This MIB is an extension of the ENTITY-MIB specified in RFC2737. This MIB module contains Cisco-defined extensions to the entityPhysicalTable to represent information related to entities of class module(entPhysicalClass = 'module') which have a Processor. A processor module is defined as a physical entity that has a CPU, RAM and NVRAM so that it can independently - load a bootable image - save configuration. This module is the entry point for external applications like SNMP Manager, CLI, FTP etc. Line card is an interface card with at least a Processor and RAM. This might be referred to as Service Module in some cisco products. A configuration register is a 16 bit software register. The configuration register is mainly used to check for instructions on where to find the Cisco Operating System software. Some other functions of configuration register are: - To select a boot source and default boot filename. - To enable or disable the Break function. - To control broadcast addresses. - To set the console terminal baud rate. - To load operating software from Flash memory. - To allow us to manually boot the system using the boot command at the bootstrap program prompt. Booting is the process of initializing the hardware and starting the Operating System.