I had to configure and install one Meg@POP router at site office.
Configuration is very simple. Just WAN, LAN and Static Routing.
After all configuration was done, I can PING from router and client to SingTel Side IP and HQ side IP but not from them.
I had to reviewed simple configuration repeatedly and unable to find any wrong.
But after check the Firewall setting since this router has security feature included.
Then realized "Block WAN Request" option checkbox was checked and need to uncheck.
After I unchecked it and save, SingTel and HQ can PING to this router successfully.
So if you are having same issue like me while configuring Cisco RV215W Wireless VPN Router, just do no forget to uncheck that "Block WAN Request" and save to able to PING from outside.
Have a good time.
(Be knowledgeable, pass it on then)