SFP vs RJ45 vs GBIC: When to Choose Which?

SFP, RJ45, and GBIC transceiver modules are three main kinds of 1GbE transceiver modules on the market. You may be puzzled by so many choices of transceiver modules. Don’t worry about it. This article will help you clarify the differences among SFP vs RJ45 vs GBIC transceivers and give you some suggestions about how to choose from them.

What Is an SFP Transceiver?

Short for small form-factor pluggable, an SFP module is a kind of fiber optic transceiver module with LC duplex interface. It supports the transmission data rate of 1GbE. SFP optical transceivers can operate on single mode or multimode fiber patch cables. The transmission distance of SFP modules ranges from 550m to 150km.

Figure1: SFP transceiver module

What Is an RJ45 Transceiver?

SFP copper RJ45 transceiver is a kind of transceiver with copper RJ45 interface. SFP copper RJ45 transceiver modules can support the transmission data rate of 1GbE. They are often used with Cat5 cables. SFP copper RJ45 transceivers are popular to be used for short distance transmission, because the overall cost of the copper network is lower compared with the optical network.

RJ45 sfp vs rj45 vs gbic

Figure2: SFP copper RJ45 transceiver module

What Is a GBIC Transceiver?

Gigabit interface converter (GBIC), is a kind of hot pluggable fiber optic transceiver module. With the data rate of 1GbE, GBIC transceiver modules can transmit data through the distance of 550m to 80km. A GBIC module supports the same data rate with an SFP module, but a GBIC transceiver module has twice the size of an SFP transceiver module.

GBIC sfp vs rj45 vs gbic

Figure3: GBIC transceiver module

SFP vs RJ45 vs GBIC: What’s the Difference?

After getting a general idea about what are SFP, RJ45, and GBIC transceivers, we will talk about the differences among them. The following chart shows the differences among SFP vs RJ45 vs GBIC transceiver modules from 4 aspects.

Transceiver module
SFP copper RJ45
LC duplex
SC duplex
Transmission distance
Cable type
Cat 5
Data rate

SFP vs RJ45 vs GBIC: When to Choose Which?

As is shown in the chart, SFP, SFP copper RJ45, and GBIC transceiver modules are all used in 1Gbit data transmission. Then when to choose which for the 1GbE network?

When to Choose SFP Transceivers?

Compared with GBIC transceiver modules, SFP modules have a smaller size. So SFP modules allow having more interfaces on a line card or a switch. Besides, SFP transceivers can support the transmission distance much longer than SFP copper RJ45 transceivers and GBIC transceivers. So if you require long transmission distance,  SFP transceivers can meet your need. Last but not least, If you already have a line card or a switch with empty SFP slots, then you need to adapt to that.

When to Choose SFP Copper RJ45 Transceivers?

When your budget is not enough to use SFP transceivers, you can choose SFP copper RJ45 transceivers for short-distance transmission. If you have the requirement of long-distance transmission afterward, you can use SFP to RJ45 slot media converters. For they can provide an economical path to extend the distance of an existing network with fiber cabling.

When to Choose GBIC Transceivers?

If you already have a line card or a switch with unoccupied GBIC slots, then you need to choose GBIC transceivers to make full use of the empty slots on your switch. In fact, GBIC transceiver modules are gradually replaced by SFP modules on the market. For SFP transceivers are regarded as the upgraded version of GBIC modules.


The differences among SFP vs RJ45 vs GBIC transceiver modules include the interface type, transmission distance, and cable type. Your choice among them depends on different situations. If you want to buy Cisco SFP modules or other transceiver modules with high quality and low cost, please contact us at sales@fs.com.

Connect Optical Transceivers of Different Brands, Fibers or Wavelengths?

Optical transceivers usually work coordinately on a pair of network switches. As switch is responsible for directing the flow of data, optical transceiver works for transforming light to data or the opposite. Then how do two transceiver modules work with each other? Can I connect two optical transceivers of different brands, fiber types or wavelengths? You can find answers here.

How Do Two Optical Transceiver Talk to Each Other?

It is known to all that the fiber optic transceiver contains a transmitter and a receiver in the same component. These are arranged in parallel so that they can operate independently from each other. When working on two switches in the same network, the transmitter on one optical transceiver takes an electrical input and converts it to an optical output from a laser diode or LED. The light from the transmitter is coupled into the fiber with a connector and is transmitted through the fiber optic cable plant. The light from the end of the fiber is coupled to a receiver on the other transceiver where a detector converts the light into an electrical signal which is then conditioned properly for use by the receiving equipment.

