This article does not cite any sources. The Telecommunications Management Network is a protocol model defined by ITU-T for managing open systems in a communications network management issues pdf. It is part of the ITU-T Recommendation series M.
TMN provides a framework for achieving interconnectivity and communication across heterogeneous operations system and telecommunication networks. Mediation devices when it uses Q3 interface. These manage modern telecom networks and provide the data that is needed in the day-to-day running of a telecom network. Business management Includes the functions related to business aspects, analyzes trends and quality issues, for example, or to provide a basis for billing and other financial reports. Service management Handles services in the network: definition, administration and charging of services. This page was last edited on 26 June 2017, at 13:07. Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior.
SNMP is widely used in network management for network monitoring. Three significant versions of SNMP have been developed and deployed. SNMPv1 is the original version of the protocol. More recent versions, SNMPv2c and SNMPv3, feature improvements in performance, flexibility and security.
In typical uses of SNMP, one or more administrative computers called managers have the task of monitoring or managing a group of hosts or devices on a computer network. Each managed system executes a software component called an agent which reports information via SNMP to the manager. Managed devices exchange node-specific information with the NMSs. An agent is a network-management software module that resides on a managed device. An agent has local knowledge of management information and translates that information to or from an SNMP-specific form. A network management station executes applications that monitor and control managed devices. NMSs provide the bulk of the processing and memory resources required for network management.
One or more NMSs may exist on any managed network. SNMP agents expose management data on the managed systems as variables. The protocol also permits active management tasks, such as configuration changes, through remote modification of these variables. The variables accessible via SNMP are organized in hierarchies. SNMP itself does not define which variables a managed system should offer. Rather, SNMP uses an extensible design which allows applications to define their own hierarchies.
SNMP operates in the application layer of the Internet protocol suite. The SNMP agent receives requests on UDP port 161. Retrieval of the specified variable values is to be done as an atomic operation by the agent. A Response with current values is returned. Asynchronous notification from agent to manager. SNMP traps enable an agent to notify the management station of significant events by way of an unsolicited SNMP message. Destination addressing for traps is determined in an application-specific manner typically through trap configuration variables in the MIB.
If implemented correctly a SNMP message is discarded if the decoding of the message fails and thus malformed SNMP requests are ignored. A decoded SNMP request is then authenticated using the community string. If the authentication fails, a trap is generated indicating an authentication failure and the message is dropped. SNMPv1 and SNMPv2 use communities to establish trust between managers and agents. Most agents support three community names, one each for read-only, read-write and trap. These three community strings control different types of activities.
The read-only community reads data, such as the number of packets that have been transferred through the ports of a router. The read-write community string is allowed to also modify data values, such as the configuration of a router. In practice, SNMP implementations often support multiple versions: typically SNMPv1, SNMPv2c, and SNMPv3. SNMPv1 is widely used and is the de facto network-management protocol in the Internet community.
Version 1 has been criticized for its poor security. Authentication of clients is performed only by a “community string”, in effect a type of password, which is transmitted in cleartext. As presently specified, SNMPv2c is incompatible with SNMPv1 in two key areas: message formats and protocol operations. SNMPv2c also uses two protocol operations that are not specified in SNMPv1. An SNMPv2 NMS issues a command intended for an SNMPv1 agent. The NMS sends the SNMP message to the SNMPv2 proxy agent.