[e2e] application layer -SCTP!!!!

[Srinivas Krishnan]

SCTP does seem to provide on the outside a very nice interface
borrowing congestion control from TCP and the concept of various
streams. However, the experiences we had with SCTP are not too good,
especially with the PR-SCTP. We at UNC-CH wanted a protocol that lets
choose on the application layer conditions whether we wanted a fully
reliable protocol or just a best-effort protocol. Unfortunately the 2
implementations of SCTP: SCTPLIB (a user level package) or the kernel
level implementation in Linux do not fully support partial reliability
or a way of making per packet/object decision of whether we wanted
full reliability, partial etc.

In the end we rolled out our own protocol based on UDP using TFRC as a
congestion control algorithm (based it on the sender side). The
protocol lets us choose whether we wanted to provide full reliability,
partial reliability based on the application. We even have a module
which does a form of congestion control in the application itself.
This is for a video adaptation and hence based on latency we always do
not need to send the next packet as the time for display on the client
might have passed.

I will describe some more of our work on video adaptation on a separate post.

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Srinivas Krishnan

Graduate Student
Dept. Of Computer Science
UNC-Chapel Hill
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 Phone:
   **Office: (919) 962-1920
   **Cell:    (585)295-3359
 Email: krishnan at cs.unc.edu, shrin.krishnan at gmail.com
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 Web: www.cs.unc.edu/~krishnan
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