Hello Paul,
If you are searching for video examples, I just want you to know that, if
you have time available, that you can make your own experiment results using
the Evalvid-RA simulation tool found at
http://www.item.ntnu.no/~arnelie/Evalvid-RA.htm. This tool enables you to
make rate adaptive MPEG-4 video over TFRC, over non-adaptive UDP, and some
more possibilities. You can play the resulting videos using standard players
such as QuickTime and Mplayer. It uses ns-2 and the ffmpeg encoder, which
you have to install from elsewhere.
Best regards
Arne Lie
SINTEF/NTNU, Norway
----- Original Message -----
From: "Paul D. Amer" <amer@xxxxxxxxxxxx>
To: <dccp@xxxxxxxx>
Sent: Friday, November 30, 2007 8:00 PM
Subject: Some general feedback on teaching DCCP
First:
I'm teaching a graduate networking class that includes
DCCP as a new experimental protocol. I want to show
students various simple examples. In particular I want to show
which data is delivered (or read by the receiving application)
for different sizes of receive windows, and with/without
loss of DCCP packets. Best I can tell,
the RFC doesn't contain examples. Does anyone know
if any are available elsewhere?
Second:
After reading the RFC, it's my understanding that
DCCP provides 'in-order, maybe-loss, no duplicate,
controlled/partial data integrity' service.
(TCP provides 'in-order, no-loss, no duplicate, full
data integrity' service.)
Am I correct that the data delivered to the receiving
application will be in order and never have duplicates,
(albeit with some data missing, and possibly
some bits in error for those data fields not covered
by the checksum)?
For example, if a sender sends DCCP packets 1,2,3,4,5,6,
the following are valid deliveries to the receiving app:
1,2,3,4,5,6
1,3,4,6
1,6
and the following deliveries may not occur:
2,1,3,4,5,6
1,2,2,2,3,4,5,6
If my understanding is correct, it would help
the RFC intro to explicitly discuss that DCCP service provides
in-order and no-duplicates (just like TCP). If
my understanding is incorrect, it would help the
RFC to have an example or two showing how data
is delivered to the receiver out-of-order or
in duplicate.
Thanks,
Paul Amer, Professor
Univ of Delaware
