Global Routing Operations                                        Y. Liu
Internet Draft                                             China Mobile
Intended status: Standards Track                                 C. Lin
Expires: August 19, 2025                           New H3C Technologies
                                                                T. Graf
                                                               Swisscom
                                                             P. Lucente
                                                                    NTT
                                                      February 19, 2025


                      Using BMP over QUIC connection
                      draft-liu-grow-bmp-over-quic-02


Abstract

   The BGP Monitoring Protocol (BMP) provides a convenient interface
   for obtaining route views by monitoring BGP sessions. BMP operates
   over TCP and is unidirectional (from client to server). QUIC
   provides multiple simultaneous streams to carry data in one
   direction, enabling much better efficiency and performance for both
   peers, in particular unidirectional streams can provide reverse data
   protection for the sender. QUIC also provides shorter handshake and
   includes TLS. This document describes how to use BMP over the QUIC
   transport protocol, named BMPoQUIC.

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
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   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
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   This Internet-Draft will expire on August 19, 2025.

Copyright Notice

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



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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with
   respect to this document. Code Components extracted from this
   document must include Simplified BSD License text as described in
   Section 4.e of the Trust Legal Provisions and are provided without
   warranty as described in the Simplified BSD License.

Table of Contents


   1. Introduction...................................................2
   2. Terminology and Definitions....................................3
   3. Connection Management..........................................4
      3.1. Connection Establishment..................................4
      3.2. Connection Termination....................................4
         3.2.1. QUIC Connection Termination Process..................4
         3.2.2. BMPoQUIC Considerations for Connection Termination...4
   4. Stream mapping and usage.......................................4
      4.1. Multi-stream Selection....................................5
         4.1.1. Peer Stream..........................................5
         4.1.2. Per-AFI/SAFI Stream without Control Stream...........6
         4.1.3. Per-AFI/SAFI Stream with Control Stream..............7
   5. Endpoint Authentication........................................8
   6. Operational Considerations.....................................8
   7. IANA Considerations............................................9
   8. Security Considerations........................................9
   9. References.....................................................9
      9.1. Normative References......................................9
      9.2. Informative References...................................10
   Authors' Addresses...............................................11



1. Introduction

   The BGP Monitoring Protocol (BMP) [RFC7854] defines a standard
   mechanisms for obtaining route views by monitoring BGP sessions. BMP
   operation uses TCP as its transport protocol to provide reliable
   communication. BMP establishes connection relationships between
   monitored router and monitoring station using a TCP session.

   In BMP message communication, in order to simplify the
   implementation, only the monitored router reports messages to the
   monitoring station, and the station does not send messages to the
   router [RFC7854]. In other words, the BMP communication is actually

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   unidirectional (from router to station). As a consequence, the
   direction from the monitoring station to the monitored router may be
   used as an interface for malicious attacks on the router. As BMP
   supports more and more types of routes to be reported, the number of
   reported BMP messages is also increasing, which also brings huge
   challenges to TCP data transmission pressure.

   QUIC [RFC9000] is a UDP-based multiplexed and secure transport
   protocol that provides connection-oriented and stateful interaction
   between a client and server. It can provide low latency and
   encrypted transport with resilient connections.

   QUIC uses multiple simultaneous streams to carry data in one
   direction. Each stream is a separate unidirectional or bidirectional
   channel consisting of an ordered stream of bytes. In Addition, each
   stream has its own flow control, which limit bytes sent on a stream,
   together with flow control of the connection. Among them, the
   unidirectional stream is very consistent with the message
   transmission mechanism of BMP.

   Therefore, QUIC is a proper transport protocol for the message
   transmission mechanism of BMP. This document specifies how to use
   QUIC as the secure transport protocol for BMP.

2. Terminology and Definitions

   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].

   In this document, the terms "client" and "server" are used to refer
   to the two ends of the QUIC connection. The client actively
   initiates the QUIC connection. The terms "monitored router" and
   "monitoring station" are used to refer to the two ends of the BMP
   session. The router sends BMP messages to the station, but the
   station does not respond to the router.

   *  Client: The endpoint that initiates a QUIC connection, the BMP
   monitored router.

