What is the difference between SFP and SFP+?

 

1.What is SFP?

SFP stands for SMALL FORM PLUGGABLE, which can be simply understood as an upgraded version of GBIC, having half the size of a GBIC module. This design significantly increases the port density of network equipment. The transmission rates of SFP modules are 155M, 1.25G, 2.5G, etc., mainly using LC interfaces. They are typically used in SONET/SDH networks, Fast Ethernet/Gigabit Ethernet, and other low-speed transmission applications.

2.What is SFP?+

While SFP+ has the same physical appearance as SFP, the transmission rates for SFP+ modules are 6G, 8G, 10G, etc. Modules that use this encapsulation include 6G/8GFC optical modules, 10G optical modules, 10G electrical modules, 10G DAC high-speed cables, and 10G AOC active optical cables. SFP+ products are mainly used in data center 10G Ethernet links.
The primary differences between SFP+ optical modules and SFP fiber modules are:

1.Transmission Speed:

SFP typically supports speeds up to 1Gbps, whereas SFP+ supports speeds up to 10Gbps, i.e., 10G Ethernet.

2.Power Consumption:

Due to the higher transmission rate of SFP+, its power consumption may be slightly increased.

3.Size:

Although SFP and SFP+ appear very similar, slight differences might affect whether they can be used in the same slot.

4.Application:

SFP is generally used for 1G network connections, like 1G Ethernet or SONET, while SFP+ is more suitable for 10G network connections.

5.Compatibility:

In most cases, SFP+ slots are backward compatible and can accept SFP modules. However, SFP slots cannot support SFP+ modules.

6.Price:

Due to technological and performance differences, SFP+ is typically more expensive than SFP. The manufacturing cost of SFP modules is higher than that of SFP+ modules.

7.Transmission Distance:

The transmission distance of SFP modules is longer than that of SFP+ modules, reaching over 120 kilometers, while SFP+ modules usually have a range within 10 kilometers.

8.Protocol Compliance:

SFP modules adhere to the IEEE802.3 and SFF-8472 standards. In contrast, SFP+ complies with IEEE 802.3ae, SFF-8431, and SFF-8432.

9.Difference and Connection:

Single-mode fiber is cheaper, but single-mode equipment is much more expensive than its multimode counterparts. Single-mode equipment can typically operate on both single-mode and multimode fibers, while multimode equipment is limited to operating on multimode fibers only. After evolving from 300Pin, XENPAK, X2, and XFP for 10G modules, SFP+ emerged, offering 10G signal transmission with the same size as SFP. By 2010, due to its compactness and cost-efficiency, SFP had replaced XFP as the mainstream in the 10G market.

10.Connection between the two:

SFP and SFP+ share the same physical dimensions. Both SFP+ and XFP are 10G fiber modules and can be interchanged with other types.

11.Tips for choosing an SFP optical module:

a. Decide on the necessary transmission distance: SFP+ modules come in different transmission distances like 150m, 300m, 10km, 40km, etc., allowing for a suitable choice based on actual application. b. Determine wavelength limitations or requirements: Different types of SFP+ modules cater to varied wavelength needs. A label on the module usually provides essential information for identifying and selecting the appropriate module.
These differences mainly stem from their technological and application distinctions. When purchasing, it's crucial to choose the right module that aligns with your equipment and requirements."

Expand knowledge:

Can I use an SFP cable on a SFP+ port?

In terms of SFP vs SFP+ compatibility, SFP+ ports often accept SFP optics but at a reduced speed of 1Gbps. Be aware, however, that you cannot plug an SFP+ transceiver into an SFP port because SFP+ does not support speeds less than 1Gbps.

Are SFP modules compatible with SFP+?

When use SFP and SFP+ modules in your network, make sure the speed of both ends of the fiber link is the same. SFP modules may can be used in SFP+ slot, but a SFP can never be connected to a SFP+ module. For their different speeds, transmission distance and wavelength.

How do I know which SFP to use?

Check your switch (or other network devices) port-supported speed and then match the correct SFP. Know your existing network cabling types. If you have a multimode fiber cabling structure, then choose the multimode SFP. If you have a single mode fiber cabling, a single mode transceiver is the only choice.

Are all SFP ports compatible?

In summary, make sure that you know what you are doing when plugging in SFP+ modules and fiber optic cables! It may look simple, but transceivers and slots are not always compatible. Always check the specs on the sticker of your transceiver/the slot, or verify the details on the manufacturer's website.