Quality of Service Overview
Overview
The InstaGate product line now has the capability to create rules that enforce packet prioritization. These rules can be added in a variety of different ways to suit the needs of your specific network. Rules can be added based on source, destination, or service. When adding a rule you will assign a priority of high, normal or low and can choose a bandwidth limitation if necessary. Any traffic designated as high priority will be de-queued before traffic designated as normal priority. Likewise, normal priority traffic will be de-queued before traffic designated as low priority. Any traffic not defined by a specific rule will be set as normal priority by default. You may also set a bandwidth limitation on a rule by specifying a rate limit in kbps (kilobits per second).
Configuration
The Quality of Service Policies option under the Firewall menu in the web interface will allow you to add, modify or delete QoS policies. To add a policy, click Add and fill in the required fields. After naming the policy specify the source and destination networks for the policy. If you wish to apply the policy to all traffic, leave it at the default "Source Network" of 0.0.0.0/0.0.0.0 and default "Destination Network" of 0.0.0.0/0.0.0.0.
If you would like traffic to be controlled by priority select the appropriate value from the "Priority" drop-down menu. The default priority for any traffic will be normal. If you require a bandwidth limitation for a policy, fill in the "Rate Limit" field with a value in kbps (kilobits per second).
Finally, select a service for the policy to apply to. If the service is not listed you may add additional services by using the Custom Services option also located under the Firewall menu. Custom Services allows you to create a service for any port using TCP or UDP protocols.
Troubleshooting
Take caution when applying high priority and unlimited rate limit policies. If a high priority policy takes up all of the available bandwidth lower priority services will never be de-queued.
Remember that the "Rate Limit" value is in kilobits per second. Limit the bandwidth appropriately based on your total bandwidth available from your Internet service.
Verify the custom service is configured correctly. For most services the source port should be left as ANY.
Quality of Service happens on a per packet level. Remember this when troubleshooting bandwidth issues as packet size will have an impact on bandwidth usage and service levels.
