I have studied Diffserv and made an experiment in Linux kernel 2.4.x
but I have a question?
At first, supposed the input link capacity of diffserv's edge(ingress) router is more capacity than output link.
that is, total Edge1's input BW is 20Mbps, total Edge1's ouput BW is 10Mbps
+++++++++++++++++++++++++++++++++++
+-------+ 10M Link + DS Domain +
| Host1 |----+ + +
| | | + +
+-------+ | + +-------+ +------+ +-------+ + +-------+
+---------> | Edge1 |-->| Core |-->| Edge2 |---------->| Host3 |
+---------> | | ^ | | ^ | | + ^ | |
+-------+ | + +-------+ | +-----+ | +-------+ + | +-------+
| Host2 | | + | | + |
| |-----+ + 10M Link 10M Link + 10M Link
+-------+ 10M Link + +
+++++++++++++++++++++++++++++++++++
At second, Host1 sends AF1(2.5M), AF2(2.5M), AF3(2.5M), AF4(2.5M) - that is , total 10M traffic - to Host3 host.
Host2 sends best effort (6M) traffic to d1 host.
total sending traffic is 16M.
At third, Edge1's ingress using u32 filter and classfy AF1, AF2, AF3, AF4, BF and marking classid on skb->tc_index.
This architechture is similar to http://qos.ittc.ukans.edu/DiffSpec/node11.html
At this time, both the user Host1, Host2's traffic is not guaranteed in existing tc architecture
because the result of Host1,Host2 traffic metering is not marked in the Edge1's input part,
queue of Edge1's output has only a FIFO queue.
As this output's sch_dsmark has a FIFO queue, Best effort traffic and AF classes traffic is
combined and does not guaranteed AF classes.
Existing sch_ingress and sch_dsmark architecture in edge router(Edg1) is
following that... http://dcn.ssu.ac.kr/~peniel5/zboard/zboard.php?id=diffserv
here, input device uses sch_ingress, output device uses sch_dsmark
as you see, mark of the traffic(af) is end part ( output device ) in this picture.
Therefore, in this circumstance, I think that existing TC structure in Linux kernel 2.4.x is not availble.
Do you have another idea?
I think wrong thing?
well.. I think I have right idea.
and.. finally,
I have a suggestion!
To solve these demerits, I made ingress marker in linux kernel 2.4.x.
that is, I take DSCP marking part 's position in input device part .
the result, architecture of these experiments and performance test
( existing architecture VS suggested architecture ) showed in my web board
my web board is http://dcn.ssu.ac.kr/~peniel5/zboard/zboard.php?id=diffserv
I hope your opinion !!!!!
