"Communication Error-' Default_Screensaver5340.spx"

[dwright361@yahoo.com]

I have an error displaying on my phone that says "Communication Error-' Default_Screensaver5340.spx"

It also has "HTML App Upgrade" listed at the top.
phone is 5340 and will not fully boot up and work.
I have been seeing this in 5.1 Sp4 a lot lately.
Any ideas?

[acejavelin]

I haven't seen it on any of my SP4 systems, but you could just disable the Screen Saver app in Application Profiles... I usually just build a new one and add the Help then move all the phones to that profile. Not really a "fix" but it should get around it, the phones will not have a screen saver though, but most of my customers ask to have it disabled anyway.

[dwright361@yahoo.com]

Thanks for the input. I think this has to do with ISP filtering port traffic ,as all of these problem endpoints are going thru NAT. I had 1 that the cable modem was not bridged and was sending a private ip to the WAN port (it was doing double NAT) of the router ,After putting the modem back in bridge mode (sending public IP to the WAN port of customer router)the screen saver file was able to load& the phone fully booted up////FYI
Doug

[acejavelin]

Double NATing is usually not a problem, I have had a few phones doing that successfully, but incorrect MTU size will cause errors similar to what you are seeing. I had a CenturyLink DSL connection into a router that we had to set the MTU all the way down to 1280 in the router to work properly. That being said, if you can avoid double NATing, by all means do it!