RFC 10069: Managing Multiple Paths for a QUIC Connection

This document specifies a multipath extension for the QUIC protocol to enable the simultaneous usage of multiple paths for a single connection. It introduces explicit path identifiers to create, delete, and manage multiple paths. This document does not specify address discovery or management, nor how applications using QUIC schedule traffic over multiple paths.¶
This is an Internet Standards Track document.¶
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.¶
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc10069.¶
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1.1. Conventions and Definitions
2. Connection Lifecycle and Packet Protection
2.1. initial_max_path_id Transport Parameter
2.2. Relation to Other Transport Parameters
2.3. Handling ACK and PATH_ACK in 0-RTT and 1-RTT
2.4. Nonce Calculation after Handshake Completion
2.5. Key Phase Update Process
2.6. Connection Closure
3.1. Path Initiation and Validation
3.1.1. Path Establishment Example
3.1.2. Relation to Probing and Migration
3.1.3. Address Validation Token
3.2. Handling Connection IDs
3.2.1. Issuing New Connection IDs
3.2.2. Rotating and Retiring Connection IDs
3.3. Path Status Management
3.4.1. Path Closure Example
3.4.2. Avoiding Spurious Stateless Resets
3.4.3. Handling PATH_ACK for Abandoned Paths
4.2. PATH_ABANDON Frame
4.3. PATH_STATUS_AVAILABLE and PATH_STATUS_BACKUP Frames
4.4. PATH_NEW_CONNECTION_ID Frame
4.5. PATH_RETIRE_CONNECTION_ID Frame
4.6. MAX_PATH_ID Frame
4.7. PATHS_BLOCKED and PATH_CIDS_BLOCKED Frames
5. Implementation Considerations
5.1. Connection ID Changes, Migration, and NAT Rebindings
5.2. Using Multiple Paths on the Same 4-tuple
5.3. Congestion Control
5.4. Computing Path RTT
5.5. Packet Scheduling
5.6. Retransmissions
5.8. Paths Having Different PMTU Sizes
5.9. Idle Timeout and Keep-Alives