From mboxrd@z Thu Jan 1 00:00:00 1970 From: "James Ma" Date: Wed, 18 Dec 2002 20:51:05 +0000 Subject: [LARTC] VoIP and CBQ MIME-Version: 1 Content-Type: multipart/mixed; boundary="----=_NextPart_000_004D_01C2A6AD.462B6FC0" Message-Id: List-Id: To: lartc@vger.kernel.org This is a multi-part message in MIME format. ------=_NextPart_000_004D_01C2A6AD.462B6FC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi, All, I did some work on QoS with CBQ. Basically, I wanted to separate VoIP = traffic from other traffics and give it guarantied bandwidth. I used the = following scripts to do the work, #!/bin/sh OPTION=3D"allot 1514 maxburst 20 avpkt 1000" tc qdisc del dev eth0 root=20 tc qdisc add dev eth0 root handle 10: cbq bandwidth 10mbit avpkt 1000 tc class add dev eth0 parent 10: classid 10:2 cbq bandwidth 10mbit rate = 34kbit $OPTION prio 3 bounded tc class add dev eth0 parent 10:2 classid 10:10 cbq bandwidth 10mbit = rate 30kbit $OPTION prio 3=20 tc class add dev eth0 parent 10:2 classid 10:20 cbq bandwidth 10mbit = rate 4kbit $OPTION prio3 tc filter add dev eth0 parent 10: protocol ip prio 3 u32 match ip tos = 0x20 0xf0 flowid 10:2 tc filter add dev eth0 parent 10: protocol ip prio 3 u32 match ip dst = 0/0 flowid 10:2 tc filter add dev eth0 parent 10:2 protocol ip prio 3 u32 match ip tos = 0x20 0xf0 flowid 10:10 tc filter add dev eth0 parent 10:2 protocol ip prio 3 u32 match ip dst = 0/0 flowid 10:20 It seemed working -- when there was no VoIP traffic, a ftp link was = using all 34kbit rate. When there was VoIP traffic, the ftp rate dropped = to 17kbit (which was correct because the voice traffic was using = 17kbit). Unfortunately, the voice quality was not good. Even if without = ftp traffic, there were packets loss for voice traffic (if you count = from 1 to 20 with one handset, you miss certain figures on the other = end, they are 4, 5, 8, 9, 12, 13 etc). Any one had the same problem before? Any one can explain it? Any = parameter I should adjust to better suit this application? Another thing I noticed was, when I changed the parameters for "allot" = (ex 300) and "avpkt" (ex 500) in order to seek better setting for this = application, the CBQ stopped doing anything, so the rate was the NIC = rate instead of 34kbit. I could change "maxburst" but it didn't improve = the voice quality. Could any one tell me how to use these parameters? Thanks, James=20 ------=_NextPart_000_004D_01C2A6AD.462B6FC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Hi, All,

I did some work on QoS with CBQ. = Basically, I=20 wanted to separate VoIP traffic from other traffics and give it = guarantied=20 bandwidth. I used the following scripts to do the work,

#!/bin/sh

OPTION=3D"allot 1514 maxburst 20 avpkt 1000"

tc qdisc del dev eth0 root

tc qdisc add dev eth0 root handle 10: cbq bandwidth 10mbit avpkt = 1000

tc class add dev eth0 parent 10: classid 10:2 cbq bandwidth 10mbit = rate=20 34kbit $OPTION prio 3 bounded

tc class add dev eth0 parent 10:2 classid 10:10 cbq bandwidth 10mbit = rate=20 30kbit $OPTION prio 3

tc class add dev eth0 parent 10:2 classid 10:20 cbq bandwidth 10mbit = rate=20 4kbit $OPTION prio3

tc filter add dev eth0 parent 10: protocol ip = prio 3=20 u32 match ip tos 0x20 0xf0 flowid 10:2

tc filter add dev eth0 parent 10: protocol ip prio 3 u32 match ip dst = 0/0=20 flowid 10:2

tc filter add dev eth0 parent 10:2 protocol ip prio 3 u32 match ip = tos 0x20=20 0xf0 flowid 10:10

tc filter add dev eth0 parent 10:2 protocol ip prio 3 u32 match ip = dst 0/0=20 flowid 10:20

It=20 seemed working -- when there was no VoIP traffic, a ftp link was = using all=20 34kbit rate. When there was VoIP traffic, the ftp rate dropped to = 17kbit=20 (which was correct because the voice traffic was using 17kbit). = Unfortunately,=20 the voice quality was not good. Even if without ftp traffic, there were = packets=20 loss for voice traffic (if you count from 1 to 20 with one handset, = you=20 miss certain figures on the other end, they are 4, 5, 8, 9, 12, 13=20 etc). Any one had the same problem = before? Any one=20 can explain it? Any parameter I should adjust to better suit this=20 application? Another thing I noticed was, when = I changed=20 the parameters for "allot" (ex 300) and "avpkt" (ex 500) in order to=20 seek better setting for this application, the CBQ stopped = doing=20 anything, so the rate was the NIC rate instead of = 34kbit. I could=20 change "maxburst" but it didn't improve the voice quality. Could any one = tell me=20 how to use these parameters? Thanks, James

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