   *  Server: The endpoint that accepts a QUIC connection, the BMP
   monitoring station.







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3. Connection Management

3.1. Connection Establishment

   QUIC connection establishment is described in [RFC9000]. During
   establishing connection, BMPoQUIC support is indicated by selecting
   the Application-Layer Protocol Negotiation (ALPN) [RFC7301] token as
   listed in the IANA sectionSection 7 in the TLS handshake.

   The monitored router MUST also act as the client meanwhile the
   monitoring station must also act as the server.

   The monitored router should be the initiator of the QUIC connection
   to the monitoring station meanwhile the monitoring station acts as a
   connection acceptor.

3.2. Connection Termination

3.2.1. QUIC Connection Termination Process

   The typical QUIC connection termination process is described in
   [RFC9000].

3.2.2. BMPoQUIC Considerations for Connection Termination

   When a BMP session is implemented based on a QUIC connection, the
   idle timeout should be disabled or the QUIC max_idle_timeout should
   be set appropriately in order to keep the QUIC connection persistent
   even if the BMP session is idle.

   When a BMP monitoring station receives a termination message, it
   will graceful close the BMP session. The station SHOULD close the
   associated QUIC connection.

   When a BMP monitored router is detecting the interruption of the
   QUIC connection, it SHOULD send a termination message to the BMP
   monitoring station.

4. Stream mapping and usage

   There are seven kinds of BMP main message sent from monitored router
   to monitoring station, namely route monitoring message, statistics
   report message, peer down notification message, peer up notification
   message, initiation message, termination message and route mirroring
   message [RFC7854]. The seven kinds of BMP messages need to be mapped
   into QUIC streams.



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   QUIC [RFC9000] is a UDP-based multiplexed and secure transport
   protocol that provides connection-oriented and stateful interaction
   between a client and server. It can provide low latency and
   encrypted transport with resilient connections.

   QUIC uses Stream ID to identify the stream. The least significant
   bit (0x1) of the stream ID identifies the initiator of the stream.
   The second least significant bit (0x2) of the stream ID
   distinguishes between bidirectional streams (with the bit set to 0)
   and unidirectional streams.

   No BMP message is ever sent from the monitoring station to the
   monitored router. The monitored router MAY take steps to prevent the
   monitoring station from sending data or it MAY silently discard any
   data sent by the monitoring station. So BMP messages from monitored
   router SHOULD be mapped into unidirectional stream whose stream type
   is 0x2 according to the above.

4.1. Multi-stream Selection

4.1.1. Peer Stream

   When a router has many peers and a large number of routes, if the
   related BMP messages are reported through an independent stream, the
   communication pressure of this stream will be very large and the
   efficiency will be very low. In order to reduce the communication
   pressure and improve the communication efficiency, multiple streams
   can be allocated according to the number of peers of the router, and
   each stream is used to transmit the BMP message of the specified
   peers, as shown in Figure 1. The number of streams can be configured
   as needed.

   +------------+                       +--------------+
   |   Peer 1   |                       |              |
   |            |---------------------->|   Stream 1   |
   |   Peer 2   |                       |              |
   +------------+                       +--------------+
         ~                                      ~
         ~                                      ~
   +------------+                       +--------------+
   |   Peer x   |                       |              |
   |            |---------------------->|   Stream n   |
   |   Peer y   |                       |              |
   +------------+                       +--------------+
   Figure 1: Peer Stream Structure

   When multiple peer streams are used to transmit BMP messages, each
   stream needs to transmit peer-insensitive BMP messages (that is, BMP

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   messages that do not carry the per-peer header format) to ensure the
   order of BMP messages. Peer-insensitive BMP messages include
   Initiation Message and Termination Message [RFC7854].

4.1.2. Per-AFI/SAFI Stream without Control Stream

   If multiple peer streams are used, each stream may carry different
   type (AFI/SAFI) routes from router, which may make the information
   seem a bit messy. So unidirectional QUIC streams can be created for
   Per-AFI/SAFI to carry the routes of the specific AFI/SAFI, as shown
   in the figure below.

