Subject: WG Review: Multiplexed Application Substrate over QUIC Encryption (masque)

From: The IESG <[email-masked]>
Date: Fri, 22 May 2020 11:14:41 -0700

A new IETF WG has been proposed in the Transport Area. The IESG has not made
any determination yet. The following draft charter was submitted, and is
provided for informational purposes only. Please send your comments to the
IESG mailing list ([email-masked]) by 2020-06-01.

Multiplexed Application Substrate over QUIC Encryption (masque)
-----------------------------------------------------------------------
Current status: Proposed WG

Chairs:
  Christopher Wood <[email-masked]>
  Eric Kinnear <[email-masked]>

Assigned Area Director:
  Martin Duke <[email-masked]>

Transport Area Directors:
  Magnus Westerlund <[email-masked]>
  Martin Duke <[email-masked]>

Mailing list:
  Address: [email-masked]
  To subscribe: https://www.ietf.org/mailman/listinfo/masque
  Archive: https://mailarchive.ietf.org/arch/browse/masque/

Group page: https://datatracker.ietf.org/group/masque/

Charter: https://datatracker.ietf.org/doc/charter-ietf-masque/

Many network topologies lead to situations where transport protocol proxying
is beneficial. For example, proxying enables endpoints to communicate when
end-to-end connectivity is not possible and can apply additional encryption
where desirable (such as a VPN). Proxying can also improve client privacy,
e.g., by hiding a client's IP address from a target server.

Proxying technologies such as SOCKS and HTTP(S) CONNECT exist, albeit with
their own shortcomings. For example, SOCKS signalling is not encrypted and
HTTP CONNECT is currently limited to TCP. In contrast, HTTP/3 is a viable
candidate protocol for proxying arbitrary traffic, as in a single connection
it provides secure connectivity, multiplexed streams, migration, and a
unified congestion controller. An HTTP/3 datagram construct built on top of
QUIC datagram frames would provide for unreliable data transmission and
enable transporting UDP and other unreliable flows via a proxy. Moreover, it
would not introduce potentially redundant or unnecessary recovery mechanisms.
Lastly, HTTP supports an established request/response semantic that can set
up and configure flows for different services.

The primary goal of this working group is to develop mechanism(s) that allow
configuring and concurrently running multiple proxied stream- and
datagram-based flows inside an HTTPS connection. These mechanism(s) are
collectively called MASQUE. The group will specify HTTP and/or HTTP/3
extensions to enable this functionality. The group will focus on a limited
set of client-initiated services: (1) UDP CONNECT and (2) IP proxying.
Server-initiated services are out of scope. The working group will first
deliver a protocol solution for UDP CONNECT and a requirements document for
IP proxying. Once both are complete, the working group will focus on a
protocol solution for IP proxying.

The working group will consider fallback to versions of HTTPS that operate
over TCP as a mitigation to UDP or HTTP/3 blocking. Moreover, the working
group will consider implications of tunneling protocols with congestion
control and loss recovery over MASQUE, and may issue recommendations
accordingly. New congestion control and loss recovery algorithms are out of
scope.

Multicast support is out of scope. However, the group may specify extension
points that would enable future work on multicast. Specifying proxy server
discovery mechanisms is also out of scope. However, the group may consider
features, such as proxy server identifiers, that aid future discovery
mechanisms.

Impacts on address migration, NAT rebinding, and future multipath mechanisms
of QUIC are not anticipated. However, the working group should document these
impacts, or those of any other QUIC developments, if they arise.

The group will coordinate closely with other working groups responsible for
maintaining relevant protocol extensions, such as HTTPBIS, QUIC, or TLS. It
will also coordinate closely with ICCRG and TSVWG on congestion control and
loss recovery considerations.

Milestones:

TBD