BEGIN { dmax=100 if (!(linespeed > 0)) linespeed = 128 FS=":" n = 0 } ($1 != "") { n++ class[n] = $1 prio[n] = $2 avgrate[n] = ($3 * linespeed / 100) pktsize[n] = $4 delay[n] = $5 maxrate[n] = ($6 * linespeed / 100) qdisc[n] = $7 filter[n] = $8 } END { allocated = 0 maxdelay = 0 for (i = 1; i <= n; i++) { # set defaults if (!(pktsize[i] > 0)) pktsize[i] = 1500 if (!(prio[i] > 0)) prio[i] = 1 allocated += avgrate[i] sum_prio += prio[i] if ((avgrate[i] > 0) && !(delay[i] > 0)) { sum_rtprio += prio[i] } } # allocation of m1 in rt classes: # sum(d * m1) must not exceed dmax * (linespeed - allocated) dmax = 0 for (i = 1; i <= n; i++) { if (avgrate[i] > 0) { rtm2[i] = avgrate[i] if (delay[i] > 0) { d[i] = delay[i] } else { d[i] = 2 * pktsize[i] * 1000 / (linespeed * 1024) if (d[i] > dmax) dmax = d[i] } } } ds_avail = dmax * (linespeed - allocated) for (i = 1; i <= n; i++) { lsm1[i] = 0 rtm1[i] = 0 lsm2[i] = linespeed * prio[i] / sum_prio if ((avgrate[i] > 0) && (d[i] > 0)) { if (!(delay[i] > 0)) { ds = ds_avail * prio[i] / sum_rtprio ds_avail -= ds rtm1[i] = rtm2[i] + ds/d[i] } lsm1[i] = rtm1[i] } else { d[i] = 0 } } # main qdisc for (i = 1; i <= n; i++) { printf "tc class add dev "device" parent 1:1 classid 1:"class[i]"0 hfsc" if (rtm1[i] > 0) { printf " rt m1 " int(rtm1[i]) "kbit d " int(d[i] * 1000) "us m2 " int(rtm2[i])"kbit" } printf " ls m1 " int(lsm1[i]) "kbit d " int(d[i] * 1000) "us m2 " int(lsm2[i]) "kbit" print " ul rate " int(maxrate[i]) "kbit" } # leaf qdisc avpkt = 1200 for (i = 1; i <= n; i++) { printf "tc qdisc add dev "device" parent 1:"class[i]"0 handle "class[i]"00: " # RED parameters - also used to determine the queue length for sfq # calculate min value. for links <= 256 kbit, we use 1500 bytes # use 50 ms queue length as min threshold for faster links # max threshold is fixed to 3*min base_pkt=3000 base_rate=256 min_lat=50 if (maxrate[i] <= base_rate) min = base_pkt else min = int(maxrate[i] * 1024 / 8 * 0.05) max = 3 * min limit = (min + max) * 3 if (qdisc[i] != "") { # user specified qdisc print qdisc[i] " limit " limit } else if (rtm1[i] > 0) { # rt class - use sfq print "sfq perturb 2 limit " limit } else { # non-rt class - use RED avpkt = pktsize[i] # don't use avpkt values less than 500 bytes if (avpkt < 500) avpkt = 500 # if avpkt is too close to min, scale down avpkt to allow proper bursting if (avpkt > min * 0.70) avpkt *= 0.70 # according to http://www.cs.unc.edu/~jeffay/papers/IEEE-ToN-01.pdf a drop # probability somewhere between 0.1 and 0.2 should be a good tradeoff # between link utilization and response time (0.1: response; 0.2: utilization) prob="0.12" rburst=int((2*min + max) / (3 * avpkt)) if (rburst < 2) rburst = 2 print "red min " min " max " max " burst " rburst " avpkt " avpkt " limit " limit " probability " prob " ecn" } } # filter rule for (i = 1; i <= n; i++) { print "tc filter add dev "device" parent 1: prio "class[i]" protocol ip handle "class[i]"/0xff fw flowid 1:"class[i] "0" filterc=1 if (filter[i] != "") { print " tc filter add dev "device" parent "class[i]"00: handle "filterc"0 "filter[i] filterc=filterc+1 } } }