
                   \|  R3  +----+  R4  |/
                    +------+    +------+
                           Figure 3: Congestion control procession

   *  when a P node detects congestion, it collects congestion
      information about the congested link or flow.

   *  The P node sends notification to ingress PE and upstream with
      congestion information.

   *  The upstream P node receives the notification and reduce the
      transmission rate of corresponding traffic.

   *  Ingress PE receives the notification and reroutes the traffic
      based on its content to exclude the congestion link: *If backup
      path is available, ingress PE should switch the service traffic to
      the backup path.  *If multiple feasible paths exist, ingress PE
      should updates its load-balancing policy to utilize all available
      paths.  *If no feasible path is available, ingress PE should
      reduce the transmission rate of corresponding traffic, and send
      notification to sender and controller.

4.3.  Load balancing for network state changes

   Devices and links in WAN often carry multiple services
   simultaneously.  In addition to failure and congestion, dynamic load
   balancing based on network state changes can effectively improve
   network resource utilization.





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   When significant changes occur in the network state, the ingress PE
   should dynamically adjust its forwarding strategy to maximize network
   resource utilization.  Therefore, the fast-notification-based load
   balancing process is as follows:

        notification
      +--------------+
      |              |
      |          +---+--+    +------+
      |          |  R1  +----+  R2  |
      |         /+------+  ^ +------+\
      |        /           |          \
      v       /     link utilization   \
+----------+ /           change         \ +---------+
|          |/                            \|         |
|ingress PE|\                            /| gress PE|
|          | \          node load change/ |         |
+----------+  \                 |      /  +---------+
      ^        \                v     /
      |         \+------+    +------+/
      |          |  R3  +----+  R4  |
      |          +------+    +---+--+
      |                          |
      +--------------------------+
              notification
                        Figure 4: Load balancing for network state changes

   *  When a node detects the network state change, it collects the
      network state change information, such as link utilization, queue
      buildup.

   *  The node sends fast notification to the ingress PE with
      information about the network state change.

   *  Ingress PE receives the fast notification and updates its load-
      balancing policy to maximize the utilization of network resources.

5.  Solutions

   Based on the framework analysis of fast notification in key TE areas,
   a unified protocol implementation for fast notification should be
   established, with explicit forwarding procedures to realize tunnel-
   based lossless transmission of RDMA packets in WAN.








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5.1.  ICMPv6-based solution

   The source quench mechanism has been deprecated in ICMPv6 because
   TCP's built-in congestion avoidance algorithms are more efficient,
   and source quench may interfere with their normal operation.
   However, when transmitting RDMA data over WAN tunnels, the source
   quench notification is confined within the WAN domain (this message
   is used by WAN devices such as Ingress PE or transit node for traffic
   engineering) and does not affect transport layer congestion control.

   This document specifies a new ICMP message to realize rapid
   notification in key traffic engineering areas including failure
   protection, congestion control, and load balancing.  The message
   format is defined as follows:

             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    |     CODE      |         Checksum              |
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |                                                               |
            |                                                               |
            |               Message Body(Variable length)                   |
            |                                                               |
            |                                                               |
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                        Figure 5: new ICMPv6 message for fast notification

   *TYPE:8-bit identifier for the purposes of notification, When it is
   set to 1, it indicates the fast notification for failure protection;
   When it is set to 2, it indicates the fast notification for failure
   elimination; When it is set to 3, it indicates the fast notification
   for congestion control; When it is set to 4, it indicates the fast
   notification for congestion elimination; When it is set to 5, it
   indicates the fast notification for load balancing.  Other bits are
   not defined.

   *CODE: This field is an 8-bit bitmap that specifies which parameters
   are included in the message body of the packet.

   *Checksum: Used for error-checking the packet.

   *Message Body: It carries notification information specific to each
   areas: for failure protection, it includes path, five-tuple of flow,
   and failure cause; for congestion control, it contains path and
   buffer status; for load balancing, it comprises link utilization and
   device load.  This field format need to be designed with
   extensibility, while subsequent refinements and specific packet
   forwarding mechanisms(TBD).



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5.2.  UDP-based solution

   This document specifies a new UDP message to realize rapid
   notification in key traffic engineering areas including failure
   protection, congestion control, and load balancing.  The message
   format is defined as follows:


            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
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |        UDP source port        |   UDP destination port(TBD)   |
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |          UDP length           |        UDP Checksum           |
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |Version|     Type      |       Code    |         Rvsd          |
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |                                                               |
            |                                                               |
            |               Message Body(Variable length)                   |
            |                                                               |
            |                                                               |
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                        Figure 6: new UDP message for fast notification

   Version: This field indicates the version number.  The default value
   is 0.

