TP-Link 3G Router: Failover works
After the PIN constraint was removed from my Huawei stick, the TP-Link 3G Router (TL-MR3420) is now working fine in "WAN preferred" mode. Soon after I disconnected the connection to the DSL uplink, the router began setting up the Huawei E1550 stick.
This is working so flawless, I am pretty sure my parents will no longer complain about the unstable DSL link, 3G will just take over, in case it's not working and the bandwidth is ok for them.
By the way not only the failover but also the giveback is working fine, I re-connected the WAN uplink and after half a minute, my IP was matching again my DSL provider.
Using ping to a single external IP, the failover took a break of 8 packets, the giveback a break of only 2 packets, the ping was spreading ICMP once a second. But this comparison is not really fair, the UMTS stick did the full handshake whereas the WAN uplink just a DHCP request, since my DSL router on the WAN endpoint was constantly connected.
I am only wondering what a unstable DSL link can do to this router, if connectivity will constantly jump from online to offline and back... I think, that's the reason, why the lag of the failover is perhaps not that bad in this context.
And TP-Link even put a hardcopy of the GPL in the package.