Category Archives: SFP Transceiver

Can I Connect Fiber Optic Transceivers of Different Brand?


Data centers generally accommodates hundreds or even thousands of network switches, it happens when you have to connect switches from different vendors (i.e. switch X from Cisco and switch Y from HP). As the switches only fit their own brand-based fiber optic transceiver, the main issues thus falls into this: is it possible to contact two different vendor’s fiber optic transceiver module and form a viable link? The answer is yes – but you still have to take some critical aspects into account.

connect optical transceivers from different brand

Case Study: Standard of Fiber Optic Transceiver is the Key

Sometimes people have to mix switches and fiber optic transceivers, mainly because the following reasons:

  • They already have brand X and they need more switches and they shop on price. Hence different brands
  • They need to replace switches but do not have money for all and they buy brand X and plan on going to brand X completely but it takes time to get there.

There exist quite a lot standards and protocols concerning fiber optic transceiver. Although many installers are very familiar with linking different vendor’s switch, the others are still worried that the incompatibilities of two transceivers may impede the link performance. They may come across the questions like “Can I order a 1000BASE-LX transceiver from any source and it will be compatible with all others 1000BASE-LX?” or “Would a link with a Juniper 1000Base-LX and a Cisco 1000BASE-LX transceiver work?”

fiber optic transceiver

Ideally it should work. 1000BASE-LX is a standard the same way 1000BASE-T is, except that it uses fiber as the transmission medium. You’ve already known that any copper interfaces with 1000BASE-T is interoperable since they are defined by the same 1000BASE-T standards. So you can expect the same with fiber 1000BASE-LX interfaces –  which are all defined by 1000BASE-LX. While this is true on the fiber side of the system, and should be true on the thing with the fiber optic transceiver socket. In fact, you can rest assure as SFP is multi-vendor standard that specified by a multi-source agreement (MSA). And it is a popular industry format jointly developed by many network component vendors.

Further Consideration of Fiber Optic Transceivers: Protocol, Transmission Wavelength and Cable Type

Connecting SFP optical transceivers from two different vendors still have some other restriction, since SFP transceivers differs from one another in protocol, interface type and transmission distance.

Ethernet Protocol: You have to pay attention that you use fiber optical transceiver of the same protocol at each end, for example: both sides with SX, LX or whatever is currently in use. Otherwise, you have to undertake the risk of link failure.

Cable Type: The fiber optic transceivers on each end must use the same fiber type. An SFP made for multimode fiber isn’t going to work well, if it does at all, with single-mode fiber. Same applies with other multimode fiber types: although mixing various 50 um fibers (OM2 and OM4) may work OK depending on data rate and distance. As long as each end is the same fiber type, you can mix vendors and even connector types, such as SC on one end and LC on the other end.

Wavelength: It is vital the wavelength of the fiber optic transceivers (850nm, 1310nm) matches on each end, as a 1310nm transceiver will NOT talk to a 850 nm transceiver. MMF has a lot of loss, and the wrong wavelength may cause loss and degradation on the longer runs. As for SMF, you need to be even more careful about wavelengths though, especially for long distance. So, if you are on the working range, all the fiber optic transceiver will work normally.

wavelength for optical transceiver


It is hence safe to say that when connecting two fiber optic transceivers from different fiber optic transceiver manufacturers, you can expect your fiber patch cable to lead a consistent link as long as you use modules of the same Ethernet protocol, cable type and working wavelength. FS provides fully compatible optical transceivers with affordable price and decent performance. For more information, please visit

Related Article:

3rd Party Optical Transceivers vs OEM Switch Warranty

All About Compatibility: Third-Party vs Brand Optics

GLC-T vs GLC-TE vs SFP-GE-T: Which One to Choose?


GLC-T, GLC-TE and SFP-GE-T are three Cisco 1000BASE-T SFP types. All these three models SFPs can operate on standard Category 5 unshielded twisted-pair copper cabling of link lengths up to 100 m (328 ft) and support 10/100/1000 auto negotiation and Auto MDI/MDIX. So, what’s the difference between them? In this article, comparison between Cisco GLC-T vs GLC-TE vs SFP-GE-T will be provided.

