Hi James,
I have thought of a scenario and will like to query u abt it.
Scenario:=20
An Linux LER is within a Diffserv domain. Thus, it receives non-MPLS =
packets with their DSCP marked.=20
For packets flowing into the MPLS domain, the LER has to:
a) Convert the DSCP to EXP marked in the shim header via ds2exp
b) For its outgoing interface, it has to convert the EXP mark into a =
tc_index for the traffic scheduler (tc) to police via exp2tc
For packets flowing out of the MPLS domain, the LER has to:
a) Convert the EXP of the incoming MPLS packet to DSCP via exp2ds
b) Use the DSCP to police the outgoing traffic via the traffic =
schedular (tc).
Am I right to say that:
1) exp2tc is only for outgoing labels and is executed BEFORE the traffic =
scheduler (tc) does its scheduling using the tc_index?
2) ds2exp, exp2ds, set_exp, expfwd will be executed before exp2tc if the =
instructions are executed before i.e
mplsadm -v -A -O gen:41:eth0 -o ds2exp:0xff:0x1a:0x1
mplsadm -v -O gen:41:eth0 -o exp2tc:0xff:0x1:0x2
mplsadm -v -O gen:41:eth0 -o push:gen:41:set:eth0:ipv4:192.168.0.1
The above will map DSCP(0x1a) to EXP(1) and will then convert EXP(1) to =
tc_index(2).
I can then use the traffic scheduler tc to police the traffic based on =
the tc_index 2.
3) Are the above instructions executed correctly?
Thanks.
Paul
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