How optical transceiver works

Fig1. How optical transceiver works

Can I Connect Two Optical Transceivers of Different Brands, Fibers or Wavelengths?

When people are under-budgeted or in urgent need of original optical transceivers that are out of stock, they may turn to other or third-party transceivers. But how to make different transceivers work coordinately without link failure? Is it possible to connect two optical transceivers of different brands, fibers or wavelengths?

Optical Transceiver of Different Brands

As is known to all, fiber optic transceivers are manufactured with a lot of standards and protocols. If the SFP types are of the same protocol at each end, for example: both sides with SX, LX or whatever is currently in use, you can build the link between them. Please note that only the identical protocol is far more enough.

If the network switch comes from different vendors and optical transceivers with different protocols, you will get a dead link between network switch and the transceiver, thus the whole network fails. Make sure the transceiver and the switch at both ends are compatible with each other. However, as the transceiver compatibility is introduced to the optic field, many optical transceivers are now produced to be compatible with other brands. FS almost has no transceiver compatibility issues with other brand switches as all the optical transceivers have been tested to ensure its compatibility before shipping.

Optical Transceiver with Different Fiber Types

Common sense says a multimode sfp cannot work well with a single mode sfp, as the single mode fiber features a narrow core, allowing only a single mode of light to propagate while the multimode fiber has a wider core enabling multiple modes of light to propagate.

Well, as the network evolves, it is unavoidable to use single mode devices on the existing multimode fiber cables, which forces the birth of the mode conditioning cable used for single mode to multimode conversion. It is generally a duplex multimode cable that has a small length of single mode fiber at the start of the transmission length. As for optical transceiver with single mode fiber, connect the single mode connector of the cable into the transmit bore of the transceiver, and multimode connectors of the cable into the receive bore of the transceiver with all other connections going as normal.

Optical transceiver works with mode conditioning cable

Fig.2 Optical transceiver works with mode conditioning cable

Optical Transceiver on Different Wavelengths

A given transceiver generally supports a specific wavelength for both transmitting and receiving. It is vital the wavelength of the fiber optic transceivers (850nm, 1310nm, 1550nm) matches on each end, as a 1310nm sfp transceiver will not talk to a 850nm sfp transceiver. Data transmission implies that data is sent from one end to the other. The SFP transceiver on one end converts electrical signals into optical signals. A built-in laser transmits light through the fiber to the other side. Here, an optical diode converts the light back into an electrical signal. To guarantee that the SFP at the other end is capable of doing this, the SFPs at both ends should support the same wavelength.

Different wavelengths of optical transceiver
Fig.3 Different wavelengths of optical transceiver


To make sure your optical transceivers work smoothly with each other, be careful about their protocols, wavelengths and fiber types in case of link failure. FS provides a great range of fiber optic transceivers with no transceiver compatibility problem and transceiver prices are very competitive.

Comparison Between Single Mode Transceiver and Multimode Transceiver

Fiber optic transceiver is a commonly used device which can send or receive data in optical links. As the growing demand for higher speed and bandwidth, more high-speed optical transceivers like 40G QSFP+, 100G CFP and QSFP28 springs up in the market. And we cannot divide them according to data rate, but also the transmission mode—single mode transceiver and mulitmode transceiver. Then what’s the difference between them? Let’s uncover it.

Overview of Single Mode Transceiver and Multimode Transceiver

It’s known to us that fiber optic cables can be classified into single mode and multimode according to its transmission mode. It’s same to fiber optic transceiver. Single mode fiber is a type of transceiver that allows one mode to propagate. It uses single mode fiber cable to receive and transmit data, which make it suitable for longer transmission. While multimode fiber optic transceiver support multiple mode transmission, and works with multimode fiber cable which has a larger core than single mode fiber cable. It’s transmission distance is less than that of single mode fiber transceiver because of dispersion.

single mode fiber transceiver vs multimode fiber transceiver

Single Mode Transceiver Vs. Multimode Transceiver: What’s the Differences?

Since there are so many types of optical transceivers in the market, choosing which types and cabling systems to install isn’t an easy thing. Therefore, knowing the differences between them is important. Here are the differences between single mode transceiver and multimode transceiver.

Laser sources: multimode optical transceiver often uses VCSEL which offers lower manufacturing package cost when compared with edge-emitting lasers. While single mode fiber has a core diameter of 9µm, which has less tolerance to fiber core misalignment as compared to multimode fiber. Therefore, it has higher requirement and cost for lasers.

