depend on TP-Link, try look for bridge/routing.
if yes, there possibility you can access the D-Link

my recommend replace TP-Link, get wireless router with QoS function

what the current address to access TP-Link & D-Link web admin
192.xxx.xxx.xxx ???

you need to change the TP-Link to 192.168.2.1
then try access yr D-Link with 192.168.1.1

Need screen shot from
Basic Settings>Network (Expand it)
Advanced Settings>Forwarding (Expand it)
Advanced Settings>IP & MAC Binding (Expand it)

even you manage get it work.

you might lost the TP-Link wireless capability. becaz D-Link will become router with (QoS).

another workaround, for wireless to work.
router behind router
1st router D-Link & 2nd router TP-Link
-internet performance degraded
-port forwarding, partial working
-QoS limited/partial working
-if you can't access to D-Link(QoS) thru TP-Link, tweaking QoS even harder.

decide yrself

Screenshot for
Basic Settings>Network>WAN (Expand it)

any chance you host yr image somewhere else(photobucket), got problem loading yesterday

select "Dynamic IP" or "802.1x + Dynamic IP."

your TP-Link need to be 192.168.2.1

when everything is done.

then try access D-Link with 192.168.1.1,

yr network will become router behind router

wish you luck

that great

next setup D-Link as router.

Need screen shot from D-Link
Device Info > WAN
Quick Setup > expand it
Advanced Setup > expand it

print screen
Advanced Setup > WAN

or else

Quick Setup > Connection type
select PPPoE > setup yr streamyx

the next thing u have to learn is how to post picture int his forum...