Limiting Bandwidth In Both Directions - D-Link NetDefend DFL-210 User Manual

10.1.4. Limiting Bandwidth in Both
Directions
CLI
gw-world:/> add PipeRule ReturnChain=std-in SourceInterface=lan
Web Interface
1. Go to Traffic Management > Traffic Shaping > Pipes > Add > Pipe Rule
2. Specify a suitable name for the pipe, for instance outbound.
3. Now enter:
• Service: all_services
• Source Interface: lan
• Source Network: lannet
• Destination Interface: wan
• Destination Network: all-nets
4. Under the Traffic Shaping tab, make std-in selected in the Return Chain control.
5. Click OK
This setup limits all traffic from the outside (the Internet) to 2 megabits per second. No priorities are applied, nor
any dynamic balancing.

10.1.4. Limiting Bandwidth in Both Directions

A single pipe doesn't care which direction the traffic through it is coming from when it calculates
total throughout. Using the same pipe for both outbound and inbound traffic is allowed by
NetDefendOS but it will not neatly partition pipe limits between the two directions. The following
scenario clarifies this.
In the previous example only bandwidth in the inbound direction is limited. We chose this direction
because in most setups, it is the direction that becomes full first. Now, what if we want to limit
outbound bandwidth in the same way?
Just inserting std-in in the forward chain won't work since you probably want 2 Mbps limit for
outbound traffic to be separate from the 2 Mbps limit for inbound traffic. If we try to pass 2 Mbps of
outbound traffic through the pipe in addition to 2 Mbps of inbound traffic, it adds up to 4 Mbps.
Since the pipe limit is 2 Mbps, you'd get something close to 1 Mbps in each direction.
Raising the total pipe limit to 4 Mbps won't solve the problem since the single pipe will not know
that 2 Mbps inbound and 2 Mbps outbound was intended. 3 Mbps outbound and 1 Mbps inbound
might be the result since that also adds up to 4 Mbps.
The recommended way to control bandwidth in both directions is to use two separate pipes
one for inbound and one for outbound traffic. In the secenario under discussion each pipe would
have a 2 Mbps limit to achieve the desired result. The following example goes through the setup for
this.
Example 10.2. Limiting Bandwidth in Both Directions
Create a second pipe for outbound traffic:
CLI
SourceNetwork=lannet DestinationInterface=wan
DestinationNetwork=all-nets Service=all_services name=Outbound
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Chapter 10. Traffic Management