100-490 · Question #37
Which Cisco CPAK 100GBASE module supports Multimode Fiber cable?
The correct answer is D. Cisco CPAK-100G-SR4. The Cisco CPAK-100G-SR4 module is designed to support Multimode Fiber (MMF) cable. It is specifically engineered for high-bandwidth 100G optical links and supports link lengths of up to 70 meters over OM3 and 100 meters over OM4 Multimode Fiber with MPO connectors. This module…
Question
Which Cisco CPAK 100GBASE module supports Multimode Fiber cable?
Options
- ACisco CPAK-100G-CWDM4
- BCisco CPAK-100G-LR4
- CCisco CPAK-100G-ER4L
- DCisco CPAK-100G-SR4
How the community answered
(32 responses)- A6% (2)
- B16% (5)
- C6% (2)
- D72% (23)
Explanation
The Cisco CPAK-100G-SR4 module is designed to support Multimode Fiber (MMF) cable. It is specifically engineered for high-bandwidth 100G optical links and supports link lengths of up to 70 meters over OM3 and 100 meters over OM4 Multimode Fiber with MPO connectors. This module is well-suited for short-range, high-speed data communications and data center applications where Multimode Fiber is typically used due to its ability to handle the large amount of data traffic over relatively short distances.
Topics
Community Discussion
9
Imani T.Oct 27, 2025D is your answer. The CPAK-100G-SR4 is the Short Range 4-lane module, and SR optics are always multimode fiber, full stop, while the LR4, ER4L, and CWDM4 options on that list are all single-mode fiber designed for longer distances.
Nina C.Oct 28, 2025Good answer, and worth adding for anyone studying this: SR4 specifically requires OM3 or OM4 MMF, and the exam may test that the reach differs between the two, 70 meters on OM3 versus 100 meters on OM4.
Ola B.Nov 1, 2025The SR4 is your multimode fiber module here, which makes D the pick, but if you have a spare 15 minutes just pull up a Cisco data sheet and search the fiber type column yourself because seeing "OM3/OM4 multimode" printed right there is a lot stickier than memorizing a list. The LR4 and CWDM4 both use single-mode which is why B is the trap answer people fall for when they go off vague memory of the "L means long reach" rule without connecting long reach to single-mode glass.
Anjali D.Nov 9, 2025Our group landed on D pretty fast once someone pointed out that SR4 literally tells you what you need to know, SR stands for Short Range and that designation always maps to multimode fiber, specifically OM3 or OM4, while LR4 and ER4L are both single-mode. The one that threw a couple of us off was the CWDM4 option, since coarse wavelength division multiplexing sounds like it could involve multiple fiber types, but CWDM4 is single-mode as well, just uses four different wavelengths over one SMF strand. A few people in the group felt the question could have been cleaner by specifying MMF vs. SMF directly rather than just saying "Multimode Fiber cable," since that phrasing leaves out the OM3/OM4 distinction that comes up in real deployments. Still, the answer is D, no real dispute there. Anyone else get tripped up by CWDM4 on a practice run, or did SR4 jump out at you right away?
Nina C.Nov 11, 2025CWDM4 absolutely got me on a Dion Thomas practice set last week, because I kept mentally grouping "multiplexing" with "more fiber types" until I drilled into the wavelength spacing and realized it is still just one SMF strand with four lanes, which honestly made the SR4 answer click a lot faster after that.
Nina C.Nov 24, 2025D is right, SR4 means short range, which uses multimode fiber.
Imani T.Nov 25, 2025SR4 is short range over multimode, yes, but worth flagging that the fiber type alone does not tell the whole story since SR4 runs OM3 or OM4 and the reach you get out of each is pretty different, so always check the transceiver spec sheet before assuming your existing glass will carry the full 100m.
Fatima Z.Oct 18, 2025ER4L, Extended Reach on multimode, C locks it every time.
Ola B.Oct 20, 2025Fatima, ER4L is single-mode, not multimode, so D is your answer there. Spin up a quick lab with a 100G transceiver spec sheet and you will see the SMF requirement spelled out plainly.