Schneider ComBox Remote Access over DSL

Hi folks,

I'm new to the forum and maybe a little new to Schneider tech support, but a fairly knowledgeable TCP/IP networking fellow. And I'm having problems with the Conext ComBox that Schneider Tech Support so far hasn't been able to answer.

I have the Combox at a remote cabin, off-grid in southern Vermont. The cabin has DSL service, DC powered off my solar plant and works great. I have 3 working D-Link cameras and a web-relay control box that monitors the temperature (and lets me turn the heat on remotely.) These all work fine. I had a Morningstar Tristar MPPT-60 charge controller that also worked fine over the DSL line. Unlike the D-Link cameras, the MPPT controller web page was a bit slow and pokey to load, but it worked most of the time. I figured this was because the Morningstar was one of the first controllers with Ethernet and that the CPU was probably under-powered to run the web server.

I'm upgrading the inverter from a pro sine 2.0 (no remote monitoring) probably to a SW4024 and so I started by replacing the charge controller with a Schneider MPPT-60 and planned to add the inverter this spring. I added the ComBox along the way because the UI looked impressive in the demo and it seemed to be exactly what I wanted.

The unit has always worked fine on the local network when I am at the cabin. However Remote Access via DSL has been a bear. I'm no novice here. The router is setup correctly and I can get to all my other devices remotely just fine. When I initially installed the ComBox, I managed to get the login screen remotely most times and once in 100 times managed to get to the full UI too. Aware that others had this problem too (thanks wind and sun forum), I did the firmware upgrades and hoped it would improve. (like others here, I had problems upgrading to the latest firmware without a USB stick, but did manage to do so). The unit works fine on the local network, now I can't get to the UI remotely at all. Not even the login screen.

I've run some TCPDUMP's on the IP stream while trying to access the box and it sure looks like the ComBox's IP stack doesn't handle the TCP-window size of a DSL line correctly (default TCP packets are typically 1500 bytes, the combox seems to be trying for a max segment size of 1460, my other webcams seem to negotiate a 1412 size just fine. So, I'm guessing that the good folks at Schneider need to look at the TCP-stack and adjust the way they negotiate max-segment size so it can fit through a DSL line.

I've tried to relay this simple "trouble" to the schneider helpdesk without much luck. I've also suggested I'm willing to send some TCP-Dumps and my own analysis, but this seems to be beyond the helpdesk. Oh, and I've searched the ComBox setup pages for a max-segment size or MTU setting but don't think those are user adjustable.

Any folks have any ideas either how to get a real rep at Schneider or other solutions they have found to get this neat little box to work over DSL?

Many thanks,

Rob