How to view the optical module DDM information?

DDM (Digital Diagnostics Monitoring) is a feature that is included in optical modules, such as SFP, SFP+, QSFP, and QSFP+ transceivers. DDM provides detailed information about the optical module's performance and status, allowing network administrators to monitor and troubleshoot network issues. In this article, we will discuss how to view the optical module DDM information.

DDM Basics

Before we discuss how to view the DDM information, it is important to understand the basics of DDM. DDM provides real-time monitoring of the optical module's key parameters, such as temperature, voltage, and optical power. This information is transmitted over the module's I2C bus and can be read using a compatible host device.

DDM information can be accessed using a variety of network management tools, such as Simple Network Management Protocol (SNMP) and command-line interface (CLI) commands. The specific tools and commands used to access DDM information may vary depending on the type of optical module and the network equipment being used.

Viewing DDM Information Using SNMP

SNMP is a popular protocol used for managing and monitoring network devices. To view the DDM information using SNMP, follow these steps:

Step 1: Enable DDM on the Optical Module

Before you can view the DDM information using SNMP, you need to ensure that DDM is enabled on the optical module. DDM is typically enabled by default, but you can verify this by checking the module's datasheet or by using the appropriate CLI command.

Step 2: Discover the Optical Module

To discover the optical module using SNMP, you will need to know the module's IP address or MAC address. You can use an SNMP discovery tool, such as SolarWinds Network Performance Monitor, to automatically discover the optical module on the network.

Step 3: Configure SNMP on the Host Device

You will need to configure SNMP on the host device to be able to view the DDM information. This involves setting up SNMP community strings, which are used to authenticate SNMP requests and responses.

Step 4: Use SNMP to View DDM Information

Once the optical module has been discovered and SNMP has been configured on the host device, you can use SNMP commands to view the DDM information. The specific commands used will depend on the type of optical module and the specific information that you want to view.

For example, to view the temperature of an SFP+ optical module using SNMP, you can use the following command:

snmpwalk -v2c -c [community string] [module IP address] .1.3.6.1.4.1.9.9.91.1.1.1.1.10

This command will return the temperature in Celsius degrees.

Viewing DDM Information Using CLI Commands

CLI commands are another way to view the DDM information on an optical module. The specific commands used will depend on the type of optical module and the network equipment being used.

For example, to view the optical power levels of an SFP+ module on a Cisco switch, you can use the following command:

show interface transceiver details

This command will display the detailed information about the optical module, including the transmitter and receiver power levels.

Conclusion

DDM provides important information about the performance and status of optical modules, allowing network administrators to monitor and troubleshoot network issues. DDM information can be accessed using a variety of network management tools, such as SNMP and CLI commands. By knowing how to view the DDM information, network administrators can ensure the optimal performance and reliability of their network.