SR vs LR sfp: What's the difference?

SR and LR refer to the transmission distance and application of the SFP transceivers.
1.SR (Short Range) SFP:
· Transmission Distance: SR transceivers are designed for short-range transmission. For example, an SFP+SR transceiver typically supports distances up to 300 meters over multimode fiber.
· Application: Ideal for use within a data center or a large building where distances are relatively short. 2.LR (Long Range) SFP:
· Transmission Distance: LR transceivers are designed for long-range transmission. For example, an SFP+ LR transceiver typically supports distances up to 10 kilometers over single-mode fiber.
· Application: Ideal for use in metropolitan area networks (MANs) or in longer-distance applications within a large campus.
Note: These are typical ranges and applications. The actual transmission distance can vary based on the specific model of the transceiver and the quality of the fiber optic cable used.
 
 
SFP (Small Form-factor Pluggable) refers to a small module that can be hot-pluggable. It can be regarded as an upgraded version of GBIC. It only sizes as the thumb and can greatly increase the port density. The SFP complies with the IEEE802.3, SFF-8472 protocol and can use digital diagnostics through I2C.
10G stands for its maximum transmission rate of 10.3 Gbps. It is suitable for 10 Gigabit Ethernet. 10G optical networks have become popular in telecommunication networks. 10G switches are also being used by more and more people.
SR and LR represent the transmission distance of the optical module. SR, LR, LRM, ER and ZR are more common in the 10G IEEE standard. The transmission distance they represent is from short to long. You can check it by the following table.

10G IEEE standard	Transmission Distance
10GBASE-SR	300m or 400m
10GBASE-LR	10km
10GBASE-LRM	200m
10GBASE-ER	40km
10GBASE-ZR	80km

 

Comparison of appearance

Let us first look at the appearance of the SFP-10G-LR-S optical module and the SFP-10G-SR-S optical module. They are packaged in the form of SFP+ and can be plugged into the SFP+ port of the switch and are also hot-pluggable. The overall size is also the same. Because of different manufacturers, there are differences in the label position and interface design of the two optical modules, but the components are the same and there is no difference between them.

Name	SFP-10G-SR	SFP-10G-LR
Package type	SFP+	SFP+
Rate	10 Gbps	10 Gbps
Wavelength	850nm	1310nm
Distance（max）	300m	10km
Interface	LC duplex	LC duplex
Laser type	VCSEL 850nm	DFB 1310nm
Fiber optic type	MMF	SMF
DOM	YES	YES
Transmitted light power	-6～-1dBm	-8.2～0.5dBm
Received sensibility	< -11.1dBm	< -14.4dBm
Commercial temperature	0～ 70°C (32 ～ 158°F)	0～ 70°C (32 ～ 158°F)
Features	Maximum transmission rate 10.3Gbps 850 nm VCESL Laser Typical transmission distance 300 meters (OM3 multimode fiber) 3.3V single voltage, TTL logic interface Dual LC interface, hot-pluggable	Maximum transmission rate 10.3Gbps 1310 nm DFB-LD Laser Typical transmission distance 10 kilometers 3.3V single voltage, TTL logic interface Dual LC interface, hot-pluggable
Application range	Only used for short distance connections	Only used for long distance connections

 
 

What do SFP SR and SFP LR respectively represent?

What is SFP SR?

SFP SR stands for Small Form-factor Pluggable Short Range.
1.Transmission Distance: It is an optical transceiver module designed for short-range data communication and interconnect applications. For example, a typical SFP SR transceiver might support distances up to 550 meters over multimode fiber.
2.Application: It is commonly used for high-speed data transmissions in local area networks (LANs), data centers, and metropolitan area networks (MANs) where the transmission distances are relatively short.
3.Data Rate: SFP SR modules are available in different data rates, such as 1Gbps, 10Gbps, etc.
4.Wavelength: The typical wavelength for SFP SR transceivers is 850nm.
Note: The actual transmission distance and data rate can vary based on the specific model of the transceiver and the quality of the fiber optic cable used.
 
 

What is SFP LR?

SFP LR stands for Small Form-factor Pluggable Long Range.
1.Transmission Distance: It is an optical transceiver module designed for long-range data communication and interconnect applications. For example, a typical SFP LR transceiver might support distances up to 10 kilometers (km) over single-mode fiber.
2.Application: It is commonly used for high-speed data transmissions in wide area networks (WANs), metropolitan area networks (MANs), and in applications where the transmission distances are relatively long.
3.Data Rate: SFP LR modules are available in different data rates, such as 1Gbps, 10Gbps, etc.
4.Wavelength: The typical wavelength for SFP LR transceivers is 1310nm.
Note: The actual transmission distance and data rate can vary based on the specific model of the transceiver and the quality of the fiber optic cable used.
 
 

Do you need to buy Cisco Branded or Cisco Compatible SFP+ Modules?

So you have bought an expensive Cisco original brand switch. Now you are considering buying compatible optics for the same. But, do you really need to buy Cisco original brand modules?
Here’s a fact, not all SFP+ modules are compatible with the Cisco switch SFP+ ports. The compatibility factor must be checked before you plug the SFP+ transceivers on to the Cisco switch. Also, the SFP+ modules are critical components of fiber optic networks. That means you need a number of SFP+ modules for your network deployment. So, if you want to save costs, you would be better off with compatible third party modules. There is no point in buying a Cisco branded SFP+ module when you can get identical devices for a fraction of the price from third party sources.