[e2e] Routers accessing TCP header
Jon.Crowcroft at cl.cam.ac.uk
Mon Feb 21 03:53:19 PST 2005
anything is possible given enough money...
depends on the router
deep packet inspection takes lotsa cycles or usesup valuble logic
in any custom processor stuff on line cards, or
means your packet goes to the control procxessor ("slow path") but
also messes up any router that has seperate paths for the headers
or any router with a switch that turns packets into cells etc etc etc
will all make life very hard
if its a zebra/xorp/gated or any other unix variant,
then its probably about as easy as changing ns...and about as reliable:)
depends on the packet
if its crypted, you lose
Hack proposal: copy the TCP sequence number into the IP Id field then its in the normal IP header
(yes i know the TCP sequence number is 32 but, but it usually varies by a MSS size, and you could just put the
deltas in the IP field - surely noone depends on them going ++ (they'd stil be _monotocally_ increaseing,
just less monotonously:)
and the ip frag stuff would still all work right?
In missive <64188.8.131.52.3.1108984266.squirrel at 184.108.40.206>, "Arjuna Sathiaseelan" typed:
>> I have implemented a mechanism which requires routers to access the TCP
>>header from the IP packet mainly the TCP sequence numbers. Implementing
>>this on ns-2 is not a problem. But in real world, is this a possibility?
>>Can the routers access the TCP header mainly the TCP sequence numbers? I
>>would be very much obliged if someone could help me with this.
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