Re: [aqm] thoughts on operational queue settings (Re: [tsvwg] CC/bleaching thoughts for draft-ietf-tsvwg-le-phb-04) (fwd)

[Mikael Abrahamsson <[e-mail]>]

On Thu, 12 Apr 2018, Mikael Abrahamsson wrote:

> I am also going to test a 3 queue setup, where each of these groups of 
> DSCP values would go into different queues where LE would perhaps be 
> assured 5% of BW and the rest split evenly between a BE and "everything 
> else" queue. If I did that, I would probably not start dropping LE 
> traffic until 10-20ms buffer fill.

I tried the following configuration which yielded expected results. Good 
thing here is that if you fill up BE and run some !BE (mikabr-rest class) 
then it basically doesn't get any added delay at all.

There were no hits on class-default, I just keep it there in case there is 
some traffic that won't be matched by the others. I tried speeds down to 
10 megabit/s, where the BE RED profile causes significant buffer delay, up 
to 30-40ms with 10 concurrent TCP sessions. So these values are not "one 
size fits all", but they're at least much better than FIFO with huge 
buffers and LE is well controlled compared to the other traffic.

Again, I'm aiming to write up something about this for people to take to 
replace their overbuffered FIFOs they might have towards customers today, 
not produce something that is wonderfully great, but not widely supported 
in current hw.

policy-map OUT-QOS-SERVICE-1-2011
  class mikabr-BE
   random-detect 10 ms 1000 ms
   bandwidth percent 40
  !
  class mikabr-LE
   random-detect 10 ms 1000 ms
   bandwidth percent 5
  !
  class mikabr-rest
   random-detect 10 ms 1000 ms
   bandwidth percent 40
  !
  class class-default
   bandwidth percent 5
  !
  end-policy-map

policy-map OUT-QOS-1-2011
  class class-default
   service-policy OUT-QOS-SERVICE-1-2011
   shape average 400 mbps 100 us

class-map match-any mikabr-BE
  match dscp 0 2-7
  end-class-map
!
class-map match-any mikabr-LE
  match dscp 1 8
  end-class-map
!
class-map match-any mikabr-rest
  match dscp 9-63
  end-class-map


-- 
Mikael Abrahamsson    email: [e-mail]