Just nothing type the ip address of the coustomer router in 
global configuration mode ...its enough ..it will prompt 
for authentication ..once you suplies the credentials its 
enough..

Kiran javvaji

first you Entry into MPLS Router and then fine the customer 
vrf address i.e type : sh ip vrf
you get vrf add.....then copy this add
after that type in mpls router this comm i.e
telnet (Customer ip add) /vrf vrf add )which you 
copy...then enter..you will entry you mpls router