The difference of SFP 10G SR LR LRM ER and ZR

The difference of SFP 10G SR LR LRM ER and ZR

SR, LR, LRM, ER and ZR are relatively common types in the 10G IEEE standard, but what's the difference between10g sfp SR, LR, LRM, ER and ZR? To figure out, we need to know the meaning of them first.

In fiber optic communications, SR LR LRM ER and ZR are terms that stand for 10g modules transmission distance. SR means short range, LR means long range, LRM means long reach multimode , ER means extened range and ZR means ze best range. Here is the details of these five types of 10g modules.


SFP-10G-SR (Short Range) is a very common sfp module, which can links up to 300 meters in multimode fiber. In general, SR modules are almost multimode and operating in 850nm wavelength. These modules are hot-plugged can be switched out easily.


SFP-10G-LR (Long Range) is used for long-range data transmission, such as large compuses or Metro Area Network. It can be either single mode or multimode and has the advantages of low cost, low power consumption, small size and high density.


SFP-10G-LRM (Long Reach Multimode) conforms to the standard of 10gbase-lrm Ethernet, apply both traditional and new multimode optical fibers. It links with a minimum support of 220 meters on the installed multimode fiber and link with a minimum support of 300 meters on the selected multimode fiber.


SFP-10G-ER (Extened Range) supports transmission distance of up to 40 kilometers on standard Single-Mode Fiber. It is widely applied in data center and enterprise industrial park .


SFP-10G-ZR (Ze Best Range) supports transmission distance of up to 80 kilometers with 1550nm waverlength on standard Single-Mode Fiber. It compliant with SFF-8431, SFF-8432 and IEE802.3ae standard. It can be used for data networking/optical network applications.

What is the difference of Cisco S-Class Module VS Cisco Non-S-Class Module?

Technically it's hard to see any major difference between the "SFP-10G-SR-S" and "SFP-10G-SR". Both support 50micron OM3 till 300meter and we will be going with OM3. What are the technical differences as per you? Is there anything we need to factor into?

Cisco only published four 10G S-class SFP+ modules and two 40G S-class QSFP+ modules. The following table listed Cisco S-class modules. Cisco S-class modules seem to have no differences from the non-S-class modules. However, if you read the specification of these modules and the suggestions from Cisco, you will find the differences.

What is the difference of Cisco S-Class Module VS Cisco Non-S-Class Module


The standard non-S-class Cisco modules like SFP-10G-SR and SFP-10G-LR can support three protocols including Ethernet, OTN (Optical Transport Network) and WAN-PHY (Wide Area Network Physics). However, the S-class modules can only support Ethernet protocol.

Temperature Range

Compared with Cisco C-class modules which can be operating with three different temperature ranges, the Cisco S-class modules can only support the commercial temperature ranges which is 0 to 70°C (32 to 158°F).

Commercial temperature range (COM): 0 to 70°C (32 to 158°F)
Extended temperature range (EXT): -5 to 85°C (23 to 185°F)
Industrial temperature range (IND): -40 to 85°C (-40 to 185°F)

Transmission Distance

Cisco has introduced that the S-class modules are suggested to be used in enterprise network. In addition, the operating temperature range is smaller, thus, S-class module is recommended for shorter transmission distance applications compared with other standard modules.


The application range of S-class modules is narrower than that of non-S-class modules, as evidenced by Cisco QSFP-40G-SR4-S (S-Class) and Cisco QSFP-40G-LR4-S (S-Class). Cisco has specifically defined that Cisco QSFP-40G-SR4-S (S-Class) does not support 4x10G breakout connectivity. One should apply QSFP-40G-SR4 or QSFP-40G-CSR4 for such applications.


For most SMBs, it is costly to shop whatever Cisco S-class optics or non-S-class transceiver modules. The market has seen many third-party transceiver suppliers selling compatible Cisco S-class modules and non-S-class modules at affordable prices. You can look for a trusted third-party vendor for a compatible connectivity solution. Mind that the S-class optics provided by third-party vendors are often identical to the non-S-class modules with the same specifications.
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