GLC-SX-MM vs GLC-SX-MMD? What’s the difference?

Some of our customers seem puzzled and are asking what’s the difference GLC-SX-MM vs GLC-SX-MMD? Witch one is right for my equipment!


Our short answer is – none! However, we will try to explain this in more detail. It’s related to changes in Cisco’s product nomenclature of their OEM transceivers and it happened long time ago – on 2012 Cisco announced End-of-Sale and End-of-Life Announcement for the Select Cisco Gigabit Ethernet SFP Modules. (This was discussed in another article – Is GLC-SX-MM EOL?).


Before that moment Cisco’s Part number for 1000Base-SX transceiver was GLC-SX-MM, but after that change they replaced this product with GLC-SX-MMD. Our guess is that at this moment Cisco introduced DDM (Digital Diagnostics Monitoring) or DOM (Digital Optical Monitoring) as standard feature in their GE SFP portfolio from that moment forward.


You could argue that GLC-SX-MM vs GLC-SX-MMD is the difference – DDM/DOM support! But we would say that all our compatible modules have DDM/DOM functionality as standard feature from beginnings of our presence in compatible transceiver market! In this particular case both compatible versions for replacing GLC-SX-MM or GLC-SX-MMD will be based on same our product – 1.25G-SFP-550D, with has DDM/DOM on board – and as a side effect, you will enjoy a great savings, so – maybe is worth to consider – Should You Buy 3rd Party SFP?


Have a suggestions, questions or comments – please, Contact Us!