Power consumption: multimode transceivers consume less power than a single mode transceivers, which is an important consideration especially when assessing the cost of powering and cooling a data center.

Distance: the reach distance of the two types transceiver is different. The multimode optical transceivers generally have a reach of approximately 550 meters, while the single mode transceivers can get you through 10 km, 40 km, 80 km and even farther.

Speed: in telecom applications where the fiber cost is high due to long-distance data transmission, single mode transceivers can support higher speed rates with fast response time, advanced modulation formats and wavelength division multiplexing (WDM) technology.

Cost: in terms of cost, single mode transceiver are nearly two or three times higher in price when compared to multimode transceiver. Because single mode fiber cables cost more to make and are more “fragile” in nature, which makes them more expensive than multimode fiber cables.


This post gives a simple comparison between single mode transceiver and multimode transceiver. Both of them have their own advantages in data center applications. Whether you choose the single mode or multimode transceiver, it’s important to note that different optical transceivers aren’t interchangeable due to the differences in fiber core size and wavelengths. FS.COM, as a professional optical products supplier, offers various fiber optic transceiver to meet customers’ diverse needs. If you have any need, please visit www.fs.com for more detailed information.

BiDi Transceiver Overview

For several years ago, when talked about fiber optic transceiver, almost most of people engaged in telecommunication industry would tell that a transceiver is a device comprising both a transmitter and a receiver which are combined and share common circuitry. Almost all fiber optic transceivers uses two fibers to transmit data between routers and switches. One fiber is devoted to transmitting data to the networking equipment, while the other one is devoted to receiving data from the networking equipment. For recent years, a new kind of fiber optic transceiver has been available — Bi-Directional transceiver (BiDi transceiver).

BiDi Transceiver Basis

BiDi transceiver is a type of fiber optic transceiver which uses WDM (wavelength division multiplexing) bi-directional transmission technology so that it can achieve the transmission of optical channels on a fiber propagating simultaneously in both directions. BiDi transceiver is only with one port which uses an integral bidirectional coupler to transmit and receive signals over a single optical fiber (see the following picture). BiDi transceivers are specifically designed for the high-performance integrated duplex data link over a single optical fiber and used in bi-directional communication applications. The BiDi transceivers interface a network device mother board (for a switch, router or similar device) to a fiber optic or unshielded twisted pair networking cable.

BiDi transceiver

Working Principle of BiDi Transceiver

The difference between BiDi transceivers and the two-fiber optical transceiver mainly lies in that BiDi transceivers are fitted with WDM couplers, also known as diplexers, which help to combine and separate data transmitted over a single fiber based on the wavelengths of the light. So BiDi transceivers are also called WDM transceivers. BiDi transceivers are usually deployed in matched pairs to get the work most efficiently. And the diplexers of BiDi transceivers are tuned to match the expected wavelength of the transmitter and receiver that they will be transmitting data from or to.

As can be seen from the following diagram, the paired BiDi transceivers are being used to connect two devices. Device A is used to get upstream data, and Device B is used to get downstream data. Tx means transmit. Rx means receive. The diplexer in one transceiver (Device A) should have a transmitting wavelength of 1310 nm and have a receiving wavelength of 1550 nm. The diplexer in the other transceiver (Device B) should have a transmitting wavelength of 1550 nm and have a receiving wavelength of 1310 nm.

BiDi transceiver

Advantages of BiDi Transceiver

The decisive advantage of using BiDi transceiver is that it helps to reduce the cost of fiber cabling infrastructure. This is caused by reducing the number of fiber path panel ports as well as reducing the amount of tray space dedicated to fiber management. The deployment of BiDi transceiver enables the bandwidth capacity of the optical fiber to be doubled.

FS.COM BiDi Transceiver Solution

FS.COM supplies a series of BiDi transceivers with different types such as BiDi SFP. These BiDi Gigabit SFP transceivers support Fast Ethernet, Gigabit Ethernet, and Fibre Channel, etc. And they can be available for simplex SC or LC connector interface, which is used for data transmitting and receiving. Also, the BiDi SFPs are able to support a wide range of physical media from copper to long-wave single-mode optical fiber with transmission distance up to hundreds of kilometers. The most typical Tx and Rx wavelength combinations are 1310/1490 nm, 1310/1550 nm and 1490/1550 nm. FS.COM has a large selection of BiDi transceivers in stock. Choosing a FS.COM BiDi transceiver can help your fiber optic network to be most economical and efficient.

Related Article: A Brief Introduction of BiDi SFP Transceiver