About bandwidth limiting policies
Bandwidth limiting policies are separate from the Bandwidth module, see our help topic, About bandwidth management.
They are a set of policies that control your users' bandwidth usage, which prevents your internet connection from being overloaded. You might want to limit your users' bandwidth usage if you're experiencing a slow network because your users are using a lot of bandwidth, for example, streaming high definition videos. However, these bandwidth limiting policies only apply to downloads, not uploads.
Bandwidth Limiting policies are not cumulative. The Smoothwall Filter reads them from top to bottom. If the who, what, where and when match any of the top policies, it will be the only one applied. For this reason, you must place specific policies at the top, and more generic policies at the bottom of the Bandwidth limiting policies table.
Unauthenticated IPs are considered a separate user group. Anyone falling under this is matched based on the bandwidth policy for Unauthenticated IPs. Therefore, you need to specifically include this user group in a policy. We recommend that you create bandwidth limiting policies for the Unauthenticated IPs user group because it can be used to bypass the Smoothwall Filter.
The performance optimization message appears when you have more than one "Squid worker" on your system. Therefore, there is a possibility that users might receive a lower bandwidth if they go through just one "squid worker" because the bandwidth allocation is divided between the workers.
Viewing the number of squid workers
- Run a diagnostics check, see our help topic, Running functionality tests.
- Clear all of the selected tests, expand the Guardian tests view and select the Guardian computed settings and other information test.
- Click Test selected.
- The Functionality test results dialog box, under the Guardian info results section, displays the Number of workers. This is not the same as the Number of worker threads.
If you have multiple Squid workers, you can set the bandwidth limit value to be what you want.
You limit the bandwidth to 500-kilobytes per second (Kbytes/s). However, if you measure the speed for a single download, you only get 250-Kbytes/s for two workers, or 125-Kbytes/s for four workers. Over several connections (most browsers open several) and over several clients (usually one bucket is shared over several clients), you get the desired the total 500-Kbytes/s.
If you double the amount to 1000-Kbytes/s for two workers, you get 500-Kbytes/s for a single connection. However, by making multiple connections (or several clients), you can get 1000-Kbytes/s, not the 500-Kbytes/s intended.
Things to consider
Also, set all white listed web filtering policies to bypass bandwidth limiting.
After you create all your bandwidth limit policies, make sure that you clear the cache and restart the web proxy, see our help topic, Configuring the web proxy.
If you create policies for a specific user group (Who) and turn on the action option Shared between clients, the bandwidth limit is shared for the whole group. Leaving this blank means each individual user gets the configured value.
Be aware that the unit used to limit bandwidth is kilobytes per second:
- 512 Kbytes/s = 4 megabits per second (Mbps)
- 8,000 Kbytes/s = 62.5 Mbps
- 16,000 = 125 Mbps