General VPN Throughput Confussion - The Definitive Guide

  • According to the text in the Definitive Guide, it says that a Geode 500MHz can push 85Mbps clear text, with no VPN. It also says that the Geode and push 8.4Mbps using 3DES IPsec without the Hifn card.

    Here is my question, if I am running a 3DES IPsec tunnel on a Geode 500MHz does that choke out my 85Mps down to 8.4 total available bandwidth for all traffic, both clear and VPN? Or does it leave me with something like 76.6Mbps for clear text without VPN and 8.4 dedicated for the IPsec VPN bandwidth.

    Thank you,


  • I haven't consulted the actual text in the definitive guide but I suspect it means, as a ROUGH GUIDE: actual clear text bandwidth + 10 times 3DES IPsec bandwidth is unlikely to be any more than 85 Mbps.

    As the IPsec bandwidth increases there is less CPU available for processing clear text traffic and vice versa.

    Actual bandwidth obtained will depend on a number of other factors including frames sizes used and what else is going on in the systems (is it also serving web pages, reading the disk etc etc?)

  • Depends on what combination of traffic you have. If you have any VPN traffic it's going to lower your total possible throughput, by how much depending on how much VPN traffic you have. If you have the maximum possible VPN throughput going, you're not going to push a whole lot of traffic outside the VPN (though in reality what you'll see is more of an even split between inside VPN and outside VPN traffic, you're not going to achieve the full possible VPN throughput if you have a lot of non-VPN traffic going).