Purchased a Huawei E173 USB 3G-modem with a SIMcard that's locked to the discount provider Tchibo in Germany; they're using the O2 network. Installed the thing in WinXP on two computers and then also in Arch Linux on one of these computers. Got the modem working without a hitch in all three systems, had good Internet access over the HSPA and UMTS nets.
Then after I'd used the surf stick in Linux, put it back into one of the WinXP computers: no more Internet access. Same in the other Windows system and in the Linux system.
In all three systems the stick was properly initialized and I was able to obtain a stable HSPA or UMTS link to the access point. But from there on the line to the Internet was dead. I was given an IP address and could ping that but I wasn't able to ping the gateway, DHCP server, DNS servers. Also couldn't ping Google or Amazon, neither their hostnames nor their IP addresses.
Called the Tchibo mobil hotline: My new Tchibo mobil account was good, there was no block on it, and I had plenty of high-speed data volume available. They also claimed there was no known UMTS connectivity problem in my area (but they're saying that may not mean much).
For at least the next 40 hrs I had no Internet access. Then I exchanged the Huawei stick at the store and installed the new one in one of the WinXP systems. Bingo, I was back on the Internet.
So what had gone wrong with the first stick/installs? Did some network settings that perhaps are stored on the stick get corrupted between setting up and using the stick in Windows and Linux? Did the SIMlocked stick get blocked by the provider or did it self-destruct after it had been used in Linux? Had there been a hardware failure of the stick? Why was the HW/SW still working fine up to the point of the access point gateway? Wrong routing info?
I'm leery now of using the new stick in Linux again (which is where I want to use it most of the time), in case I'm again cut off from the Internet. I doubt Tchibo would exchange the stick twice.
Then, researching this, I came across >200 posts by users of the O2 network all over Germany over the past few months who complained about total outages of Internet access via UMTS on their smartphones and USB modems that lasted hours, days or even weeks. They had experienced the same symptoms as I had: excellent link to the AP, an IP address had been issued to them but the connection to the Internet was completely dead but eventually reappeared.
That raises the question of whether I had perhaps fallen into an outage hole in my home town, and there really hadn't been any problem with the first stick or any of the network config settings in Windows and Linux. But is it safe to use the new stick in both OS's?
I'd appreciate your thoughts on this. Have you had similar experiences? Any suggestions about how I could troubleshoot this or dig myself out of this hole, in case I lose Internet access again with the new stick?
P.S. Can you suggest any other expert forum that may shed light on this story?