We were using our UC320 with a wimax router/modem made by Zyxel and we had no issues related to the network only the bad Wimax reception. Now we switched to DSL and got a new modem made by D-Link. The internet access seems to be goin on and off even though if I connect directly to the modem by ethernet it is working fine. I also noticed that if I try to access the web interface of the DSL modem almost never get through (sometimes rarely I can reach it). I disabled firewall and DHCP on the modem just in case and was wondering if there is anything to do with the brand or other advice you may give us. We spent a lot of money to get the more reliable DSL service but it is of no use with the UC320.
The UC320W needs reliable Internet service to operate correctly.
Based on your comment "
"I also noticed that if I try to access the web interface of the DSL modem almost never get through (sometimes rarely I can reach it)." The issue seems to be related to your DSL service provider. Did you try some extended pings from a PC directly connected to the DSL modem to the default gateway from the DSL provider? Make sure you have consistant reliable internet access and then reconnect the UC320W.
I just entered manually the DNS of 220.127.116.11 on my computer and it is working fine now for some reason. Is there a way to enter this as the DNS server in the UC320 to use manually and not have to enter it in every PC? I can not find any information about assigning a default DNS server address on the UC320. I tried changing the default DNS in the DSL modem and it does not seem to ahve made any difference.