Curiosity about network throughput

Recently I purchased some Intel LAN server cards off of EBay. I did not have a specific use for them but they were cheap, new, and approved for Microsoft servers. I use the standard two NIC setup on my SBS server with ISA firewall. The two card setup is recommended for the ISA firewall. Presently I use a non-approved LAN card on my SBS server to connect to the Internet though like most SBS consultants I recommend that clients follow Microsoft’s hardware recommendations. The reason I did something different then what I recommend to clients is that my Internet traffic is small and I had the card available when I was putting the server together. Frankly I did not expect any problems but unlike most clients I would have found any NIC problems far more interesting rather than catastrophic. So here I am with a couple of “good” NIC cards for my server. Hmm….

Before I decided to bust open the case I was curious how my existing NIC was doing. In particular I was real curious about my VPN throughput. So after a little searching I found a no cost utility from Ixia called Qcheck. The folks at Ixia have better tools to benchmark VPN performance but I wanted a quick test. I installed Qcheck in four places, the SBS server, a test server with direct access to the wireless access point, a desktop with a 100 Mbps connection, and a laptop with a wireless connection. I ran the software and opened up the ports in the local firewalls for Qcheck to access the network. Qcheck sends network traffic for its throughput test that is more realistic to actual application flows than Ping. It can use a couple of different protocols but I am going test the throughput using TCP. Qcheck includes endpoint software for the throughput tests. Here are my results.

  • The desktop’s throughput to the SBS server was measured at 72 Mbps. That is about what I expected.
  • The laptop’s wireless throughput using a VPN to the SBS server was 4.1 Mbps. Ugh!
  • The laptop’s wireless throughput to my test server was 11.8 Mbps. Humph!

So my tests are done. The tests are pretty close to what I expected but now I have some numbers that quantify my expectations. In the next week I will schedule some server down time and add the new network card.

One thought on “Curiosity about network throughput”

  1. Today I finally added the new network card to the server and tested the throughput. The network performance maybe a little bit better. Oh well!

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