Difference between gbic and sfp

Recently, many users have been asking about whether to choose SFP or GBIC optical modules when connecting their routers or switches. Because many users are unaware of the differences between the two, it has become a difficult decision. Today, I will explain how to make the correct choice instead of blindly purchasing or procuring.
 
Generally, when customers inquire about gigabit fiber modules, we think of SFP modules, but we tend to overlook another gigabit fiber module: GBIC. Why has GBIC gradually been replaced by SFP? What is the relationship and difference between them? Let's review their development history together!

1. What are GBIC and SFP?

1.1 What is GBIC?

GBIC (Giga Bitrate Interface Converter) is the abbreviation for Gigabit Interface Converter, which was popular in the 1990s. It converts gigabit electrical signals into optical signals. It is designed to be hot-pluggable and uses SC interfaces. It is an internationally standardized interchangeable product. Gigabit switches designed with GBIC interfaces have a significant market share due to their flexibility.
 

1.2 What is SFP?

SFP stands for Small Form-Factor Pluggable and can be understood as an upgraded version of GBIC. It is half the size of GBIC, allowing for more than twice the number of ports on the same panel. It is widely used and often adopts LC interfaces. The other functions of SFP modules are similar to GBIC. Some switch manufacturers refer to SFP modules as mini-GBIC.
 

2. What are the differences between them?

2.1 Shell

The GBIC module has a larger shell, with a size twice that of the SFP module. GBIC uses SC interfaces, while SFP modules mostly use LC interfaces.
 

2.2 Switch application

Due to the interface differences between GBIC and SFP, they are used with different switches. GBIC modules are used with GBIC slots, while SFP modules are used with SFP slots.
 

2.3 Fiber connectors

People who are not frequently in contact with fiber may mistakenly assume that GBIC and SFP modules have the same fiber connectors, which is not the case. SFP modules use LC fiber connectors, while GBIC uses SC fiber connectors.
 

2.4 Market trends

In recent years, the smaller size of SFP modules has gradually replaced GBIC modules. The large size of GBIC modules occupied too much space on switches, resulting in a limited number of interfaces on switch panels. The smaller size of SFP modules helps solve this problem.
 
For example, there may be a switch panel with 48 SFP interfaces, but no panel with 48 GBIC interfaces.
 

3. Further reading on SFP and GBIC

3.1 SFP can be understood as an upgraded version of GBIC. SFP modules have half the size of GBIC modules, allowing for more than twice the number of ports on the same panel. Since SFP modules have similar functions to GBIC, some switch manufacturers call them mini-GBIC.
 
3.2 SFP modules compress the size and power consumption by placing the clock and data recovery (CDR) and electronic dispersion compensation (EDC) outside the module.
 
3.3 SFP transceivers are specified by a multivendor agreement (MSA). SFP is designed based on the GBIC interface, allowing for higher port density (number of transceivers per inch on the motherboard edge) than GBIC. Therefore, SFP is also called "mini-GBIC". Related small form-factor transceivers (SFF transceivers) are smaller than SFP modules, but SFF is soldered to the motherboard as a pin-through-hole device instead of being plugged into a slot.
 
3.4 SFP transceivers have various transmitting and receiving types, allowing users to choose appropriate transceivers for each link to achieve the optical performance based on available fiber types, such as multimode or single-mode fibers. Available optical SFP modules are generally categorized as: 850nm wavelength/550m distance MMF (SX), 1310nm wavelength/10km distance SMF (LX), 1550nm wavelength/40km distance XD, 80km distance ZX, 120km distance EX or EZX, as well as DWDM. SFP transceivers also provide copper cable interfaces, allowing devices primarily designed for fiber communication to communicate through UTP network cables. There are also CWDM and single-fiber "bidirectional" (1310/1490nm wavelength uplink/downlink) SFPs.
 
3.5 Commercial SFP transceivers can provide speeds up to 4.25 Gbps. The XFP form factor is used for 10 Gbps transceivers, and there is a new variant called "SFP+" that has a similar form factor to SFP and can transmit 10 Gbps signals. SFP, with its advantages of compact size and low cost, has met the demand for high-density optical modules since its standardization in 2002 and has replaced XFP as the mainstream in the 10 Gbps market by 2010.
 
3.6 The difference between SFP and SFP+: 10G modules have gone through the development from 300Pin, XENPAK, X2, XFP, and finally achieved the transmission of 10G signals with the same size as SFP, which is SFP+. SFP, with its small size and low cost advantages, meets the high-density requirements for optical modules in devices. From its standardization in 2002, it has become the mainstream in the 10G market, replacing XFP.
 
 

4. Advantages of SFP+ Optical Module:

4.1. SFP+ has a more compact form factor than X2 and XFP packages (same size as SFP).

4.2. Can be directly connected to the same type of XFP, X2, XENPAK.

4.3. Lower cost than XFP, X2, XENPAK products.
 
 
Generally speaking, in modern network devices, SFP modules are more common due to their advantages of suitable size, high flexibility, and high-density ports, while GBIC modules are less common. However, in some cases, choosing GBIC modules is also necessary. Here are some considerations for choosing SFP or GBIC modules:
 

Choosing SFP modules:

 
1. Need for higher port density: SFP modules are smaller in size and can be configured with more ports on the same size equipment. Therefore, if higher port density is required, SFP modules should be chosen.
 
2. Need for more flexible network architecture: SFP modules can be hot-swapped, making network architecture more flexible, easier to configure, and maintain.
 
3. Long-distance transmission requirements: SFP modules usually have more types of transmission, allowing for longer distance transmission through single-mode fiber.
 

Choosing GBIC modules:

 
1. Requirements of older devices: Due to the past widespread use of GBIC modules, some older devices may still use GBIC modules as the standard interface. In this case, GBIC modules should be chosen.
 
2. Need for higher bandwidth: GBIC modules can support higher bandwidth, so if higher bandwidth is needed, GBIC modules should be chosen.
 
In conclusion, the choice between SFP and GBIC modules mainly depends on actual needs and device compatibility.
 
 
We hope that this article will help you understand GBIC optical modules and SFP optical modules, and eliminate any doubts about which module to choose. Seesuo Communication provides various SFP optical modules, such as SFP electrical port modules, GLC-SX-MM SFP, GLC-LH-SM SFP, GLC-LH-SM-40 SFP, GLC-ZX-SM SFP, and more. You can visit the Seesuo Communication official website to view our products, and all optical modules undergo strict testing before shipment to bring you peace of mind and comfort in use.