GLC-T vs GLC-TE vs SFP-GE-T on Cisco switch

Specifications for GLC-T, GLC-TE and SFP-GE-T

By access to Cisco’s relative information, specifications for Cisco GLC-T, GLC-TE and SFP-GE-T are concluded in the table below:

SFP Models Description Operating Temperature Range
Cisco GLC-T 1000BASE-T SFP Copper RJ-45 100m Transceiver COM
Cisco GLC-TE 1000BASE-T SFP Copper RJ-45 100m Transceiver EXT
Cisco SFP-GE-T 1000BASE-T SFP Copper RJ-45 100m Transceiver NEBS 3 ESD EXT

From the table above, we can see that the difference between GLC-T and GLC-TE is the operating temperature range. Operating temperature range for GLC-T and GLC-TE is respectively commercial temperature range (COM) and Extended temperature range (EXT). The difference between SFP-GE-T and GLC-TE is that the SFP-GE-T has the function of NEBS 3 ESD. Then what does that mean? Let’s read the following passages.

Explanation for SFP Operating Temperature Range: COM, EXT and IND

Operating temperature range:

  • 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)
  • Storage temperature range: -40 to 85°C (-40 to 185°F)
What Does NEBS 3 ESD Mean?  

NEBS is short for Network Equipment Building System and is a set of standards for building networking equipment which can withstand a variety of environmental stresses. NEBS has three levels: Level 1, Level 2, and Level 3. Level 1 refers to cases where minimum compatibility with the environment is needed. Level 2 applies for limited operability of the product. Finally, NEBS Level 3 (NEBS 3 ESD) certification guarantees the maximum operability of the equipment. It also certifies that the equipment will perform well in harsh environmental conditions and will not interfere with other electronic devices around. NEBS Level 3 certified networking equipment is vital in mission-critical applications. SFP-GE-T with 1000BASE-T NEBS 3 ESD, that is to say, compared to GLC-T or GLC-TE it can take greater stresses with less likelihood of failure, and are therefore a bit more trustworthy in truly mission-critical applications.

Which One Should I Use: GLC-T vs GLC-TE vs SFP-GE-T

In terms of Cisco original GLC-T vs GLC-TE vs SFP-GE-T transceivers, GLC-T and SFP-GE-T will be End-of-Sale June 1, 2017 and replaced by the GLC-TE. So then you can only buy GLC-TE transceivers from Cisco. If you’re dealing directly with a company like a telecom who specifically requires NEBS compliance, they’ll let you know and you should choose SFP-GE-T. But for most of the networks, GLC-T and GLC-TE transceivers are all you’d need for Gigabit Ethernet, and they cost less as well. Fiberstore (FS.COM) provides all these three SFP modules. We are manufactured to the exact same standards as Cisco’s own brand, and come with true lifetime warranties. Every SFP module in Fiberstore was tested to ensure 100% compatibility, but only cost a small fraction of name-brand alternatives.

Related Article: Compatible SFP for Cisco 2960 Series Switches

Related Article: A Quick Overview of Cisco 1000BASE-T GLC-T SFP Copper Module

Full CWDM Mux Demux and CWDM SFP Transceivers Solutions


CWDM systems have channels at wavelengths spaced 20 nanometers (nm) apart, compared with 0.4 nm spacing for DWDM. This allows the use of low-cost, uncooled lasers for CWDM. In a typical CWDM system, laser emissions occur on full eighteen channels at eighteen defined wavelengths: 1610 nm, 1590 nm, 1570 nm, 1550 nm, 1530 nm, 1510 nm, 1490 nm, 1470 nm, 1450 nm, 1430 nm, 1410 nm, 1390 nm, 1370 nm, 1350 nm, 1330 nm, 1310 nm, 1290 nm, 1270 nm. Besides, for CWDM systems an industry standard color coding scheme is used. The latches of the CWDM SFP transceivers match the colored port indicators on the passive units therefore guaranteeing simple setup. Following color codes and wavelength are valid for CWDM.


Full CWDM Channels (18 Channels) Mux Demux Solution

The WDM system uses a multiplexer at the transmitter to combine several wavelengths together, each one carry different signal with bite-rate up to 10G and a demultiplexer at the receiver to split them apart. Both mux and demux are passive, requiring no power supply. The 18 Channels CWDM mux demux covers all channels of 1270nm to 1610nm in 20nm increments. Without replacing any infrastructure, it totally support data rates up to 180 Gbps by being completely protocol transparent. The main fields of applications are the use in SDH (STM-1, STM-4, STM-16, STM- 64), IP (Fast Ethernet, Gigabit Ethernet, 10 Gigabit) ATM and storage (1G, 2G, 4G, 8G, 10G Fibre Channel) networks. Connectors, located on the front of the CWDM mux demux modules, are labeled and use the same color-coding that is used to indicate the wavelength of the individual CWDM SFP transceivers (shown in the figure below).


