On 1/12/22 4:15 PM, Josh Luthman wrote:
I would have to imagine any QOS/traffic shaping is done in the OMCI and
hence would probably be in the GPON spec, g.984. I would look there.
Just guessing it would hold true with XG/s/PON, NGPON, etc.
The way at least my gear (Adtran) works is that you configure
shaping/policing as part of the provisioned service. That information
is communicated to the ONTs via the OMCI.
AFAIK, the ONT enforces admission control on the upstream (and
coordinates for timeslot assignments with the OLT since upstream
oversubscription is supported and common), and the OLT enforces
downstream egress control.
You can configure whether you want rate control to be based on hard
policers (instantaneous drop once CIR+CBS+EIR+EBS is exceeded) or
whether you want it to "shape" the traffic by delaying things. The
latter is usually more user-friendly and certainly easier to set up, but
it can result in bufferbloat, and they don't provide very friendly knobs
to tune the maximum queue length. I haven't heard any real complaints
from folks. DSLReports gives me like a C for bufferbloat but doesn't
really make it clear why. The queue is, at most, a few ms in depth.
You can tell it to honor 802.1p CoS, IP ToS, or IP DSCP in various ways
and map them to separate queues with separate policers/shapers and WRR
priority. This is semi-automated if you are doing voice/video via their
provisioning environment.
YMMV on other vendors' gear.
