In the situation where you have multiple remote sites that need access to LabTutor Server ADInstruments recommends having a server hosted on the network where the LabTutor Clients are situated (i.e. individual LabTutor Server computers). In some instances however this might not be possible or practical. If this is the case then some care needs to be taken before deploying LabTutor Suite to ensure that the networks that link the remote sites to the central LabTutor Server are going to provided enough bandwidth and perform well enough to support your LabTutor setup. Due to the rich and engaging content provided LabTutor can be resource demanding on your network - it can stream high quality videos to many clients for example, and it is also important to remember that all user data and experiment content is saved to and served up from LabTutor Server.
Often you will find that the network links between remote sites and central locations (e.g. a central data center where the server is located) are slower than what a Local Area Network would be. These slower links can be highly saturated (because of the shear amount of data going over them from the remote site to the central data center) and also may have high latencies. These two factors can have a huge impact on how LabTutor will perform and the experience end-users have. Before deploying LabTutor Suite in a setup like this it is recommend that you first perform some basic network tests to get an idea of the available network bandwidth and what the network latencies are like. How you will perform these tests will vary depending on your infrastructure setup, it is advisable to seek advice from your IT department where possible. Below are some examples of how to determine network latencies and bandwidth that is available - once you have run these tests you should forward the results in the form of screenshots to your ADInstruments representative.
A simple and quick test to determine network latency would be to do a simple ping from a machine on each campus to a server on the data center. This will give us an indication of latency between the sites.
How to perform a ping test from a Windows-based PC (you should do this for all sites that will be accessing LabTutor Server in the central location):
- From a Windows machine open a command prompt
- Type ping -n 20 ipaddress where ipaddress is either the IP address or DNS name of the machine in the data center to ping
- Once the ping has run you should take a screenshot which can then be forwarded to your ADInstruments representative
It would also be desirable to get an indication of the available bandwidth available on your network at typical usage times (i.e. you should run these tests during the likely usage times for LabTutor). There are many available tools available to help you measure this metric, such as PassMark's Advanced Network Test. We are going to focus on using PassMark to run these network tests - while the application is not free, it does allow for a 30-day free trial of the software which in may cases should be sufficient.
PassMark does require some software to be installed on a machine that is located in the central location, and also on a client on the remote network. As such it is over to the user to ensure that they are happy with installing this software on their network. See here for information about the Advanced Network Test, http://www.passmark.com/products/pt_advnet.htm and here for details on Performance Test, http://www.passmark.com/products/pt.htm.
Below are the generic instructions for running a network test using PassMark Advanced Network Test:
- Download PassMark from http://www.passmark.com/products/pt.htm
- Install the software on a Windows machine in the data center to act as a server, set it to 'server' mode (Advanced >Networking) and ensure the relevant ports are open. See http://www.passmark.com/products/pt_advnet.htm for more information
- Install the same software on a Windows machine at each campus, set the mode as 'client'
- Open the test menu on each client (available from the Advanced > Networking)
- Point the test at the IP address of the server in the data center
- Run each test for a few minutes, then send the results from each site to your ADInstruments Representative.
If you decided to install LabTutor on a centralized server, you should also run a test session before going live with it. This would involve setting up the server and trying a couple of PowerLab sessions from each site.
For more information or advice please contact you ADInstruments Support Representative.