I've spent may hours to play with HTB QoS settings on the firewall, but with absolutely no effect. In fact, this is normal, because the time required to let a data packet going through the ADSL line will break the voice jitter. The only right way to handle this issue is to modify the MTU on the router.
Without setting a TOS for voip, data where going through and voice was unusable. With a lowdelay (0x10) TOS set for voip, voice was going through, but data was blocked. With a lowdelay TOS and an HTB QoS on the router, data where going through slowly and voice was scambled. After many tests, an MTU of 700 did work quite well. I did loose 15% of bandwidth for data (twice more overheads), but data and voice may be used together. Those tests have been done on a 256 kbps up stream. There is a quite good explenation about this issue on Cisco's web site, and about they're LFI technology (link fragmentation and interleaving): http://www.cisco.com/warp/public/788/voice-qos/voip-mlppp.html#link_frag Jean-Chrsitophe Kumara Jayaweera a écrit : >Hello! Everybody!!, >I want to run VoIP in the same LAN (15 windows clients) which we use for >surfing the Internet. 6-7 softphones in the same client's machines is 'the >target'. My DSL is 128kbps, (I can go to 256kbps if required). So, I am told >to install some QoS's in the LAN to improve the voice quality. Frankly, I >don't know what it (QoS= Quality of Service) is. I hope you may help me >giving "Links" to read and briefing me your ideas. >Thanks to everybody in the list. >So far my success and progress are your help. >Thanks again >Kumara > >_______________________________________________ >Asterisk-Users mailing list >Asterisk-Users@lists.digium.com >http://lists.digium.com/mailman/listinfo/asterisk-users >To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > > _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
