Re: [Taps] Drive-by comments on draft-fairhurst-taps-transports-usage-udp-01

[[e-mail] (Dale R. Worley)]

[e-mail] writes:
> I agree - the current format from the text comes from the existing text 
> for TCP and SCTP in another draft. and I think we  may need to work out
> how to handle
> [...]
> I probably need help - I think there are different many ways in which UDP
> uses ports. Offers from anyone on how to get started would be great.

Even in TCP, the semantics of connection setup is more complicated that
you'd think at first.  If I have it correctly, it runs:

	Passive		Active
	Endpoint	Endpoint

	Create socket
	Bind socket to listening address
	Activate listening

			Create socket
			Connect

	Incoming connection event
	Accept connection

At least in the protocol, it's possible for both endpoints to be active,
but they have to have prior agreement regarding the addresses and ports
and send their initial packets within one RTT of each other, so I don't
know if that possibility is ever used in practice.  Or whether the
Berkeley sockets API supports it.

OTOH, the TAPS work might not be attempting to capture the semantics of
connection setup.

The process for UDP is not much simpler.  My memory is:

	Passive		Active
	Endpoint	Endpoint

	Create socket
	Bind socket to listening address

			Create socket
			Send-to -or- Connect, then Send

	Incoming connection event
	Connect (in the TAPS paradigm)
	Incoming packet event
	Receive packet

Dale