thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Networking Fundamentals · Foundational

Multimode Fiber (MMF)

Fiber with a larger core (50 or 62.5 microns) that carries multiple light paths, used for shorter distances inside buildings and data centers.

Definition

MMF uses lower-cost LED or VCSEL sources, typically at 850 nm. Grades are OM1 and OM2 (orange jacket), OM3 and OM4 (aqua, sometimes violet for OM4) and OM5 (lime green, wideband). Modal dispersion limits its distance to hundreds of meters at high speeds.

Example

10GBASE-SR over OM4 multimode reaches 400 m.

Exam tip

Multimode = larger core, shorter distance, usually orange or aqua jacket.

Don't confuse it with

Related terms