Technical Summary
DCCP communications as defined in RFC 4340 are restricted to a single
path per connection, yet multiple paths often exist between peers.
The simultaneous use of available multiple paths for a DCCP session
could improve resource usage within the network and, thus, improve
user experience through higher throughput and improved resilience to
network failures. Use cases for Multipath DCCP (MP-DCCP) are mobile
devices (e.g., handsets, vehicles) and residential home gateways
simultaneously connected to distinct networks as, e.g., a cellular
and a Wireless Local Area (WLAN) network or a cellular and a fixed
access network. Compared to existing multipath protocols such as
MPTCP, MP-DCCP offers special support for latency-sensitive services
with different requirements for reliability and in-order delivery.
This document specifies a set of extensions to DCCP to support
multipath operations. The protocol offers the same type of service
to applications as DCCP and provides the components necessary to
establish and use multiple DCCP flows across different paths
simultaneously.
Working Group Summary
There was discussion about whether the requirements as represented by
ATSSS from 3GPP would be addressed by this spec or by other means. It
was not the responsibility of the IETF to decide on the different
technologies that might be used, and there was support for progressing
this specification as one alternative that could be realised.
Document Quality
There is one fork of the Linux tree that includes support for this
extension. This was demonstrated at IETF Hackathons and the results
reported to the TSVWG. See also: https://multipath-dccp.org/.
Personnel
The Document Shepherd for this document is Gorry Fairhurst. The
Responsible Area Director is Gorry Fairhurst (formerly Zaheduzzaman
Sarker).