Frame-relay Discard Eligibility Bit (DE)

September 27th, 2008 Wael Osama Posted in Frame-Relay, QOS 2 Comments »

What is the DE bit ? The DE bit is used to indicate that the frame has a lower importance than other frames and should be dropped first if the network experienced congestion. How to set the DE bit? We can use a simple network to test our configuration. R1 is connected via frame-relay to [...]

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Frame-relay traffic shaping using MQC

September 27th, 2008 Wael Osama Posted in Frame-Relay, QOS No Comments »

To apply frame-relay traffic shaping using a normal map-class, the command frame-relay traffic-shaping must be applied to the main interface. This method has a pitfall; the problem is that when you apply the frame-relay traffic-shaping command to the main interface any DLCI that has no explicit map-class will be shaped to 56K by default. This [...]

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CAR – Rate limit examples

July 10th, 2008 Wael Osama Posted in QOS No Comments »

CAR is a policing mechanism used to limit the transmission rate of some traffic flow. Cisco actually recommends using MQC policing for its modularity and features, but CAR is still used widely in most operational networks for its simplicity. CAR can be used whenever you need to place a limit o­n upload/download traffic of any [...]

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Limiting non-business related applications during work hours

July 10th, 2008 Wael Osama Posted in CISCO HOW-TO, QOS, Security No Comments »

In this post we will explore how to limit or even stop your employees from using applications that are not related to the business during work hours. In the following example I am going to use HTTP as an example for unwanted applications, you can specify any type of application you would like to limit [...]

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PBR as a QOS tool

June 5th, 2008 Wael Osama Posted in QOS No Comments »

In order to apply QOS policies in your network, traffic should be classified first. There are many techniques available for packet classification. PBR is one of these techniques as discussed below. PBR can be used to match a specific flow and then apply QOS policies on it, like marking this traffic or routing the traffic [...]

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