Re: [LARTC] HFSC and that ATM overhead problem (Another VOIP QoS post. Ahhhh)
On Sunday 04 November 2007 12:04, Fog_Watch wrote: G'Day I would like to be able to use my VOIP telephone over a saturated ADSL link whilst enjoying optimum audio quality and utilising all of the bandwidth I pay for. It is about this situation that I write. HFSC appears to be the queueing discipline of choice for VOIP. In order for this to work, though, do I have to account for the ATM overhead in the small VOIP packets by defining my maximum root class bit rate as (measured max bit rate)*%50 (or some other awful percentage)? If the answer is yes to the above, does that mean that the next best solution would be HTB coupled with the newly updated http://www.adsl-optimizer.dk/? Ah! Thanks for pointing to us that the kernel devs finnally accepted the patches. Does someone know if the patched TC will work for kernel versions = 2.6.24? Would Shorewall with patched kernel and patched iproute2 be the most Luddite way of using adsl-optimizer? I don't use Shorewall, but rather an iptables script which works for most scenarios: http://downloads.angulosolido.pt/iptables/ If you don't use a patched kernel and if your system has only two network interfaces, you can use a script like this one: http://downloads.angulosolido.pt/QoS/HTB_shaper_basic.sh and take the overhead into account empirically (this one is HTB based). That is, start with the value the modem is synchronized for, fill the line with the average traffic you expect and lower the values until is OK. As you lower the upstream value you will find increasingly better latency values (try with ping + voip app). The best way is indeed patching the kernel and tc so that the overhead is automatically taken into account. I haven't done it yet, since that process doesn't scale for using across multiple systems of different versions. Now that the kernel patches were accepted things may change :-) Best regards Gustavo -- Angulo Sólido - Tecnologias de Informação http://angulosolido.pt ___ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
Re: [LARTC] HFSC and that ATM overhead problem (Another VOIP QoS post. Ahhhh)
On dom, 2007-11-04 at 23:04 +1100, Fog_Watch wrote: HFSC appears to be the queueing discipline of choice for VOIP. Is it? Any pointers? -- Giovanni Bajo ___ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
Re: [LARTC] HFSC and that ATM overhead problem (Another VOIP QoS post. Ahhhh)
Giovanni Bajo wrote: On dom, 2007-11-04 at 23:04 +1100, Fog_Watch wrote: HFSC appears to be the queueing discipline of choice for VOIP. Is it? Any pointers? Well, it can decouple bandwidth and delay. And both are important here. Some documentation pointers: http://linux-ip.net/articles/hfsc.en/ http://www.cs.cmu.edu/~istoica/hfsc-tr.ps.gz (deep, but good read) http://www.sonycsl.co.jp/~kjc/software/TIPS.txt (regarding implementation in *BSD) http://marc.info/?t=10779959141r=1w=2 ___ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
Re: [LARTC] HFSC and that ATM overhead problem (Another VOIP QoS post. Ahhhh)
On Sun, 04 Nov 2007 15:34:07 +0100 Giovanni Bajo [EMAIL PROTECTED] wrote: On dom, 2007-11-04 at 23:04 +1100, Fog_Watch wrote: HFSC appears to be the queueing discipline of choice for VOIP. Is it? Any pointers? I was going on gut instinct from vague information I read cruising around. Michal Soltys has given the hard references. -- Lose wait. Get Gentoo. ___ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
Re: [LARTC] HFSC and that ATM overhead problem (Another VOIP QoS post. Ahhhh)
On Sun, 4 Nov 2007 12:46:37 + Gustavo Homem [EMAIL PROTECTED] wrote: I don't use Shorewall, but rather an iptables script which works for most scenarios: No disrespect, but that sounds too scary for me. I feel more comfortable if something like Shorewall is holding my hand. That is, start with the value the modem is synchronized for, fill the line with the average traffic you expect and lower the values until is OK. As you lower the upstream value you will find increasingly better latency values (try with ping + voip app). Thanks for the explanation. doesn't scale for using across multiple systems of different versions. I didn't understand that bit. What are the systems and versions? Regards Fog_Watch. -- Lose wait. Get Gentoo. ___ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
Re: [LARTC] HFSC and that ATM overhead problem (Another VOIP QoS post. Ahhhh)
On Sunday 04 November 2007 23:16, Fog_Watch wrote: On Sun, 4 Nov 2007 12:46:37 + Gustavo Homem [EMAIL PROTECTED] wrote: I don't use Shorewall, but rather an iptables script which works for most scenarios: No disrespect, but that sounds too scary for me. I feel more comfortable if something like Shorewall is holding my hand. Takes more time the first time and less time from then on. That is, start with the value the modem is synchronized for, fill the line with the average traffic you expect and lower the values until is OK. As you lower the upstream value you will find increasingly better latency values (try with ping + voip app). Thanks for the explanation. doesn't scale for using across multiple systems of different versions. I didn't understand that bit. What are the systems and versions? If you manage multiple Linux systems with different versions you realize that patching the kernels for all, and retesting afterwards, takes quite some time. Then if you need a kernel upgrade, there you go again praying that the patches work. The point was: the gain obtained from using those patches might not compensate the time investment, on the scenarios I work with. For a single setup, or multiple identical ones, it will pay off for sure. Cheers Gustavo Regards Fog_Watch. -- Angulo Sólido - Tecnologias de Informação http://angulosolido.pt ___ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
