Routing Considerations in Agentic Network
draft-du-catalist-routing-considerations-00

Network Working Group                                              Z. Du
Internet-Draft                                              China Mobile
Intended status: Informational                              2 March 2026
Expires: 3 September 2026

               Routing Considerations in Agentic Network
              draft-du-catalist-routing-considerations-00

Abstract

   As the development of the AI technology, an AI Agent would be able to
   do some tasks as an assistant to human beings.  During the task
   process, the Agent may need to connect to other Agents with different
   skills relative to the task.  The Agent to Agent communication is a
   new kind of traffic for Internet, and some new requirements for
   networking are proposed.  This document describes some routing
   considerations in the agentic network, especially for the cross-
   domain scenarios, in which the agentic network works as an overlay
   network above the IP network.

Requirements Language

   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 RFC 2119 [RFC2119].

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Copyright Notice

   Copyright (c) 2026 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Intra-domain and Inter-domain . . . . . . . . . . . . . . . .   3
   3.  Peer-to-peer Connection and Message System  . . . . . . . . .   3
     3.1.  Direct-Connected Mode . . . . . . . . . . . . . . . . . .   4
     3.2.  One Agent Communication Server Mode . . . . . . . . . . .   4
     3.3.  AGW Network . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Routing Considerations for AGW Network  . . . . . . . . . . .   5
     4.1.  Forwarding Based on Agent ID  . . . . . . . . . . . . . .   5
     4.2.  Forwarding Based on AGW ID  . . . . . . . . . . . . . . .   6
     4.3.  Forwarding Based on Channel ID  . . . . . . . . . . . . .   6
     4.4.  Forwarding Based on Skill . . . . . . . . . . . . . . . .   6
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   In [I-D.rosenberg-ai-protocols], some use cases and requirements for
   AI Agent protocols are introduced.  Meanwhile, a framework is
   described for the agent communications, and it includes the
   communications between AI agent and User, AI agent and API, AI agent
   and AI agent.  In this document, we mainly focus on the Agent to
   Agent communication scenarios.

   In the agentic network, it is assumed that many Agents exist, and
   they need to cooperate to complete tasks.  The AI Agents in the same
   task group need to form a virtual network to communicate with each
   other, and after the task completing, the communication group may be
   released.

   The main purpose of this document is to describe some routing
   considerations in the agentic network.  Other issues, such as the
   discovery and authentication of the target Agents, are out of scope.

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2.  Intra-domain and Inter-domain

   The Agent commutation nowadays mainly happens in the intra-domain
   scenarios, in which many problems would be simpler.  As introduced in
   the [I-D.zyyhl-agent-networks-framework], the scenarios about the
   single trusted domain are analyzed firstly, and cross-domains are
   suggested to be considered in future.  In that trusted domain, a
   Registration Server is responsible for establishing the trust
   relationship, and a Communication Server is responsible for
   communications between the Agents.  For these intra-domain cases,
   most of the agents should be well known to the administrator, or to
   the Registration Server.

   When the scenarios are extended into the Internet level, where cross-
   domains become unavoidable, things become more complicated.  As
   mentioned in the [I-D.rosenberg-ai-protocols] , an Agent should not
   trust another Agent only because it is one of the results provided by
   a search engine on the Internet, and a high level of trust is
   required for one AI agent to talk to another one in the inter-domain
   cases.  Meanwhile, in the cross-domain scenarios, if different
   domains could follow the same standardized realization, the
   communication would be much easier.

3.  Peer-to-peer Connection and Message System

   There are many different tasks and different scenarios for Agent
   communications.  In this section, we introduce three kinds of
   connection modes as follows.

   1.  Direct-connected mode: AI agents directly send and receive
       messages without the need for intermediate nodes for processing.

   2.  Indirect Communication by using one Agent Communication Server:
       It often appears in a single domain scenario.  Communication
       between AI agents requires processing/relaying by a Agent
       Communication Server, and the AI agent must be aware of and
       interact with the Agent Communication Server.

   3.  Indirect Communication by using the AGW network: It often happens
       in cross-domain scenarios.  An AI agent firstly connects a
       Communication Server or called an Agent Gateway (AGW), and then
       communicates with other Agents by using the AGW network.  The
       Agents in the task group may attach to different Agent Gateways,
       so that more hops are involved.

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   The second case can also work for cross-domain scenarios, if we
   assume that a super Agent Communication Server exist.  However, the
   distributed solution mentioned as the third one will have benefits
   such as the path length and the scalability.

3.1.  Direct-Connected Mode

   If the Agent communication only happens between two Agents, the peer-
   to-peer mode would be the most straightforward approach.  We can also
   call it a direct-connected mode.

   If more Agents are involved in the communication for the task, this
   direct-connected mode can also work.  However, the leader of the task
   group needs to be responsible for all the transmitting of the
   messages.

   Normally, the leader is the Agent that receives the task, and finds
   partners to complete the task.  Thus, in this case, the leader
   initiates the task group, and is responsible for the interaction of
   the Agents, while other Agents only need to have a connection to the
   leader.

3.2.  One Agent Communication Server Mode

   As mentioned in [I-D.mpsb-agntcy-messaging], the Advanced Message
   Queuing Protocol (AMQP) is often used for enterprise messaging
   systems.  With the message system, asynchronous processing is
   enabled, and reliable message delivery for distributed transactions
   can be guaranteed.  Additionally, it supports flexible routing and
   easy integration of new components, enhancing overall architecture
   resilience and adaptability.

   Therefore, if many Agents exist in the enterprise, they can
   communicate by using a message queue system, which can simplify the
   communication of Agents because many functions about communication
   can be done outside of the Agent.

