Howdy All,
I'm attempting to smooth out some traffic on an MX Gig Port on an MX80-T (Trio
Card) running 11.4R2.14 (Yeah, I'm being adventurous here).
The underlying Gig link is going via a carrier lease on one of those
Ethernet-over-SONET jobbies on the Carrier's side; which is limited to 150mbit
(STM-1/OC3); and their gear has notoriously "small" buffer sizes (meaning that
any bursts > 4k are dropped.. yeah, great equipment...). Hence, I need to not
only shape, but control the burst size to get rid of any micro-bursting on the
port. (even a small 50m bursty stream will attempt to burst to line-rate, due
to the token-method that the shaper uses; thus flooding the Carrier's
EoSDH/EoSONET equipment and leading to packet drops).
So to do this, I did:
class-of-service {
traffic-control-profiles {
chrisk-test {
scheduler-map My-Standard-QoS;
shaping-rate 150m burst-size 4k;
}
interfaces {
ge-1/0/9 {
output-traffic-control-profile chrisk-test;
}
ge-1/0/9 is setup as a standard interface, no hierarchal, no-per-unit sched....
just a plain-olde Gig Port. I'm using a tc-profile as it allows setting of a
burst-size; while the standard c-o-s { interfaces { "shaping-rate" }} does not.
However, upon testing, it appears that the burst-size is completely ignored.
(verified with a nice EXFO test set, generating some very bursty traffic).
I have also tried using the following (which are MX/Trio specific, thinking I
have the wrong commands):
shaping-rate-priority-high 150m burst-size 4k;
shaping-rate-priority-medium 150m burst-size 4k;
shaping-rate-priority-low 150m burst-size 4k;
... Also tried differing burst-sizes (4k, 8k, 16k, 32k, etc) and nothing seems
to take effect.
I will note that I did this on a DPCE-Q Card under 10.4Rsomething, and it works
fine in terms of controlling the microbursts. I can also somewhat solve this by
shaping at the per-queue level with a scheduler referencing a shaping-rate X
burst-size 4k and it also works; however, shaping every queue is not a solution
here. (I can explain more on this point if anyone needs...)
Hoping for some collective clue here.... (My next attempt will be to downgrade
to 11.2Rx - but I'm not expecting any love from that version either...)
I highly suspect I'm missing something obvious.
- CK.
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