P. Since CMIP was a complex protocol based on OSI it took longer to be implemented. Many vendors by this time had already adopted SNMP and were not willing to migrate to CMIP, which lead to a wide acceptance of SNMP. SNMP is still the most popular telecom management protocol. The SNMP is an application layer management protocol that runs on UDP (user datagram protocol) in the transport layer. It follows the manager/agent model consisting of a manager having the management functions, an agent that is on the network element sending and receiving messages from the manager, and a database of management information. In SNMP, the manager and agent use a management Management Protocols information base (MIB) and a relatively small set of commands to exchange infor- mation. MIB is a collection of information that is organized hierarchically as a tree structure and uses a numeric tag or object identifier (OID) to distinguish each vari- able uniquely in the MIB and in SNMP messages. The SNMP messages to exchange information are: Message Explanation Get [GetRequest] This is a request from the manager to the agent, to get the value at a particular OID (object identifier). GetNext This is a request from the manager to the agent, to get [GetNextRequest] the value of the next instance in the MIB. GetNext is used to "walk" down the MIB tree. Response The agent responds with information to the manager [GetResponse] for a Get, GetNext, or Set command using the "response" command. Set [SetRequest] This is a request from the manager to the agent to set the value at a particular instance in the MIB. This is an asynchronous message from the agent to the manager to notify the occurrence of an event. Advantages of SNMP Ease of implementation of agent and manger with few interaction commands Ease of adding program variables to monitor Expandability with minimum effort for future needs due to simple design It is widely implemented and supported by most vendors Simple to setup and use Disadvantages of SNMP Initial version of SNMP had secur