OpenVPN and IPSEC Issues with Cable Modems



  • Good morning,

    I am having a bit of an issue with throughput between 3 pfSense boxes and a 4th SonicWall.  I have 3 branch offices and a main office where the 3 branch offices connect two.  Two of the branch offices are running pfSense 2.1.2 as well as the main office, and the 3rb branch office is running a SonicWal TZ105.  The pfSense box at the main office is a Hacom Jupiter with 16gb of ram and a Core i7-3630QM mobile quad core Ivy Bridge processor.  The two branch office pfSense boxes are Hacom Mercury with 8gb of ram and an Intel 2.8Ghz i3-3220T.

    The main office is serviced by a Fios 500/300 connection and also another Fios 50/50 connection and there is a backup Comcast 15/5 connection that is really out of service right now.  The 3 branch offices are connected to the internet by Optimum Online 101/35 service.  The two offices running the pfSense boxes are connected via OpenVPN and the SonicWall connects via IPSEC.

    These 3 offices are having horrendous throughput no more than 300kbit/sec over the VPN's as tested with iperf.  Without the VPN over the clear internet I can push within 10% of the given upload speed on the connections.  Now I setup a 4th IPSEC VPN from our office to the customers main office from our pfSense box and I can get within 15% of the speed over the VPN and push about 30mbit/sec across it.  If I use our Comcast cable connection and push the VPN out over that I drop down to 300kbit/second or so.  I am at a lose as to why I can't get anywhere near the speed needed over these cable connections.

    What am I missing that I need to adjust or change in order for it to function correctly?  It appears to only happen when the WAN connection is provided by cable, and occurs over two different cable providers.  Does anyone have any insight into this?

    Thank you,

    Alex