   +----------------+                       +--------------+
   |   AFI/SAFI 1   |---------------------->|   Stream 1   |
   +----------------+                       +--------------+
           ~                                       ~
           ~                                       ~
   +----------------+                       +--------------+
   |   AFI/SAFI n   |---------------------->|   Stream n   |
   +----------------+                       +--------------+
   Figure 2: Per AFI/SAFI Stream Structure

   When per-AFI/SAFI streams are used to transmit BMP messages, it is
   necessary to distinguish which BMP messages can be categorized by
   per-AFI/SAFI and Determine how to send BMP messages for non-per-
   AFI/SAFI.

   * For Initiation Message and Termination Message, they are all non-
   per-AFI/SAFI message, but they are messages necessary for session
   connection, so each Per-AFI/SAFI stream needs to send them.

   * For Route Monitoring message, it is per-AFI/SAFI route message,
   and it can be carried over corresponding AFI/SAFI stream.

   * For Route Mirroring message, if the message includes BGP PDU and
   the BGP PDU can distinguish AFI/SAFI information, it could be
   carried over corresponding AFI/SAFI stream. If not, it should be
   carried over any one of AFI/SAFI streams.

   * For Statistics Report message, if the stat type is based on per-
   AFI/SAFI, it could be carried over corresponding AFI/SAFI stream. If
   not, it should be carried over any one of AFI/SAFI streams.

   * For Peer up Notification message, it could include open message of
   one AFI/SAFI, and it should be carried over corresponding AFI/SAFI
   stream.



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   * For Peer down Notification message, as it does not include
   AFI/SAFI information, it should be carried over all corresponding
   AFI/SAFI streams which carry Peer up Notification message.

   If BGP still uses TCP as the transport protocol, the Per AFI/SAFI
   Stream structure can be used selectively. If BGP uses QUIC as the
   transport protocol [I-D.draft-retana-idr-bgp-quic], the Per AFI/SAFI
   Stream structure MUST be used because of the implementation that
   per-AFI/SAFI streams (function channels) are used to carry routing
   information in one BGP over QUIC (BoQ) connection.

4.1.3. Per-AFI/SAFI Stream with Control Stream

   Like the design of BGP over QUIC (BoQ) [I-D.draft-retana-idr-bgp-
   quic], the per-peer or per-AFI/SAFI streams (function channels) and
   the associated control mechanism (control channel) for the session
   are called "BMP channels". In one BMP over QUIC (BMPoQUIC)
   connection, one control channel and one or more function channels
   are used to carry BMP information, as shown in the figure below.

   +------------------------+               +--------------+
   |    Control Channel     |-------------->|   Stream 1   |
   +------------------------+               +--------------+
   +------------------------+               +--------------+
   |   Function Channel 1   |-------------->|   Stream 2   |
   +------------------------+               +--------------+
           ~                                       ~
           ~                                       ~
   +------------------------+               +--------------+
   |   Function Channel n   |-------------->|   Stream n   |
   +------------------------+               +--------------+
   Figure 3: BMP Channel Structure

   On a BMPoQUIC connection, the BMPoQUIC client first establishes a
   unidirectional stream for the "BMP control channel". The control
   channel is used to send the associated status control information,
   such as BMP session state control messages (Initiation Message and
   Termination Message) and BGP peer relationship state control
   messages (Peer up Notification message and Peer down Notification
   message).

   As the Peer up Notification message is sent over the control
   channel, the BMPoQUIC client may create function channels for the
   peer by using unidirectional QUIC streams. These function channels
   are used to carry the relevant information for specific peer or
   AFI/SAFI.



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   These function channels include one Per-Peer Non-Per-AFI/SAFI
   function channel and several Per-Peer Per-AFI/SAFI function
   channels.

   The Per-Peer Non-Per-AFI/SAFI function channel can be used to carry
   messages only related to peer and not to AFI/SAFI, such as Route
   Mirroring message without AFI/SAFI (if it cannot get AFI/SAFI) and
   Statistics Report message without AFI/SAFI (the Stat Type with not
   specifying Per-AFI/SAFI).