When fiber availability is limited, CWDM mux demux could increase the bandwidth on the existing fiber infrastructure. By using 18ch CWDM mux demux mentioned above and the CWDM SFP transceivers, up to 180 Gbps could be supported on a fiber pair.


Full CWDM SFP Transceivers Solution

CWDM SFP transceiver is based on the SFP form factor which is a MSA standard build. The max speed of this product is 1.25G and they are also available as 2.5G and of course the popular CWDM 10G SFP transceivers. The CWDM SFP transceiver has a specific laser which emits a “color” defined in the CWDM ITU grid. The CWDM ITU grid is defined from 1270 to 1610nm and has steps of 20nm. So the available wavelength is 1270nm, 1290nm, 1310nm, 1330nm, 1350nm, 1370nm, 1390nm, 1410nm, 1430nm, 1450nm, 1470nm, 1490nm, 1510nm, 1530nm, 1550nm, 1570nm, 1590nm and C. Besides, our CWDM SFP transceivers are similarly color-coded as the CWDM mux demux to help you match the right link connection (shown in the figure below).


We can make the CWDM SFP transceivers compatible with every brand (Cisco, HP, H3C, Juniper, Huawei, Brocade, Arista). A lot of brands have vendor locking and only with the proper coding. Fiberstore is specialized in this rebranding or recoding. We have many different switches and routers in our test lab to test the coding. We also use different Optical Spectrum Analyzers to ensure the CWDM SFP transceiver is emitting the right color and has the correct power budget. The CWDM SFP transceiver is used in combination with passive CWDM mux demux, and we can provide you a complete solution and advice on which equipment fits best in your project. Please give us your project details and we will provide the most efficient and economical solution.

1270nm SFP 1290nm SFP 1310nm SFP 1330nm SFP 1350nm SFP 1370nm SFP
1390nm SFP 1410nm SFP 1430nm SFP 1450nm SFP 1470nm SFP 1490nm SFP
1510nm SFP 1530nm SFP 1550nm SFP 1570nm SFP 1590nm SFP 1610nm SFP

Can I Use SFP Transceiver in SFP+ Slot?


A common confusion about SFP and SFP+ compatibility is that if I can use the SFP module in SFP+ slot. When I connect the SFP transceiver to SFP+ transceiver, can SFP+ negotiate down to 1G? Or is it possible to use SFP+ module in the SFP port on my switch? Can SFP+ copper twinax cable can negotiate down to 1G to support SFP? Can 1G and 10G can exist in the same link? All these questions usually create a giant headache for many engineers. After looking up many relevant documentation, now I will conclusion the answers in this article.

SFP Can be Plugged into SFP+ Ports in Most Situations
I’m not sure about the specific switch model, but as a general rule of thumb, SFPs will work in SFP+ slot, but SFP+ optics do not work in SFP slots. It’s just a power availability thing. When you plug the SFP module in SFP+ port, the speed of this port is 1G not the 10G. And sometimes this port will lock the speed at 1G until you reload the switch or do some fancy set of commands. Besides, the SFP+ port usually can never support speed under 1G. That is to say, we can’t plug the 100BASE SFP in the SFP+ port. In fact, for this question, it may depend greatly on the switch models – sometimes SFPs are supported in SFP+ ports, and sometimes not. For example, almost all SFP+ ports of Cisco switch can support SFPs and many SFP+ ports of Brocade switch only support SFP+. Though it’s feasible often, it’s safer to ask your switch vendor for some information.

SFP module in SFP+ port

SFP+ Can’t Auto-negotiate Down to 1G to Support with SFP Module
To my knowledge, unlike copper SFPs which are available in 10/100/1000 auto-negotiation, optics such as SFP and SFP+ do not support auto negotiation at all. In fact, Most (95+%) SFPs and SFP+s will only run at the rated speed, no more, no less. Besides, there is no such thing as a SFP+ that does 1G on one side (towards the fiber) and then does 10G on another side (towards the unit). Though we can use SFP in SFP+ ports in many cases, that doesn’t mean a SFP+ plugged into the SFP+ slot can support 1G. In a fiber link, if we plug a SFP in the SFP+ port on one side (1G), and then plug a SFP+ in the SFP+ port on the another side (10G), this may not work! You just can’t have 10 GbE at one end and 1 GbE at the other. For this question, if you use SFP+ copper, it also can’t negotiate down to 1G.

