LARTC - Jan 2004 - HTB and VOIP- Choppy voice quality: What am I doing wrong? Desperate!

Hello all,

    ( I apologize if this posts twice )

    Here is my situation. I have 3 buildings linked with 100mbit fiber optics (2
runs that come to the corporate office). I have 3 RH9 boxes, one at each
location. Each box at the remote locations have 4 NICs, one for the fiber link,
one for LAN, one for the VOIP box and one for the internet connection. The
corporate office has 4 NICs also, 1 for each fiber run to the remotes, one for
the VOIP box, one for the LAN (corporate gets its internet from the remotes). I
have drawn a diagram here Http://208.45.203.98/fiber.jpg

    All of the gateways are set up properly, and I can communicate in all
directions, and can place calls clearly when the traffic is low. Now here is my
problem. When I dump a big file over the fiber link, the voice quality goes down
considerably. I hit "cancel" on the file, the quality is back. Here is
what I know about the Inter-Tel VOIP box we use: it uses UDP streams on ports
5000-5018 and 16384 @ 8-18k per side, per call, over 7 possible channels. Each
site has 7 channels, which are rarely all in use. So, the total bandwidth should
be, at max (18k x 2 directions x 7 channels) is 252k I came in on Saturday
alone, and was able to kill the quality with one call, and one 1gb file in
transit. I have set HTB up as follows:

           ( 1: )
 (1:1)             (1:2)
(1:10)       (1:11)(1:12)

Here is my script, it is the same at all 3 sites http://208.45.203.97/script.txt
(I would post it, but it is pretty long). As you can see I have given 80mbit to
the phones (remember, they should only need 252k!), 16mbit to default, and cut
windows file sharing back to 1mbit, but I still have voice issues during file
transfers! I know the filters are catching the traffic (I did "tc -s -d
class show dev eth1" and watched my numbers while calling, and transferring
files, and the incremented properly) Can anybody help me, I have been screwing
with this for days, and I am at my wits end! I am still relatively new to all of
this, but I always bite off more than I can chew :)

Dan White
Senior IT Manager 
Bookmasters Inc.

Dan White wrote:
>     All of the gateways are set up properly, and I can communicate in 
> all directions, and can place calls clearly when the traffic is low. Now 
> here is my problem. When I dump a big file over the fiber link, the 
> voice quality goes down considerably. I hit "cancel" on the file,
the
> quality is back.
Does VoIP set quality automaticaly by latency or traffic capabilities?
> Here is what I know about the Inter-Tel VOIP box we 
> use: it uses UDP streams on ports 5000-5018 and 16384 @ 8-18k per side, 
> per call, over 7 possible channels. Each site has 7 channels, which are 
> rarely all in use. So, the total bandwidth should be, at max (18k x 2 
> directions x 7 channels) is 252k I came in on Saturday alone, and was 
> able to kill the quality with one call, and one 1gb file in transit. I 
> have set HTB up as follows:
>  
>            ( 1: )
>  (1:1)             (1:2)
> (1:10)       (1:11)(1:12)
>  
> Here is my script, it is the same at all 3 sites 
> http://208.45.203.97/script.txt
You have many u32 filters. It''s not an issue, but i usualy get with fw
and
marking packets in iptables. That would make script much easier to read.
Example follows:
# $IPT -t mangle -A FORWARD -s $LAN_NET -d $ADDR -i $LAN -o $PARABOLE -j MARK
--set-mark 20
# tc filter add dev $LAN protocol ip parent 1:0 prio 1 handle 20 fw flowid 1:20
> (I would post it, but it is pretty 
> long). As you can see I have given 80mbit to the phones (remember, they 
> should only need 252k!), 16mbit to default, and cut windows file sharing 
> back to 1mbit, but I still have voice issues during file transfers! I 
> know the filters are catching the traffic (I did "tc -s -d class show 
> dev eth1" and watched my numbers while calling, and transferring
files,
> and the incremented properly).
Well, did you try assigning priorities of sending? There should be something
as prio (cosult HTB manual). If real, i don''t know "The Real
Solution", I''m
just trying to help :) I had no expierence with VoIP.


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