Applying A Two-Way Bandwidth Limit - D-Link NetDefend DFL-210 User Manual

10.1.4. Pipes Basics
However, you cannot just raise the total limit to 4 Mbps and hope for the best. Why? Again, pipes
are simple things. This single pipe will not know that you mean 2 Mbps inbound and 2 Mbps out-
bound. You could just as well end up with 3 Mbps outbound and 1 Mbps inbound, since that, too,
adds up to 4 Mbps.
Normally, the right way of controlling bandwidth in both directions is to use two pipes. One for in-
bound traffic and one for outbound traffic, each set to a 2 Mbps limit.
Example 10.2. Applying a Two-Way Bandwidth Limit
This example pre-assumes that you have gone through previous example.
Create a second pipe for outbound traffic:
CLI
gw-world:/> add Pipe std-out LimitKbpsTotal=2000
Web Interface
1. Go to Traffic Management > Traffic Shaping > Pipes > Add > Pipe
2. Specify a suitable name for the pipe, for instance std-out.
3. Enter 2000 in Total textbox.
4. Click OK.
When you've created your pipe for outbound bandwidth control, you simply add it to the forward pipe chain of the
rule that you created in the previous example:
CLI
gw-world:/> set PipeRule Outbound ForwardChain=std-out
Web Interface
1. Go to Traffic Management > Traffic Shaping > PipeRules
2. Right-click on the piperule you created in the previous example and choose Edit
3. Under the Traffic Shaping tab, make std-out selected in the Forward Chain control.
4. Click OK.
This results in all outbound connections being limited to 2 Mbps in each direction, closely emulat-
ing a normal 256 kbps Internet connection.
Of course, using the same pipe in both directions is perfectly legal, if what you want is "2 Mbps
total, divided any way between forward and return data". Internet connections like these do exist,
but normally you buy the same amount of bandwidth in both directions, where data flow in one dir-
ection doesn't affect the other direction.
10.1.4.4. Using Chains to create Differentiated Limits
Now, in the previous examples, all we've done is apply a simple static traffic limit for all outbound
connections. What if we want to limit surfing further than the rest of the traffic?
Here, we could set up two "surf" pipes; inbound and outbound. However, the fact is, we most likely
won't need to limit outbound traffic a whole lot, simply because surfing usually consists of short
outbound requests followed by long inbound answers.
So, let's just set up a special "surf" pipe for inbound traffic and leave it at that:
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Chapter 10. Traffic Management