[CentOS] OpenVPN throughput

Mon Aug 30 13:10:13 UTC 2010
drew einhorn <drew.einhorn at gmail.com>

On Mon, Aug 30, 2010 at 4:20 AM,  <J.Witvliet at mindef.nl> wrote:

> Last year i've been doing some experiments with openvpn.
> Just as the O.P. I was curious about sustainable throughput, and was disapointed about the results
> To obtain maximum resulst, i did:
> - use two rather heavy machines (HP DL380-G6, dual quad core)
> - two dedicated 10Gb-nic's
> - cross-connect both nics
> - DISABLE openvpn-debug (as it is VERY cpu expensive)
> - raise MTU to 4K
> Bottleneck was (in my case) the openvpn-process, that was running 100% on a single core,
> While network was not saturated.
> So for max throughput, it is probably strongswan (ipsec) or hw-encryption [or both]

What was the bandwidth when the cpu bottlenecked?
Were you running a single tcp connection transferring a single file?
Or, a mix of traffic with multiple tcp connections, udp traffic, etc?
I'm wondering if a more complex traffic mix would get the other cpus working,
and increase the total throughput.

Drew Einhorn

"You can see a lot by just looking."
  --  Yogi Berra