Method, apparatus and system for obtaining configuration file

Provided are a method, apparatus and system for obtaining a configuration file in data over cable services. The system comprises: a convergence device, a cable modem terminal system CMTS module and a cable modem CM. The convergence device is connected with the CM via the CMTS module, and is used for intercepting a first DHCP response message sent to the CM by a Dynamic Host Configuration Protocol DHCP server, obtaining the information of a configuration file of the CM from the first DHCP response message, sending the information of the configuration file of the CM to the CMTS module, replacing the address information of a trivial file transfer protocol TFTP server in the first DHCP response message by the address information of the convergence device, so as to form a second DHCP response message, and sending the second DHCP response message to the CM; the CM is used for sending a TFTP request message requesting the sending of the configuration file to the convergence device; and the CMTS module is used for intercepting the TFTP request message, requesting the TFTP server corresponding to the address information of the TFTP server to send the configuration file of the CM after confirming the consistency between the name of the configuration file in the TFTP request message and the name of the configuration file sent by the convergence device, and sending the received configuration file to the CM. Thus, the operating pressure of the CMTS is reduced, and the performances of the CMTS and the service issuing performance of the CM are further improved.