Region : Argentina

Model : TL-MR3220

Hardware Version : V2

Firmware Version :

ISP :

Dear Sir,
I purchased TL- MR3020 a few days back and have been using it with MTNL Mumbai prepaid internet service. While configuring USB Dongle was straight forward, I am unable to connect to internet through my existing WAN connection which I have been using with a wifi router. All the settings done for MR3020 are same as in the old WIFI router. Still Mr3020 is unable to connect to my ISP. Problem appears to be in CHAP authentication, though the User name/password/Mac cloning etc. are correct. Below are a few lines from the system log for reference:

1st day 00:02:40 PPP NOTICE Standard authentication.
1st day 00:02:40 PPP INFO pppd start
1st day 00:02:40 PPP INFO sent [PADI Host-Uniq(0x00000356)]
1st day 00:02:40 PPP INFO rcvd [PADO AC-Name:Threesa AC-MAC:00:10:18:66:0d:aa]
1st day 00:02:40 PPP INFO sent [PADR Host-Uniq(0x00000356)]
1st day 00:02:40 PPP INFO rcvd [PADS sess-id(2392)]
1st day 00:02:40 PPP INFO sent [LCP Req mru=1480 magic=0xbd963196]
1st day 00:02:40 PPP INFO rcvd [LCP Req auth=chap-MD5 mru=1492 magic=0x1568b90a]
1st day 00:02:40 PPP INFO sent [LCP Ack auth=chap-MD5 mru=1492 magic=0x1568b90a]
1st day 00:02:40 PPP INFO rcvd [LCP Ack mru=1480 magic=0xbd963196]
1st day 00:02:40 PPP INFO rcvd [CHAP Challenge (ecc97222cc3d5073fb1f0f2859cdaff8), name = "Threesa"]
1st day 00:02:40 PPP INFO sent [CHAP Response (4abf699b30acbecd84ce20bbff29555b), name = "prasad"]
1st day 00:02:41 PPP INFO rcvd [CHAP Failure "bad username or password"]
1st day 00:02:41 PPP ERROR Failed to authenticate ourselves to peer
1st day 00:02:41 PPP ERROR LCP down
1st day 00:02:41 PPP WARNING LCP down

I will be thankful for guidance in this regards.

T. Prasad