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  1. Have a desire to test out various scripts for EEM before deploying to your production infrastructure; only to find that it generates more traffic then expected?
  2. Want to test out various speeds/latency/packet loss?
  3. Want to replicate multiple speeds to test a script and report on how a new process will impact the functional side?
  4. Want to replicate multiple users for a site, but lack hardware to install SMD agents to for your testing?
  • So how is this possible?

    I came across this software when working with Cisco’s Application Accelerators (Cisco WAE/WAAS), and replicated various WAN configurations and copied files over the link to evaluate how beneficial the Cisco appliance would be for the company’s network traffic.

       Info of the product at the site

     “WAN-Bridge is an open-source WAN-Emulation alternative that doesn’t require complex routing when testing the behavior of applications and network      protocols over WAN. It can run inside a virtual machine or on a standard PC. With WAN-Bridge it is easy to create fully virtualized or mixed test      environments, and benefit from advanced network monitoring and charting capabilities.”

  • How much is it going to cost me (or my company)? 

    This to can be yours for the low low price of FREE, I am referring to the software.  You may need to fork out $1 for a CD and less than $20 for a second NIC to put in the PC.  In my case my company has decommissioned desktops that I was able to snag one for testing purposes; hard drives are not required for this software to work, just RAM.

  • How hard is it to configure?

    Have you ever installed a PCI card, plugged in network/monitor/keyboard/electrical cabling?  About that hard.  Once the CD boots up (LIVE CD, even better) you will be looking at a menu system with 6 pre-configured options for various bandwidth/latency/packet loss options or provide your own settings with a ‘custom’ option.

Here is a link to the ‘How To” for additional information on the setup of the WAN simulator.  Take note that it does support having multiple clients behind the simulator and DHCP is passed through the simulator.  I suggest having DHCP complete its process before limiting yourself or make sure to use static IPs.

  • Everything comes together

So you have the simulator setup and you managed to grab a system to dedicate for the SMD agent to deploy scripts; just follow the same process as if it was in the field.  Once you confirmed it accepted the script and starts running, leave it running for an hour or two; once you have some data in Solution Manager for the test; select a WAN to simulate and review the data in a few more hours to compare the differences.

In an optimal situation, you would have a system just outside the Data center to baseline the scripts to know what kind of results you would have without the impact of the WAN or other network traffic.  This would allow you to review the baseline data and the simulated data at the same time in Solution Manager.

Wow, so this is a great document; but how am I supposed to find out the bandwidth/latency/packet loss in my environment? 

  1. Make friends with your network team and see if you have access the Network Management System (NMS); between those two sources of info you should be able to get an idea.
  2. The network team are mean/weird/unreachable.  This makes things a little more difficult, but not impossible!  If you ping an IP at the location you want to replicate the 96msec that you receive is the round trip and is the latency (this is the number to put into the simulator, ideal to use an avg).  For bandwidth most places of business rely on a “T1” (or “E1” if outside the USA); a T1 is equal to 1.544 Mbps (in the simulator you would put in a value of 1544) up and down (E1 is 2.048 Mbps).  For packet loss, keep it below .5%, as this will create chatty traffic as the nature of TCP is to keep trying until it receives acknowledgements back.
  3. Talk with folks in Accounts Payable or Finance, network connectivity is not a cheap bill; and in most cases the bill(s) have the amount of bandwidth and/or the connection type.
  • Sit back and enjoy

Once you have things going, you should have some useful reporting on scripts deployed to your production SMD agents or you need to inform the CTO/CIO how well the business processes are behaving in the field.

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