[Meta] Evaluate protocol transport mechanisms

[markafoltz]

This work item covers the evaluation of alternatives for the protocol transport. Once a presentation display has been discovered, the transport provides a message-oriented channel for controlling the presentation receiver.

Two initial alternatives:

• QUIC Evaluate QUIC as a protocol transport #9
• TLS socket + RTC DataChannel (Mozilla proposal) Evaluate Mozilla proposal as a protocol transport #10

Additional possibilities are HTTP/2, WebSockets, or a custom protocol over TCP or UDP. These can additionally be evaluated once the initial alternatives are done.

[markafoltz]

The alternatives should be evaluated for:

• Functional
• Reliability
• Latency to establish a new connection
• Latency to transmit a presentation connection message, both text and binary
• Ease of implementation / deployment
• Privacy: what device or application information is exposed
• Network efficiency
• Power efficiency
• IPv4 and IPv6 support
• Standardization status and likelihood of successful interop
• Security: how can the transport be made secure (authenticated and private)

[markafoltz]

Both #9 and #10 have been closed with initial evaluations. Followup items to improve them with additional research are tracked separately. Nice job everyone!