   In this case, an Agent only needs to have a connection to the Agent
   Communication Server.  We can realize the message queue system in
   this Agent Communication Server.

3.3.  AGW Network

   For cross-domain scenarios, multiple Agent Communication Servers
   could exist.  As it is for inter-domain, we can also consider that
   Agent Communication Server works as the Agent Gateways.

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   It is assumed that each domain has an Agent Gateway, and the Agent
   Gateways have already been connected by some means.  Thus, the A2A
   connection is composed of three parts, i.e., from the source Agent to
   the AGW A1 that it attaches to, from AGW A1 to another AGW A2, and
   from AGW A2 to the target Agent.

   The structure is described in [I-D.mpsb-agntcy-slim], in which the
   Agent Gateway is considered as a Message Node or a Routing Node.

4.  Routing Considerations for AGW Network

   After connecting the Agent Gateways, we establish an overlay network
   above the IP network for cross-domain scenarios of the Agent
   communication.  Based on this overlay network, Agents can dynamically
   establish virtual groups on demand.

   The AGWs should be able to support flexible forwarding mechanisms.
   Four requirements are listed as follows.

   1.  Forwarding based on Agent ID: AI agents should have a structured
       ID that can be discovered and addressed.

   2.  Forwarding based on AGW ID: The forwarding table of AGW IDs
       should be per-configured in the AGW.

   3.  Forwarding based on Channel ID: The channel ID is related to the
       virtual group.  It supports multicast in the task group.

   4.  Forwarding based on Skill: It happens in the discovery stage.
       When many agents can provide the same skill, they can advertise
       the same skill ID into the AGW network.

   In the last case, the registration/discovery system can also give the
   suggestion about which Agent should be connected.  However, anycast
   on the AGW network can also be a potential solution for some
   scenarios.  It is similar to the relationship between the GSLB
   (Global Server Load Balance) technology based on DNS and the anycast
   technology based on BGP.

4.1.  Forwarding Based on Agent ID

   The number of Agents in the agentic network could be very large.
   However, the Agent IDs normally can not be aggregated as IP addresses
   do.  Thus, we do not need the AGW to have a complete forwarding table
   for all the Agent ID in advance.

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   If a target Agent ID is received, and an AGW does not know how to
   route the traffic.  It can query the registration/discovery system
   for that ID.

   Meanwhile, for the intra-domain traffic, the AGW could support the
   forwarding of the traffic more easily.  The AGW should be aware of
   the Agents that attach to it, and maintain an attached Agent table.

4.2.  Forwarding Based on AGW ID

   As talked before, the interconnection of the Agent Gateway is the
   per-condition of the AGW network.  Some information exchanges should
   be supported among the AGWs.

   If an AGW can not recognize a specific Agent ID, it should perform a
   discovery procedure, and obtain the target AGW ID that the Agent
   attaches to.  Next, the AGW forwards the message to the target AGW,
   and the target AGW should be aware of the location of the Agent.

4.3.  Forwarding Based on Channel ID

   As the communication happens among a task group, and the AGW network
   would support many virtual networks, each for a task group, AGW
   should support forwarding based on the channel ID.

   AGWs that are involved in the traffic of a task group should maintain
   a forwarding table of the channel ID corresponding to the task group.

   Meanwhile, the AGW should be aware of the local-connected Agents that
   have subscribed the channel.

4.4.  Forwarding Based on Skill

   In the agentic network, many Agents own the same skill, and they can
   advertise the same target address into the agentic network.  The
   selection method may related to the network distance, the predicted
   service experience, etc.

5.  IANA Considerations

   TBD.

6.  Security Considerations

   TBD.

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7.  Acknowledgements

   TBD.

8.  References

8.1.  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>.

8.2.  Informative References

   [I-D.mpsb-agntcy-messaging]
              Muscariello, L., Papalini, M., Sardara, M., and S. Betts,
              "An Overview of Messaging Systems and Their Applicability
              to Agentic AI", Work in Progress, Internet-Draft, draft-
              mpsb-agntcy-messaging-01, 24 February 2026,
              <https://datatracker.ietf.org/doc/html/draft-mpsb-agntcy-
              messaging-01>.

   [I-D.mpsb-agntcy-slim]
              Muscariello, L., Papalini, M., Sardara, M., and S. Betts,
              "Secure Low-Latency Interactive Messaging (SLIM)", Work in
              Progress, Internet-Draft, draft-mpsb-agntcy-slim-01, 24
              February 2026, <https://datatracker.ietf.org/doc/html/
              draft-mpsb-agntcy-slim-01>.

   [I-D.rosenberg-ai-protocols]
              Rosenberg, J. and C. F. Jennings, "Framework, Use Cases
              and Requirements for AI Agent Protocols", Work in
              Progress, Internet-Draft, draft-rosenberg-ai-protocols-00,
              5 May 2025, <https://datatracker.ietf.org/doc/html/draft-
              rosenberg-ai-protocols-00>.

   [I-D.zyyhl-agent-networks-framework]
              Zhouye, Yao, K., Yu, M., Han, M., and C. Li, "Framework
              for AI Agent Networks", Work in Progress, Internet-Draft,
              draft-zyyhl-agent-networks-framework-01, 20 October 2025,
              <https://datatracker.ietf.org/doc/html/draft-zyyhl-agent-
              networks-framework-01>.

Author's Address

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   Zongpeng Du
   China Mobile
   No.32 XuanWuMen West Street
   Beijing
   100053
   China
   Email: duzongpeng@foxmail.com

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