Thanks you very much.
I am very happy to speak with someone about this problem, because it’s a mystery for me !
As I said this problem begins with a DIR-655 that I sold because of that...
I bought a DIR-855 and the problem occurs the same.
With other brands (A previous Belkin Vision N1, Linksys or Netgear) it worked perfect. I insist : without doing anything my wifi radio devices worked fine.
Does anyone have such wifi radio devices with DIR-655 ou DIR-855 and have this problem or not

My wifi radio devices plays music WITHOUT need of PCs. No channel specific required, it's automatic. For example in USA you can find Logitech Squeezebox Boom (that I own) (my others devices are Philips Stremium SLA2250 and Wifi Radio devices specific in Europe).
My DIR-855 as the default for channel.
5 Ghz is off (no use).
The music stops playing after a while (from 15 min to 1hour 30 min.)
The devices stop even if they are next to the router (2 meters).
Just after the music (audio stream) stops I can press play to hace it again).
I can’t find anything in the logs (or I don’t know where to look for) if you know where to look for…
I tried to disable SPI and to UDP/TCP endpoint filtering to endpoint independant which is less restrictive : the same.
Using DHCP reservation : the same.
Using DMZ : the same.
Using Guest with no key (WEP :WPA) : the same.
A question : can the DIR-855 stream audio data continuously like other routers ?
I really do appreciate your help. I dont’t know why it could be impossible to have my wifi radio devices working properly.
André.
(i apologize for my english)