Can you access the other FreeNAS with the WAN IP address of the VR2600v? If that also won't work, you may check whether you can access the freeNAS locally and whether the virtual servers settings are...

What's the firmware version of the TD-W8961N? You may upgrade it if it is not the latest one. Also you may send an email to tplink tech support ( support.my@tp-link.com) to get help.

What's you WAN IP address? Is it a private IP or public IP? If it is a private IP, or if the IP is a reserved IP by the ISP, we cannot change it to NAT 1 probably. If it is a public one, what we can...

Sounds like an issue related to default VPI, VCI, connection type, MTU settings. Probably the profile under ADSL_3Web mismatches the info needed for your line. What's exactly the ISP's name? And what...

There is no such know issue as far as I know. You may contact tplink tech support via hotline or livechat to get help which would be faster.

For the wifi, I guess there are many interference around. So if you can, connect the TV to the AV600 via Ethernet cable. Also check the link rate with the utility as Peter suggested. BTW, what's the...