SNMP Overview

Yeastar S-Series VoIP PBX support SNMP (Simple Network Management Protocol). The SNMP protocol allows the network administrator to query PBX information anytime, anywhere, and monitor PBX devices in real time.

PBX requirements

The SNMP feature is supported on the following PBX models:
  • Yeastar S100 VoIP PBX
  • Yeastar S300 VoIP PBX

What is SNMP？

SNMP (Simple Network Management Protocol) is a standard network management protocol that is widely used on TCP/IP networks. The administrator can manage various network devices by a central computer, regardless of the differences in device types,vendors, and physical networks. SNMP improves administrators' work efficiency, and reduces management costs.

SNMP components

The SNMP architecture consists of 4 key components:
  • NMS (Network Management System): The NMS is a manager on a network that uses SNMP to monitor and control network devices.
  • Agent: The agent is a process running on a managed device. The agent maintains data on the managed device, responds to request packets from the NMS, and returns management data to the NMS.
  • Management object: A management object is an object to be managed on a network device. For example, management objects may include a hardware component (such as an interface board) and parameters configured for the hardware or software (such as a route selection protocol).
  • MIB (Management Information Base): MIB defines the attributes of the managed device, including the name, status, access rights, and data type of management objects.
Each managed device contains an agent process, MIB, and multiple management objects. The NMS interacts with the agent on a managed device. When receiving a command from the NMS, the agent performs operations on the MIB in the managed device.

SNMP versions

The following table shows the supported SNMP versions and details:

Version Secure Authenticate Security Description
SNMPv1 no community no Applicable to small networks with simple networking and low security requirements or small networks with good security and stability, such as campus networks and small enterprise networks.
SNMPv2c no community no

Applicable to medium and large networks with low security requirements or with good security (for example, VPN) but on which services are so busy that traffic congestion may occur.
SNMPv3 no user name no Applicable to networks of various scales, especially networks that have strict security requirements and can be managed only by authorized network administrators. For example, SNMPv3 can be used if data between the NMS and managed device needs to be transmitted over a public network.
Auth HMAC-MD5 no
Auth+Priv HMAC-MD5 CBC-DES
Note: A lack of authentication capabilities in SNMPv1 and SNMPv2c results in vulnerability to security threats, so SNMPv3 is recommended.

Basic operations of SNMP

SNMP defines the following types of operations:
  • Get: NMS retrieves variables from the managed device.
  • Set: NMS sets variables or perform an action on managed device.
  • Trap: Managed device notifies the NMS of a fault or event occurring.
Note: The Yeastar PBX only supports Get operation.

How to query PBX information

The following figure shows how to query PBX information:
  1. The NMS sends a GetRequest packet to the Agent on PBX to query the variables: sTotalCalls, sinternalCalls, etc.
  2. The Agent queries the variables information (sTotalCalls, sinternalCalls, etc.) from the MIB.
  3. The Agent sends a Response packet to the NMS.