DDM (Digital Diagnostics Monitoring) 이란?

is a technology used in SFP transceivers in order to give the end user the ability

to monitor real-time parameters of the SFPs. Such parameters include

optical output/input power,

temperature,

laser bias current,

transceiver supply voltage etc.

DOM (Digital optical monitoring) 이란?

 DOM, is familiar with the DDM function.

It is also a feature which allows you to monitor many parameters of the transceiver module in real-time.

DOM allows you to monitor

TX (transmit) and RX (receive) of the module,

그리고 input/output power, temperature, and voltage.

Network administrators can then check and ensure that the module is functioning correctly.

Obviously a SFP with DDM/DOM funstion is high-ender than one which without it.

This is why most of modern optical SFP transceivers support DDM/DOM functions according to the industry-standard SFF-8472.

RGD (rugged) SFP 란?

 You may be confused with the difference with the SFPs with “RGD” and the one without it,

or you may be interested in the “-RGD” in the product number of some SFP transceiver modules.

So, what does RGD stand for? RGD means rugged transceivers.

In fact, these are enhanced transceiver modules which have been designed for greater durability,

and can operate under more extreme conditions. Rugged transceivers may feature

enhanced ESD protection,

extended operating temperature range so that it can help eliminate field failures

without the need of costly external protection devices.

Author Note: In general, a rugged SFP can be identified by its product model, ie. -RGD.

Specific situations depend on the specific vendors.

“=” in CISCO SFP transceivers

 If you have an experience of buying Cisco SFPs, you may be confused with

the part number with “=”,

 because you can not find out the difference with the one without “=” according to the specification.

In fact, “=” is also called a “FRU” part where FRU stands for “Field Replaceable Units”.

Those are the parts that can be used as “spare” or be shipped individually to replace damaged units. But the new parts that are ordered directly from a reseller or from Cisco usually don’t come with the = sign.

Thus, if you want to buy an SFP transceiver with the “FRU” part, you should ask your vendor to ensure this function.