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Re: Asymmetric Link???
I am the author of this code. Kevin's explanation is correct.
Here are a few more details.
TCP/Asym includes sender-side extensions to TCP to handle asymmetry
better. These include timer-driven transmission of packets when acks
are few and far between, and cwnd growth based on the amount
of data acked rather than the number of ack packets.
TCPSink/Asym includes receiver-side extensions to TCP. This is
primarily "ack congestion control", which varies the frequency
of acks depending on the level of congestion along the ack
path (think of it as a generalized version of TCP delayed ack
with an ack sent for every n data segments, where n is varied
dynamically).
You can choose to use neither, either one, or both. Using both
would result in the best performance. Note that both the sender
and receiver-side extensions are designed to be adaptive;
neither has explicit knowledge of asymmetry in the network.
If you are interested, a Mobicom '97 paper describing some of this
is available from:
http://http.cs.berkeley.edu/~padmanab/papers/mobicom97.ps
http://http.cs.berkeley.edu/~padmanab/papers/mobicom97.ps.gz
-Venkat
> >
> > From: [email protected] (Harlisya Harun)
> > To: [email protected]
> > cc: [email protected], [email protected]
> > Subject: Asymmetric Link???
> > Date: Thu, 20 Aug 1998 11:48:00 BST
> >
> > Hi,
> > I am a bit confuse about these two terms: Asymmetric and Source Asymmet
> ric, for example:
>
> I didn't write this stuff (someone on the ns-users list might be
> able to clarify better), but it looks to me like asym means
> the TCP source and sink use
> special knowledge designed for asym links [in the case of the
> receiver this means reacting to ACK congestion],
> whereas 'asymsrc' only uses the asym source TCP and instead
> uses a conventional TCP receiver [no special handling of ACKs].
>
> - K
>