It is good but not sure how long does it take...

Limited by WR840N's NAT Throughput of WAN to LAN direction, the speed cannot be 150+. http://www.tp-link.com/en/article/?faqid=465

Firmware version of your D7? Probably it is a compatiblity issue since D7 may not use standard DLNA protocol. Try to confirm with TP-LINK support. http://www.tp-link.com/en/Support/contact/

Why you have to disable it? If you don't use IPv6, you just leave it in default settings.

bit wrote [COLOR=#000000] the IPSec feature of the router is only to implement tunnels right? Yeap.

Firmware version of your WDR4300? What kinds of phone? Have you tested on another phone? Try some suggestions in...