Traffic shaping on high saturation networks

[lpopejoy]

We have a site with a 25/25 fiber connection that experiences periods of high saturation.  The site is also leveraging a hosted phone system.  

I'm curious what this community would advise in terms of traffic shaping.  Here are the facts:

1. We have the default rules enabled
2. We do have the phones in their own VLAN.
3. the hosted system is using the standard SIP protocol, so nothing funky there.
4. Uplink stats show packet loss during high utilization (as is expected)
5. During high utilization the site has voice problems.

What can/should I do to fix this?

I've thought about artificially limiting the "non-phone" network to 20x20 this way the phones would always have 5mbps.  However, last time I tested, there wasn't a way to limit the aggregate throughput on a network - only on a "per client" level.

[ww]

Your wan1 shaper is also configured at 25/25?

Did you check with a packet capture if rtp packets are tagged with dscp 46?

Voip  problems are about the voip quality  or call setups problems?

[lpopejoy]

Voip problems are call quality, no issues with call setups, AFAIK.

Wan1 shaper is set to 25/25.

No, I have not done a packet capture, but I will do that right now.

[lpopejoy]

Yes, appears DSCP tagging is working (packet captured on Internet interface):

[ww]

Best is a seperate  voip line.

However you can try set the pc client (localnet:x.x.x.x/xx) to prio low.

And maybe set a cap of 10Mbit on the client speed to prevent one client to peek to 25Mbit

[lpopejoy]

Separate voip line is kind of a cop out isn't it?  Isn't that why we have traffic shaping for?  ...or am I just fanaticizing?  

I have done a cap of 10Mbit/client, but that still doesn't fix 3 clients from doing something at the same time.

ALSO, I just found out the real issue is that they are dropping calls, NOT audio issues.  I'm thinking this changes the picture a bit and the issue may not be QoS at all.

[PhilipDAth]

I would use a separate circuit for the VoIP line.

You can shape the OUTBOUND traffic, but you can not control the traffic being received until AFTER you have received it and it has soaked up the bandwidth on your circuit.