   *TYPE:8-bit identifier for the purposes of notification, When it is
   set to 1, it indicates the fast notification for failure protection;
   When it is set to 2, it indicates the fast notification for failure
   elimination; When it is set to 3, it indicates the fast notification
   for congestion control; When it is set to 4, it indicates the fast
   notification for congestion elimination; When it is set to 5, it
   indicates the fast notification for load balancing.  Other bits are
   not defined.

   *CODE: This field is an 8-bit bitmap that specifies which parameters
   are included in the message body of the packet.

   Rvsd:Reserved

   *Message Body: It carries notification information specific to each
   areas: for failure protection, it includes path, five-tuple of flow,
   and failure cause; for congestion control, it contains path and
   buffer status; for load balancing, it comprises link utilization and
   device load.  This field format need to be designed with
   extensibility, while subsequent refinements and specific packet
   forwarding mechanisms(TBD).



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6.  Security Considerations

   TBD

7.  IANA Considerations

   TBD

8.  Acknowledgments

   TBD

9.  References

9.1.  Normative References

   [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>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [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>.

9.2.  Informative References

   [RFC3168]  Ramakrishnan, K., Floyd, S., and D. Black, "The Addition
              of Explicit Congestion Notification (ECN) to IP",
              RFC 3168, DOI 10.17487/RFC3168, September 2001,
              <https://www.rfc-editor.org/info/rfc3168>.

   [RFC6040]  Briscoe, B., "Tunnelling of Explicit Congestion
              Notification", RFC 6040, DOI 10.17487/RFC6040, November
              2010, <https://www.rfc-editor.org/info/rfc6040>.

   [RFC7514]  Luckie, M., "Really Explicit Congestion Notification
              (RECN)", RFC 7514, DOI 10.17487/RFC7514, April 2015,
              <https://www.rfc-editor.org/info/rfc7514>.








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   [I-D.wh-rtgwg-adaptive-routing-arn]
              Wang, H., Huang, H., Geng, X., Xu, X., and Y. Xia,
              "Adaptive Routing Notification", Work in Progress,
              Internet-Draft, draft-wh-rtgwg-adaptive-routing-arn-03, 13
              September 2024, <https://datatracker.ietf.org/doc/html/
              draft-wh-rtgwg-adaptive-routing-arn-03>.

   [I-D.liu-rtgwg-adaptive-routing-notification]
              Liu, Y., lihesong, and W. Duan, "Adaptive Routing
              Notification for Load-balancing", Work in Progress,
              Internet-Draft, draft-liu-rtgwg-adaptive-routing-
              notification-02, 12 June 2025,
              <https://datatracker.ietf.org/doc/html/draft-liu-rtgwg-
              adaptive-routing-notification-02>.

   [I-D.xiao-rtgwg-rocev2-fast-cnp]
              Min, X. and lihesong, "Fast Congestion Notification Packet
              (CNP) in RoCEv2 Networks", Work in Progress, Internet-
              Draft, draft-xiao-rtgwg-rocev2-fast-cnp-03, 9 June 2025,
              <https://datatracker.ietf.org/doc/html/draft-xiao-rtgwg-
              rocev2-fast-cnp-03>.

   [I-D.geng-fantel-fantel-gap-analysis]
              Geng, X., Huo, P., Cheng, W., Li, D., Zhu, Y., and H.
              Zhengxin, "Gap Analysis of Fast Notification for Traffic
              Engineering and Load Balancing", Work in Progress,
              Internet-Draft, draft-geng-fantel-fantel-gap-analysis-01,
              7 July 2025, <https://datatracker.ietf.org/doc/html/draft-
              geng-fantel-fantel-gap-analysis-01>.

Authors' Addresses

   Zehua Hu
   China Telecom
   Guangzhou
   China
   Email: huzh2@chinatelecom.cn


   Yongqing Zhu
   China Telecom
   Guangzhou
   China
   Email: zhuyq8@chinatelecom.cn







Hu, et al.                Expires 19 April 2026                [Page 13]

Internet-Draft  Fast Notification for tunnel-based lossl    October 2025


   Jiayuan Hu
   China Telecom
   Guangzhou
   China
   Email: hujy5@chinatelecom.cn


   Tanxin Pi
   China Telecom
   Guangzhou
   China
   Email: pitx1@chinatelecom.cn







































Hu, et al.                Expires 19 April 2026                [Page 14]
