On Sun, Jul 30, 2006 at 11:52:48PM +0100, Gustavo Homem wrote: > On Sun, Jul 30, 2006 at 11:09:04PM +0200, Daniel Musketa wrote: > > Hello, > > > > I just found the great howto and started shaping my internet connection. > > The > > howto's last update is a liitle in the past now so I have some questions > > about how things are done the best way nowadays ;-) > > > > > > To ensure a stable and low latency voip communication I added an HFSC qdisc > > to > > device ppp0 (1 Mbit SDSL). There are two classes (by now): One for SIP and > > RTP and one for the rest. > > > > Question 1: I defined the voip qdisc as > > > > tc class add dev ppp0 parent 1:1 classid 1:11 \ > > hfsc sc umax 1500b dmax 30ms rate 500kbit ul rate 900kbit > > > > but "tc -s class show dev ppp0" shows > > > > class hfsc 1:11 parent 1:1 sc m1 0bit d 6.0ms m2 500000bit \ > > ul m1 0bit d 0us m2 900000bit > > > > Where does the "0bit d 6.0ms" come from, (what does the other stuff exactly > > mean) and what would be a good setting for voip traffic? > > > > > > > > > > This qdisc only affects outgoing traffic. But I also want to control > > incoming > > packets and keep the isp's queue empty. > > > > Question 2: What is the best solution for doing this: ingress qdisc, IMQ, > > ... > > (thers's only one link to isp)? > > > > If you don't want to patch the kernel and your machine has only two network > interfaces you can shape the outgoing traffic to the internal interface > instead of the incoming traffic to the internal interface. I have an example > script here:
"you can shape the outgoing traffic to the internal interface instead of the incoming traffic to the *external* interface" > > http://downloads.angulosolido.pt/QoS/HTB_shaper_adv.sh > > It uses HTB for shapping though. > > > > > > > > > Much traffic on this line is UDP traffic (OpenVPN). > > > > Question 3: If I do policing on incoming traffic, do UDP transmissions care > > about dropping and reduce transmit speed? > > > > > > I don't think so, unless that is implemented at the application level. The > UDP packets shouldn't be dropped unless that's acceptable to a certain extend > (VoIP) or the application resends as necessary. > > > > > > > > If I begin to control incoming traffic I only want to drop packets that are > > non voip traffic. > > > > Question 4: Is it possible to control what packets are dropped? > > > > Depends if you know the ports they use. If you know it, you just have to mark > them accordingly. > > For example with skype it's a pain in the ass, as it seems not to respect the > port chosen on the configuration. I solved that by reserving bandwidth per > workstation, so that each one get's TOTAL/N, extensible to TOTAL of the > others don't request it. For each workstation there is also a priority rank, > but for cases like skype, whose ports we can't control, it ends up being up > to each user to ensure there's enough bandwidth on her share for skype to > work. > > Take a look at the link I pasted above. > > > > > > > I always want to have enough bandwith for incoming voip traffic. But > > limiting > > the other stuff to static 180 kbit only because voip packets could > > sometimes > > reach a maximum of 800 kbit sounds not so good. > > > > Sure! > > > My idea: A script that periodically (or even better: triggered by asterisk) > > controls the parameters for the ingress shaper (depending on the actual > > upload traffic produced by voip which could easily be measured with tc). > > > > Question 5: Is that possible? Is this necessary at all? Is there already a > > solution? > > > > I don't think you need this. A setup with HTB solves this problem, since each > traffic class has a defined RATE as well as a defined CEIL rate, which it > will take whenever available. > > I can't comment about HFSC as I never used it. > > Best regards > Gustavo > > > > > > > Regards > > Daniel > > _______________________________________________ > > LARTC mailing list > > LARTC@mailman.ds9a.nl > > http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc > > -- > Angulo Sólido - Tecnologias de Informação > http://angulosolido.pt > > _______________________________________________ > LARTC mailing list > LARTC@mailman.ds9a.nl > http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc -- Angulo Sólido - Tecnologias de Informação http://angulosolido.pt _______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
