Lab 10.3.7.1: Optimizing ISDN Traffic Using Compression

Objective:

To optimize the ISDN traffic between the WestCoast router and the EastCoast router, using compression methods.

Scenario:

Our company has analyzed the bandwidth usage on our EastCoast to WestCoast ISDN connection. It has been found that we are using the ISDN line to the maximum. There is not enough money in the budget to upgrade the line to a PRI link, or to allow the ISDN line to be on all the time. It is our responsibility to find a way to move more information across the link in less time. Our solution: Compression.

Lab Tasks:

  1. Cable the lab as shown in the diagram.
  2. The next task is to set up the routers and ISDN connection as in previous labs:

    • Configure IGRP routing with the AS# 777. Ensure that no routing updates will be sent out of interface BRI 0.
    • Configure the enable password to be cisco.
    • Configure the correct IP addresses on each of the routers.
    • Configure the correct ISDN switch type. (National ISDN-1)
    • Configure the correct usernames and passwords of the router to be dialed.
    • Configure the dialer list to permit IP traffic.
    • Set up the correct static routes.
    • Set up the correct SPIDs on each of the routers.

    From which router prompt are SPIDs configured?

    • Make sure that the encapsulation type is PPP.
    • For security reasons, configure the authentication to be CHAP.
    • Configure the correct timeout values, and dialer map addresses.

    Don't forget the no shutdown command on the interfaces.

     

  3. Before configuring compression on the routers, test your configurations by pinging the other router. This way you are insuring that your basic configuration is correct before changing it.
  4. The next step before adding compression is to baseline how much information can flow across the link. To do this, you will need a FlukeŽ meter capable of generating network traffic and throughput tests, or some type of network testing software that is capable of measuring line throughput. Execute several tests on your ISDN network, to give you a baseline of current ISDN link performance.

    In the space below enter your findings on the current network performance.


  5. The final step is to configure compression on the WAN interface.

    WestCoast(config-if)#compress stac
    EastCoast(config-if)#compress stac

    What other types of compression are available? Hint: enter compress ?


  6. Rerun your network performance tests. In the space below enter your findings of your new network performance.









    What has changed from your baseline test?

  7. Alter your compression method to predictor and rerun your tests.

What has changed from your baseline test?

How does stac compression compare to predictor compression?