   The Per-Peer Per-AFI/SAFI function channel can be used to transmit
   messages only related to AFI/SAFI for a specific peer, such as Route
   Monitoring message, Route Mirroring message with AFI/SAFI (if it can
   get AFI/SAFI from BGP Message) and Statistics Report message with
   AFI/SAFI (the Stat Type with specifying Per-AFI/SAFI).

   As a Peer down Notification message is sent over the control
   channel, the router SHALL close all the related function channels.
   In the future, the Peer down Notification message may be expanded to
   include AFI/SAFI information, allowing the router to close the
   function channel of the specified AFI/SAFI for a peer.

   According to [RFC7854], Initiation Message MUST be sent as the first
   message after the BMP session comes up. So it must be ensured that
   the Initiation message is the first message sent on each BMP
   channel, meaning that an Initiation message must be sent first for
   every BMP channel establishment.

5. Endpoint Authentication

   BMPoQUIC uses QUIC which uses TLS version 1.3 or greater. Therefore,
   the TLS handshake process can be used for BMPoQUIC endpoint
   authentication. A third-party authentication mechanism can also be
   applied for BMPoQUIC endpoint authentication, such as a TLS client
   certificate.

6. Operational Considerations

   The decision to use BMPoQUIC instead of the TCP-based mechanism in
   [RFC7854] is an operational decision, and an implementation MUST
   provide a configuration mechanism to enable BMPoQUIC on the BMP
   session.

   Some connectivity problems (such as blocking UDP) could result in a
   failure to establish a QUIC connection. When this happens, monitored
   router SHOULD attempt to establish a TCP-based BMP session.



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7. IANA Considerations

   This document creates a new registration for the identification of
   BMPoQUIC in the "Application Layer Protocol Negotiation (ALPN)
   Protocol IDs registry established in [RFC7301].

   The "BMPoQ" string identifies BMPoQUIC:

   *  Protocol: BMPoQUIC

   *  Identification Sequence: 0x42 0x4d 0x50 0x6f 0x51 ("BMPoQ")

   *  Specification: This document

8. Security Considerations

   This document replaces the transport protocol layer of BMP from TCP
   to QUIC. The basic protocol specification of BMP is not modified,
   and therefore the new security risks are not introduced to the basic
   BMP protocol. BMPoQUIC enhances transport-layer security for BMP
   session according to [RFC9000].

   This document does not require to support third-party authentication
   (e.g., backend Authentication) due to the fact that TLS does not
   specify this way of authentication. If third-party authentication is
   needed, TLS client certificates are recommended to be used here.

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/rfc/rfc2119>.

   [RFC7854] Scudder, J., Ed., Fernando, R., and S. Stuart, "BGP
             Monitoring Protocol (BMP)", RFC 7854, DOI
             10.17487/RFC7854, June 2016, <https://www.rfc-
             editor.org/info/rfc7854>.

   [RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
             Multiplexed and Secure Transport", RFC 9000, DOI
             10.17487/RFC9000, May 2021, <https://www.rfc-
             editor.org/info/rfc9000>.




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9.2. Informative References

   [RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan,
             "Transport Layer Security (TLS) Application-Layer Protocol
             Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301,
             July 2014, <https://www.rfc-editor.org/info/rfc7301>.

   [I-D.draft-retana-idr-bgp-quic]

             Retana, A., Qu, Y., Haas, J., Chen, S., and J. Tantsura,
             "BGP over QUIC", Work in Progress, Internet-Draft, draft-
             retana-idr-bgp-quic-05, 7 July 2024,
             <https://datatracker.ietf.org/doc/html/draft-retana-idr-
             bgp-quic-05>.


































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Authors' Addresses

   Yisong Liu
   China Mobile
   China
   Email: liuyisong@chinamobile.com


   Changwang Lin
   New H3C Technologies
   Beijing
   China

   Email: linchangwang.04414@h3c.com


   Thomas Graf
   Swisscom
   Binzring 17
   CH- Zurich 8045
   Switzerland
   Email: thomas.graf@swisscom.com

   Paolo Lucente
   NTT
   Veemweg 23
   3771 Barneveld
   Netherlands
   Email: paolo@ntt.net



















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