Configure VoIP Quality of Service Settings
You can (and may need to) configure your network to improve the way it handles Asterisk VoIP traffic. This is general referred to as setting the network's Quality of Service or QOS parameters.
What can make this a necessity is if your Internet connection is shared with other users who watch YouTube videos, download music or play collaborative games over the Internet (i.e. you have kids with computers in the house). These other applications shove aside your voice packets while you are trying to hold a VoIP conversation. The result for your VoIP traffic is dropouts and garbled voice. QOS is the answer to this problem. QOS causes the router to give your VoIP traffic priority access to the Internet.
We'll have an example of QOS setting for VoIP here soon.
- Login to post comments
VoIP example from n7nmd.net
In the DD-WRT front page on your router, click on NAT/QoS and then the blue QoS blue tab that appears below it.
You can specify what service and machine gets priority on several different levels, say by IP, by netmask (group of IPs), by service type (port number) or by ethernet card (mac address).
Since I have an active Xbox user, and a couple active web users, I use a combination of these.
The priority levels for each one of the above matches is:
Exempt
Premium
Express
Standard
Bulk
Each one of these priorities is considered in order. Exempt exempts the packet from the QoS consideration queue. Bulk marks the packet at the end of the Qos queue, so that the packet will only be allowed out when the queue is empty.
Premium is used internally by DD-WRT to mark TCP control packets (icmp packets) and usually shouldn't be used for other uses, as it ends up effectively slowing down all TCP traffic for the Internet link.
In my case, I got the mac addresses of the gaming systems, and added them to the list and set them to Bulk. I also placed them on a hub and connected the hub to port 4 on the DD-WRT router. Port 4 also has Bulk precidence and is also rate-limited to 256kbps. Other machines on the network are matched by mac address, and prioritized as well.
To make sure I can surf and work from home no matter what, I increase ssh priority network wide, and make sure everything from my laptop can get out.
For asterisk use, I raised the priority of the entire machine. Further testing will show if I need to also raise the priority of the IAX2 port as well.
see http://www.n7nmd.net/dzubey/screenshot1.jpg and
http://www.n7nmd.net/dzubey/screenshot2.jpg
-Dan N7NMD