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Re: [ns] ftp with FullTCP: packet size
On Sun, 17 Sep 2000, Julian Waldby wrote:
> I am running simulations of a ftp application over fulltcp. I want to set the
> packet sizes it sends with to 1000 bytes. However, even though I have set both
> the fulltcp agent to packetsize 1000 bytes:
>
> set tsnd0 [new Agent/TCP/FullTcp]
> $tsnd0 set packetSize_ 1000
use
$tsnd0 set segsize_ 1000
This is because FullTcp attempts to approximate header overhead, while
one-way TCP doesn't. At all. If you think about layering, setting
packet size at the TCP level is silly - what about the IP level? So
packetSize_ doesn't mean anything to FullTcp. It's in the docs.
This comes up in discussion of headers every so often. I can imagine
ns eventually implementing a real shim IP layer handling header
addition and subtraction...
L.
<[email protected]>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>