[e2e] bytes vs. packets
dhc2 at dcrocker.net
Sat Aug 9 07:46:26 PDT 2003
VS> contributor has for years bemoaned the great mistake made in TCP of
VS> counting bytes instead of records as in x.25 and as far as I can tell
VS> never did understand the TCP window.
I'd like to get a bit of discussion on this choice. Not debate about
TCP, but clarification about the trade-off in the choice between
datagram-counting and byte-counting.
The DCCP spec uses packets, not bytes, and it is being produced by
knowledgeable folk. So it's worth being clear when each choice makes
Also the absence of a record-marker in TCP has often been a pain. Now, I
can understand separating application-level constructs, like "record"
from network-level transfer constructs, like datagram. However the need
for record markers is considerable.
As I recall, the compelling argument for byte-counting, in TCP, was that
TCP was permitted to re-frame the data, as it saw fit. So there was no
guarantee that the datagram boundaries would be preserved.
Dave Crocker <mailto:dcrocker at brandenburg.com>
Brandenburg InternetWorking <http://www.brandenburg.com>
Sunnyvale, CA USA <tel:+1.408.246.8253>, <fax:+1.866.358.5301>
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