[LARTC] QoS on data and voice traffic

[Patrick Chan <patrick_chan@mtelnet.com>]

[-- Attachment #1: Type: text/plain, Size: 1447 bytes --]

Hi,

Sorry for asking so much questions in this mailing list.

Because I have to develop a Linux router,
there are both data and voice packets passed thru it.
The voice packets are already tagged with 0x8 in TOS field.
The bandwidth of the serial link is 115200bps.
A voice call takes up 34Kbytes bandwidth.

Now, I use the following tc config:
tc qdisc add dev ppp0 root handle 10: cbq bandwidth 112Kbit avpkt 1000
tc class add dev ppp0 parent 10:0 classid 10:100 cbq bandwidth 112Kbit rate
57Kb
it allot 1514 weight 5Kbit prio 2 maxburst 20 avpkt 1000 isolated
tc class add dev ppp0 parent 10:0 classid 10:200 cbq bandwidth 112Kbit rate
55Kb
it allot 1514 weight 5Kbit prio 8 maxburst 20 avpkt 1000 bounded
tc qdisc add dev ppp0 parent 10:100 sfq quantum 1514b perturb 15
tc qdisc add dev ppp0 parent 10:200 sfq quantum 1514b perturb 15
tc filter add dev ppp0 parent 10:0 protocol ip prio 2 u32 match ip tos 0x8
0xff
flowid 10:100
tc filter add dev ppp0 parent 10:0 protocol ip prio 8 u32 match ip tos 0x00
0xff
 flowid 10:200


10:100 is isolated and the bandwidth allocated to this class is 57Kb,
the voice packets are successfully put to class 10:100 because
I know it by tc -s qdisc
theoretically, the voice quality should be very smooth.
But the voice is not smooth, when I start to download a file.

If I turn off tc, the quality is even terrible, when download a file.



Sorry, I just learn tc for 1 month. Hope someone can help me.....

[-- Attachment #2: Type: text/html, Size: 2403 bytes --]