[cdmarshall]

FYI there is another thread with this same subject that existed previously.

so for the last 3 hours I have upgraded mine and pounded it hard. And haven't ran into any issues. Easy change to DD-WRT as any ASUS. Used admin upgrade page on the stock fw and started with:
http://download1.dd-wrt.com/dd-wrtv2/downloads/others/eko/BrainSlayer-V24-preSP2/2014/06-23-2014-r24461/asus-rt-ac68u/asus_rt-ac68u-firmware.trx

logged in and telnet did and nvram erase and then loaded:

http://desipro.de/ddwrt/K3-AC-Arm/25015M/dd-wrt.v24-K3_AC_ARM_STD.bin

No issues at all thus far.

It is simply VOIP calling. the T-Mobile phone firmware includes a VOIP client that connects to T-Mobiles (Level-3 actually) VOIp gateways. Sprint also has this and has for many years. T-Mobile phones will do it on any wi-fi connection. You do however have to set the address on your account for each phone as the big issues with VOIP is 911 (emergency services)

Please feel free to PM me if you with to talk further about how the TMobile and Sprint Cell VoIP works. AS I am intimately familiar with both ; )

[cdmarshall]

In the future I will only be updating the below thread as there is no need for two on the same subject.

http://www.dd-wrt.com/phpBB2/viewtopic.php?t=268581