Yes but wouldn't you need to know the size of *each* TCP packet?....

I assume you don't need an explicit TCP length field because
you can calculate the TCP packet length by substracting the TCP header
length from the *IP packet* length.  (IP packets *do* have length
field.)

Since you can do the same for UDP it still appears that the UDP length
field is redundant and unnecessary.

Chris



On Fri, 2005-11-18 at 10:45 -0800, Michael O'Keefe wrote:
> Christian Seberino wrote:
> > I noticed that UDP has a total length field (bytes 5 & 6)
> > but TCP does NOT!  (TCP has a header length field only
> > which is half of byte 13)
> 
> a UDP packet is the entire message. Each UDP packet is self contained. 
> TCP packets are part of a stream, a fragment of the whole stream. So 
> nobody knows how long the stream is.
> 
> 
> -- 
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