Fiber optic networks are powerful, reliable, and essential for many enterprise-level operations, but they are not easy to design, and they can prove challenging to maintain. It requires a lot of time and expertise, but both of those things cost money.If you’re looking for ways to save on network management with fiber optic systems, one bit of technology you might want to explore is digital optical monitoring.
What is Digital Optical Monitoring Mean?
Digital optical monitoring (DOM) is an interface that is designed to make diagnostics easier with fiber optic communications systems. DOM is primarily intended for use with SFP and SFP+ hardware. It’s a monitoring system that automatically tracks a number of stats in real-time. You can use those stats for monitoring and troubleshooting to ensure better and more stable communications systems.There are five key metrics that are constantly observed by DOM tools:
- Optical output power
- Optical input power
- Laser bias current
- Transceiver voltage
All of these metrics are measured at each DOM-compatible transceiver. You can look at global reports or monitor each port individually. This provides powerful real-time information that you can use for any number of tasks related to network management.
How to Use DOM
When you have DOM hardware, the monitoring systems are managed through your switch console. The specific commands and resources will depend on the manufacturer, but for Cisco systems, you can follow a standard process.
Once in your switch console, you can turn DOM on or off globally using the following commands:
Router(config)#transceiver type all
When DOM is globally enabled, you can further manage the system at each port.
When you want to view the datasheet, the #show interfaces transceiver command will tell the console to display all available information. This is how you can browse the various metrics port by port. You can find additional commands and resources via Cisco support.
Non-Cisco systems will behave similarly, but specific commands and interfaces may vary.
A Few Notes About Hardware
If you are interested in implementing DOM into your network, you will need transceivers and switches that can support it. One quick tip that can help you find DOM hardware is to look for a "D" in the name. Here's an example:
GLC-SX-MM is a transceiver that does not support DOM while GLC-SX-MMD does support DOM. The "D" at the end is the identifier, and aside from DOM support, these transceivers are perfectly identical in design and performance.
That tip can help, but it's not a universal identifier. With some model lines, the "D" moniker is not present. As an example, the SFP-10G-SR is DOM-capable, but as you can see, that isn't denoted clearly in the nomenclature.
If you want to be certain that your hardware is DOM-compatible and well-suited to the tasks at hand, you can always speak to a specialist and save a lot of time browsing catalogs.
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