Re: Bandwidth Prioritization and shuffling
Ritesh Raj Sarraf on Saturday 08 Jul 2006 23:03 wrote:
> Hi,
>
> On my home computer I have a cable modem connection which varies from 64kbps
> to 320kbps.
>
> I use a lot of applications. ssh, ftp, gnutella, http, pop, irc, yahoo, msn,
> gtalk et cetera.
>
> Problems arise when I start to do a big download. All the bandwidth is
> consumed by the big download because of which applications of pop, yahoo, msn,
> ssh and others break.
>
> Is there a way to set something like:
>
> 1) If no one is using the bandwidth, utilize the full bandwidth.
> 2) If high priority apps like ssh, pop, yahoo, msn, pop are running; always
> give them higher priority. Don't eat all the bandwidth.
> 3) If mid priority apps like http, ftp are running; give them higher priority.
> 4) If both high and medium priority applications are running, give both of
> them higher priority. But at the same time don't starve yourself.
>
> I looked at some of the packet queuing docs (lartc and others) but all assume
> you know your full bandwidth.
>
> Ritesh
And at the moment I'm using the following script but am not sure if it is giving
me optimal performance.
But I do see performance improvements. Now my pop3 downloads don't timeout.
rrs@learner:~ $ cat /root/packet_queue_cbq.sh
#!/bin/bash
# The Ultimate Setup For Your Internet Connection At Home
#
#
# Set the following values to somewhat less than your actual download
# and uplink speed. In kilobits
DOWNLINK=320
UPLINK=40
DEV=eth0
# clean existing down- and uplink qdiscs, hide errors
tc qdisc del dev $DEV root 2> /dev/null > /dev/null
tc qdisc del dev $DEV ingress 2> /dev/null > /dev/null
###### uplink
# install root CBQ
tc qdisc add dev $DEV root handle 1: cbq avpkt 1000 bandwidth 10mbit
# shape everything at $UPLINK speed - this prevents huge queues in your
# DSL modem which destroy latency:
# main class
tc class add dev $DEV parent 1: classid 1:1 cbq rate ${UPLINK}kbit \
allot 1500 prio 5 bounded isolated
# high prio class 1:10:
tc class add dev $DEV parent 1:1 classid 1:10 cbq rate ${UPLINK}kbit \
allot 1600 prio 1 avpkt 1000
# bulk and default class 1:20 - gets slightly less traffic,
# and a lower priority:
tc class add dev $DEV parent 1:1 classid 1:20 cbq rate $[9*$UPLINK/10]kbit \
allot 1600 prio 2 avpkt 1000
# both get Stochastic Fairness:
tc qdisc add dev $DEV parent 1:10 handle 10: sfq perturb 10
tc qdisc add dev $DEV parent 1:20 handle 20: sfq perturb 10
# start filters
# TOS Minimum Delay (ssh, NOT scp) in 1:10:
tc filter add dev $DEV parent 1:0 protocol ip prio 10 u32 \
match ip tos 0x10 0xff flowid 1:10
# ICMP (ip protocol 1) in the interactive class 1:10 so we
# can do measurements & impress our friends:
tc filter add dev $DEV parent 1:0 protocol ip prio 11 u32 \
match ip protocol 1 0xff flowid 1:10
# To speed up downloads while an upload is going on, put ACK packets in
# the interactive class:
tc filter add dev $DEV parent 1: protocol ip prio 12 u32 \
match ip protocol 6 0xff \
match u8 0x05 0x0f at 0 \
match u16 0x0000 0xffc0 at 2 \
match u8 0x10 0xff at 33 \
flowid 1:10
# rest is 'non-interactive' ie 'bulk' and ends up in 1:20
tc filter add dev $DEV parent 1: protocol ip prio 13 u32 \
match ip dst 0.0.0.0/0 flowid 1:20
########## downlink #############
# slow downloads down to somewhat less than the real speed to prevent
# queuing at our ISP. Tune to see how high you can set it.
# ISPs tend to have *huge* queues to make sure big downloads are fast
#
# attach ingress policer:
tc qdisc add dev $DEV handle ffff: ingress
# filter *everything* to it (0.0.0.0/0), drop everything that's
# coming in too fast:
tc filter add dev $DEV parent ffff: protocol ip prio 50 u32 match ip src \
0.0.0.0/0 police rate ${DOWNLINK}kbit burst 10k drop flowid :1
--
Ritesh Raj Sarraf
RESEARCHUT - http://www.researchut.com
"Necessity is the mother of invention."
"Stealing logic from one person is plagiarism, stealing from many is research."
"The great are those who achieve the impossible, the petty are those who
cannot - rrs"
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