monitoring
infrastructure

SNMP

Also known as: Simple Network Management Protocol, SNMPv3

A standardised protocol for monitoring network devices; an NMS polls device-side SNMP agents for metric values (Get) and receives unsolicited event notifications (Trap), with an MIB defining what each device exposes.

SNMP (Simple Network Management Protocol) is how a Network Management System (NMS) sees the inside of a managed device. The device runs an SNMP agent that maintains a tree of named values (CPU, memory, port utilisation, custom application metrics) defined by a MIB (Management Information Base). The NMS performs SNMP Get to poll values and receives SNMP Trap notifications the agent pushes when events occur.

YCM supports SNMPv3 only (the version with authentication and encryption; v1 and v2c are unsupported). Version 3 with Priv mode adds HMAC-MD5 authentication and CBC-DES encryption, which an internet-exposed YCM benefits from. Yeastar publishes a YCM-specific MIB you download from the System > SNMP page and load into your NMS. Common operational use: trap on cluster server abnormalities and PBX trunk-down events so they hit your existing pager.