Polycom 3725-77601-001H manual 416

Polycom CMA System Operations Guide

Polycom recommends using a MIB browser to explore the CMA system MIB. A copy of the MIB can be downloaded from the CMA system. For more information go to “Download Polycom CMA System MIB Package” on page 422. The CMA system MIB is self-documenting including information about the purpose of specific traps and inform notifications.

It is important to note that you should understand how your SNMP management system is configured to properly configure the CMA system SNMP transport protocol requirements, SNMP version requirements, SNMP authentication requirements, and SNMP privacy requirements on the CMA system.

The CMA system supports three SNMP levels:

•Disabled—The CMA system SNMP processes are turned off.

•SNMPv2c—The CMA system implements a sub-version of SNMPv2. The key advantage of SNMPv2c is the Inform command. Unlike Traps, Informs are messages sent to the management system that must be positively acknowledged with a response message. If the management system does not reply to an Inform, the CMA system resends the Inform. SNMPv2c also has improved error handling and improved SET commands.

One drawback of SNMPv2c is that it is subject to packet sniffing of the clear text community string from the network traffic, because it does not encrypt communications between the management system and SNMP agents.

•SNMPv3—The CMA system implements the newest version of SNMP. Its primary feature is enhanced security. The contextEngineID in SNMPv3 uniquely identifies each SNMP entity. The contextEngineID is used to generate the key for authenticated messages.

The CMA system implements SNMPv3 communication with authentication and privacy (the authPriv security level as defined in the USM MIB).

—Authentication is used to ensure that traps are read by only the intended recipient. As messages are created, they are given a special key that is based on the contextEngineID of the entity. The key is shared with the intended recipient and used to receive the message.

—Privacy encrypts the SNMP message to ensure that it cannot be read by unauthorized users.

416 Polycom, Inc.