1. An error code conversion method, comprising:
parsing, by a Point-to-Point Protocol over Ethernet (PPPoE) server, a PPPoE error code generated during a dialup process,
converting the PPPoE error code to an extended error code according to a PPPoE error code conversion rule table preconfigured
on the PPPoE server and transmitting the extended error code to a mobile terminal;
receiving, by the mobile terminal, the extended error code, interpreting the extended error code into a plain text according
to a PPPoE error code conversion rule table preconfigured on the mobile terminal and displaying the plain text to a user.