Configuring Quality of Service (QoS) across Our VPN Tunnel

Now we all get that the reason we have customer networks is to meet the needs of both applications and users effectively—well, hopefully effectively! And we also know that the blend of the Internet’s huge growth, corporate intranets that multiply like rabbits, legions of new applications that voraciously devour bandwidth, and the combined load of voice, data, plus video traffic traveling over our IP infrastructures is totally maxing them out. We basically experience all this when our networks fail to perform well—as poor performance and unprecedented unreliability.

This leads us to QoS. Believe it or not, deploying QoS is actually more secure, cost effective, even faster in today’s networking environment! This is why I’m going to show you how to configure QoS on our VPN serial link—a great place to configure QoS in a production network, by the way.

This time, I’m going to start on the R3 router. After connecting with SDM, I’ll click the Configure button and then click Quality of Service under the Tasks bar.

From here, I’ll click Launch QoS Wizard to get to the first screen of the wizard.

After clicking Next, I’ll choose the interface that I want to use as my source or outgoing port and then click Next.

From the QoS Policy Generation screen, I can create bandwidth allocation for various types of data. By default, SDM creates three QoS classes for a typical environment. You can click View Details to get more information. I clicked Next.

If the SDM gets its way, it will go ahead and enable the NBAR protocol discovery feature for this interface.

Network Based Application Recognition (NBAR) is very cool because it allows you to both accurately identify and classify your mission-critical and optimization applications— for example, ERP. And after you’ve got these applications classified, you then get to guarantee them a minimum bandwidth to use. Basically they’re policy routed, and if these mission-critical applications are classified, they can be guaranteed a minimum amount of bandwidth, policy routed, and tagged to receive special treatment.


I clicked Yes, and from the next screen, both the QoS class and value of real-time traffic and business-critical traffic are displayed.

Click Close—the configuration’s summary is shown, but it’s super long, so I’m only showing you the top of the page.

Once I clicked Finish, it uploaded the configuration to the router. In fact, it uploaded a lot—way too much for me to copy into this book! SDM is a powerful tool, and as I’ve demonstrated, it can be used really effectively for some seriously tough configurations.