Dear list,
I have two linux boxes acting as VoIP Gateway in the following
configuration:
IP Phone ----------+ +------------------+
+------------------+ +---------------- IP Phone
|-----------eth0-| Linux BOX1
|-hdlc0----------hdlc0-| Linux BOX2 |-hdlc0-----------|
PC ----------------- -+ +------------------+
+-----------------+ +--------------- PC
The hdlc link is 64 kbps.
I tried to make a configuration in order to guarantee the bandidth of the
VoIP calls versus the data traffic between the two PCs.
I used CBQ + Prio and U32 filter. The ip Phones mark the packet with TOS
0x40. I also need the entire bandidth available for data traffic
when there are no calls.
I used the following configuration:
insmod /lib/modules/2.4.17_mvl21-sandpoint/kernel/net/sched/sch_cbq.o
insmod /lib/modules/2.4.17_mvl21-sandpoint/kernel/net/sched/sch_prio.o
insmod /lib/modules/2.4.17_mvl21-sandpoint/kernel/net/sched/cls_u32.o
tc qdisc del dev $int root
tc qdisc add dev $int root handle 1:0 cbq bandwidth $banda avpkt 1000 cell 8
tc class add dev $int parent 1:0 classid 1:1 cbq bandwidth $banda rate
$banda maxburst 20 avpkt 500
tc class add dev $int parent 1:1 classid 1:2 cbq bandwidth $banda rate
$banda_voce maxburst 20 avpkt 500
tc class add dev $int parent 1:1 classid 1:3 cbq bandwidth $banda rate
$banda_dati maxburst 1 avpkt 500
tc qdisc add dev $int parent 1:2 handle 20: prio
tc qdisc add dev $int parent 1:3 handle 30: prio
tc filter add dev $int parent 1:0 protocol ip prio 1 u32 match ip tos 0x40
0xff flowid 1:2
tc filter add dev $int parent 1:0 protocol ip prio 1 u32 match ip tos 0x00
0xff flowid 1:3
According to the test I performed, the configuration works because the VoiP
traffic has its bandwidth, however the voice quality is absolutely bad. This
occurs because
the bandidth is given in "avarage" while I need a more
"instant" bandidth.
How can I reduce the time window used to calculate the rate of the VoIP
class. Note (in the script) that I tried setting maxburst=1 for the best
effort class but had no result,
thanks for help,
P.S. any other configuration suggested for my application will be very
appreciated...
Luca Andreani
On Friday 05 September 2003 09:22, Andreani Luca wrote:> Dear list, > > I have two linux boxes acting as VoIP Gateway in the following > configuration: > > > IP Phone ----------+ +------------------+ > +------------------+ +---------------- IP Phone > > |-----------eth0-| Linux BOX1 > | > |-hdlc0----------hdlc0-| Linux BOX2 |-hdlc0-----------| > > PC ----------------- -+ +------------------+ > +-----------------+ +--------------- PC > > The hdlc link is 64 kbps. > > I tried to make a configuration in order to guarantee the bandidth of the > VoIP calls versus the data traffic between the two PCs. > I used CBQ + Prio and U32 filter. The ip Phones mark the packet with TOS > 0x40. I also need the entire bandidth available for data traffic > when there are no calls. > > I used the following configuration: > > > insmod /lib/modules/2.4.17_mvl21-sandpoint/kernel/net/sched/sch_cbq.o > > insmod /lib/modules/2.4.17_mvl21-sandpoint/kernel/net/sched/sch_prio.o > > insmod /lib/modules/2.4.17_mvl21-sandpoint/kernel/net/sched/cls_u32.o > > tc qdisc del dev $int root > > tc qdisc add dev $int root handle 1:0 cbq bandwidth $banda avpkt 1000 cell > 8 > > tc class add dev $int parent 1:0 classid 1:1 cbq bandwidth $banda rate > $banda maxburst 20 avpkt 500 > > tc class add dev $int parent 1:1 classid 1:2 cbq bandwidth $banda rate > $banda_voce maxburst 20 avpkt 500 > > tc class add dev $int parent 1:1 classid 1:3 cbq bandwidth $banda rate > $banda_dati maxburst 1 avpkt 500 > > tc qdisc add dev $int parent 1:2 handle 20: prio > > tc qdisc add dev $int parent 1:3 handle 30: prio > > tc filter add dev $int parent 1:0 protocol ip prio 1 u32 match ip tos 0x40 > 0xff flowid 1:2 > > tc filter add dev $int parent 1:0 protocol ip prio 1 u32 match ip tos 0x00 > 0xff flowid 1:3 > > > According to the test I performed, the configuration works because the VoiP > traffic has its bandwidth, however the voice quality is absolutely bad. > This occurs because > the bandidth is given in "avarage" while I need a more "instant" bandidth. > How can I reduce the time window used to calculate the rate of the VoIP > class. Note (in the script) that I tried setting maxburst=1 for the best > effort class but had no result,Check your bandwidth parameter : http://www.docum.org/stef.coene/qos/faq/cache/5.html Stef -- stef.coene@docum.org "Using Linux as bandwidth manager" http://www.docum.org/ #lartc @ irc.oftc.net _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/