Provide network diagram of what you are trying to accomplish.

We are trying to create a VPN from location A and location B, to acomplish this task we jut got a TL-ER6120 and a TL-R600VPN routers
Our office in location A, has a ADSL connection with a HUAWEI modem/router (4 MB) with a static IP assing by the ISP.
Our office in location B, has a ADSL connection with a OBSERVA modem/router (4 Mb) with a dynamic IP assing by the ISP.
According with the diagram specificied in tp-link web help, we are able to create a LAN TO LAN VPN tunnel with this two router.
In that document, they specific mention that both site must have a IP PUBLIC address, to connect the router so i did this.

1.- Put the huawei in bridge mode, and configure the PPTP protocol in the TL-ER6120 assining the public IP to the router (TL-ER6120), WORK!!!
2.- Configure the IPSEC Protocol in the router with LAN TO LAN WORK
3.- In location B, connect a LAN port of observa modem with WAN port of TL-R600VPN assigning a different IP for the lan WORK
4.- COnfigure thr IPSEC protocol in the router with LAN TO LAN WORK
VPN TUNNEL NO WORK!!!!!!!!!!!!!
with this in mind, i just asking me for the other IP PUBLIC in location B, and concluded that with out that IP, we can't make this work.
Then i read more and i find that there is a modem router TPLINK with IPSEC VPN protocols on it.(TD-W8950ND, TD-W8960N, TD-W8970, TD-W8980)
and they called VPN endpoints. I guess this endpoint are for making CLIENT-LAN VPN solution so my questions came now
Is TL-R600VPN can work as client VPN and how can i connect it??
Can i use a TL-ER6120 with PPTP as VPN server o i must have another IP address to acomplish that??
Thank you in advance

Change Movistar Observa Telecom RTA01N mode to 1483 Bridged and configure PPPoE on TL-R600VPN.
If you want an all in one adsl/IPSec router, you can accomplish the same IPSec connectivity with less hardware.
The TL-ER6120 will work as VPN PPTP Server.