-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, i''ve been working on VoIP qos in the few weeks. I shape IAX2 and SIP, and i''m getting some interesting results. Im using HTB, the line is 512Kbps dedicated line, and we have some servers on the same line that generate quite a lot of traffic, frequently saturating the link. I''ve read through LARTC how to, example, etc, and so far i''m at this point: I can can shape the servers traffic, based on ip and services I can shape the Voip traffic If i reserve some bandwith for VoIP and the rest for server traffic, it all runs smooth This setup works by creating a root disc, then two "source" disc, one rated at 100 Kbps for voip, one rated 300Kbps. The remaining 100Kbps is "wasted" to avoid buffering from the router But i would like to have the possibility to use all the 400Kbps and slow down server traffic only when and if needed. I prioritized VoIP traffic, using the various scripts around, and what i get is that, even if voip quality is definitely much much better than without shaping, there are is still statics and pops, and some interruption of the voice and only if i''m called from POTS I do not get this when completely reserving the bandwith or when the link is not loaded. i would like to ask if this is a normal behaviour before keeping to try to understand if i missed something somewhere.. if it''s not normal i would post my script and ask for a suggestion. BTW i get the same results when using wondershaper and so on. Thanks, Ricky -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFB8oolwfVi6Z6cQK8RApbVAKCZEb/pfBRv5qaF5crcVSWCnezUaACdFGFz T/ZcbeymTclRyQXd0Rva0i0=Ahk1 -----END PGP SIGNATURE----- _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
On Saturday 22 January 2005 12:15, Riccardo Losselli wrote: <snip>> i would like to ask if this is a normal behaviour before keeping to try > to understand if i missed something somewhere.. > if it''s not normal i would post my script and ask for a suggestion. > BTW i get the same results when using wondershaper and so on.What I found most helpful, when things were not working as I thought I had configured them to, was to graph for a duration and compare the incidents with the graph output. If you can pinpoint spikes on the graph or other events with VoIP issues, you might see if your configuration is at fault. ( Shameless plug: http://trekweb.com/~jasonb/articles/traffic_shaping/monitoring.html ) -- Jason Boxman Perl Programmer / *NIX Systems Administrator Shimberg Center for Affordable Housing | University of Florida http://edseek.com/ - Linux and FOSS stuff _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 | What I found most helpful, when things were not working as I thought I had | configured them to, was to graph for a duration and compare the incidents | with the graph output. If you can pinpoint spikes on the graph or other | events with VoIP issues, you might see if your configuration is at fault. | | ( Shameless plug: | http://trekweb.com/~jasonb/articles/traffic_shaping/monitoring.html ) Thanks.. it will be useful! I''ve just graphed it, and it seems ok.. i can see the root, the four child (three are used to shape each one of the three lines we have, that share the same shaper, one is used to put the traffic going from one of the three local nets to the other, which i do not want to be shaped) and their respective child, and finally the leaf classes (question: is it necessary to attach a leaf sfq or pfifo class to make things work? i guess no, it''s just used to give fairness to each connections sent to the class, right?) I can also se the filters that use "mark" policy go directly to the root class. I did not understand exactly why filters are attached to the root qdisc, and not to the qdisc they refer too, but i guess it''s a correct behavious as i see it in every script around... i''ll try to see if i can understand alittle more with the traffic graphs too.. Thanks again, Ricky -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFB8rF6wfVi6Z6cQK8RAsg2AJ46TBdg0lDMlRNOUByF4zjlsVlcKgCguVOI bZ1kpiUVVh8rbXBnseNBAq8=X6Mx -----END PGP SIGNATURE----- _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Thanks again to Jason.. i plotted the classes and they are as i wished them to be.. I also plotted the traffic, while heavily using the link. I gave Voip a 100Kbit rate (it need between 80 and 90some) and it worked. There are no visibile spikes (traffic si not exactly flat, but variations are minimal) and stay betwen 80Kbps and 90some. So it should be fine.. traffic is prioritarized, prio 1, while the other traffic is 3 or more.. Leaf classes are sfq perturb 10 I still hear the pops.. If it can be a useful hint, the problem appears only when i''m called, not when i call (i use two diffent servers when making calls and receiving). The only one who hears the pops i the one on the POTS phone that is calling me, i do not hear any pop (but i guess it''s because my link is saturated upstream only) At first i thought that it was a problem of the server used to call me. but if I the almost zero the non voip traffic the pops disappear... Will test more... Bye, Ricky -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFB9A8dwfVi6Z6cQK8RAmg2AJ9Wa7bonOslMsRm6sInLrKA438gHgCdFcge cYm/fGsXo7XJ5KkHLXD+Mo0=FzbA -----END PGP SIGNATURE----- _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
> But i would like to have the possibility to use all the 400Kbps and slow > down server traffic only when and if needed. > > I prioritized VoIP traffic, using the various scripts around, and what i > get is that, even if voip quality is definitely much much better than > without shaping, there are is still statics and pops, and some > interruption of the voice and only if i''m called from POTS > I do not get this when completely reserving the bandwith or when the > link is not loaded.You probably forgot to tweak the HTB code to change the hysterisis value? This helps a lot with the output stuff. However, remember that you always have to slow down the incoming to a little less than max otherwise by the time the stuff is throttled you see some small amount of queuing at the remote end. Also remember that the bandwidth of most adsl links is less than the stated bandwidth. This is because of ATM overheads (which vary depending on packet size) and also because the link is contended. Put this all together and you should be able to get pretty close to maximum,. perhaps only reserving a small amount of bandwidth and make the rest shareable. Good luck Ed W _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Ed Wildgoose wrote: | Please reply onlist in general | Sorry, i didn''t notice the answer went to you only.. i did the same mistake with Jason. | Check the HTB code in iproute and look for the "hysteris" variable. | Basically it just lets a couple of packets burst out at the same time | instead of doinga very granular per packet throttling. ok.. | Find out what the protocol is on the line. ADSL for example uses ATM to | encapsulate each packet. YOu buy 512Kbs of ATM bandwidth, which | actually works out as somewhat less TCP bandwidth (which is what you are | throttling). So do some speed tests on the line and work out the REAL | speed of the line. Preferably use small packets since the overhead of | encapsulation often shoots up then. | | This might not be relevant though - just a warning though I understand it''s a frame relay | I meant, reserve (say) 10Kbs, and only share the rest... I see.. this way it works. Things are getting a little more complicated though.. I tested with some people, calling ip to ip, and it works just fine. I understand that, if it''s just a matter of my bandwith being overloaded and not correctly shaped i should get the same disturbs, but i do not. I suspect there is something involved on the server that converts the call from ip to POTS and vice versa too.. Thanks! Ricky -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFB9hXNwfVi6Z6cQK8RAoMNAJ9p8OJ1amuS+y0VKVla/CTZRwuwugCfT3xK rMU221VkLji/lhh3t4xXbKk=JZ5A -----END PGP SIGNATURE----- _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/