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. 10 SFP+ only can use for 10G SFP+ port, and can never auto-negotiate to 1G.

Related Article: Can I Use the QSFP+ Optics on QSFP28 Port?

Related Article: SFP Module: What’s It and How to Choose It?

Related Article: Understanding Video SFP Transceivers

Compatible SFPs for Ubiquiti EdgeSwitch and UniFi switch


The Ubiquiti EdgeSwitch targets the Broadband / ISP / Carrier market, which offers an extensive suite of advanced layer-2 switching features and protocols, and also provides layer-3 routing capability. The UniFi switch targets the Enterprise / SMB market, which is designed for a wider IT audience, and therefore, tend to be simpler, and easier to use. Both these two types Ubiquiti switchs are supported for SFP fiber connectivity and widely used among people. However, which SFPs can I use with my EdgeSwitch or UniFi switch? This article may give the answer on ubiquiti SFP compatibility.

Which Ubiquiti EdgeSwitch Should I Use?

The EdgeSwitch offers the forwarding capacity to simultaneously process traffic on all ports at line rate without any packet loss. The EdgeSwitch provides total, non-blocking throughput. Among 8-Port model up to 10 Gbps, 16-Port model up to 18 Gbps, 24-Port model up to 26 Gbps and 48-Port model up to 70 Gbps. The following table lists the comparison between EdgeSwitch modules, according to your specific need to choose the right one.

Model Total Non-Blocking Throughput Gigabit RJ45 Ports SFP+ Ports SFP Ports Max. Power Consumption
ES- 8- 150W 10 Gbps 8 N/A 2 150W
ES- 16- 150W 18 Gbps 16 N/A 2 150W
ES- 24- 250W 26 Gbps 24 N/A 2 250W
ES- 24- 500W 26 Gbps 24 N/A 2 500W
ES- 48- 500W 70 Gbps 48 2 2 500W
ES- 48- 750W 70 Gbps 48 2 2 750W
ES- 24- LITE 26 Gbps 24 N/A 2 25W
ES- 48- LITE 70 Gbps 48 2 2 56W
ES- 12F 16 Gbps 4 N/A 12 56W
ES- 16- XG 124 Gbps 4 12 N/A 56W
EdgeMAX – Which SFPs are compatible with EdgeSwitch?

The ubnt edgeswitch provides fiber connectivity options for your growing networks. The 8, 16, and 24-port models include two SFP ports, providing up to 1 Gbps uplinks. For high-capacity uplinks, the 48-port models include two SFP and two SFP+ ports, providing uplinks of up to 10 Gbps. Take the ES‑8‑150W for example, it has 8 Gigabit RJ45 ports and 2 Gigabit SFP ports for 10G applications (shown in the figure below). For SFP ports, we should use SFP modules and fiber patch cable.

According to an article titled “Which SFPs are compatible with the EdgeSwitch?”published in Ubiquiti Help Center, the following SFP transceivers are compatible with EdgeSwitch (only listed can be found in Fiberstore here).

SFP Model Description
Cisco GLC-SX-MM 1000BASE-SX SFP 850nm 550m Transceiver
Cisco GLC-SX-MMD 1000BASE-SX SFP 850nm 550m DOM Transceiver
HP J4858C 1000BASE-SX SFP 850nm 550m DOM Transceiver
HP J4858A 1000BASE-SX SFP 850nm 550m DOM Transceiver
Cisco GLC-LH-SM 1000BASE-LX/LH SFP 1310nm 10km Transceiver
HP J4859B 1000BASE-LX SFP 1310nm 10km DOM Transceiver
HP J4859C 1000BASE-LX SFP 1310nm 10km DOM Transceiver
Cisco GLC-T 1000BASE-T SFP Copper RJ-45 100m Transceive
Cisco SFP-H10GB-CU1M 1m 10G SFP+ Passive Direct Attach Copper Twinax Cable
Brocade 10G-SFPP-TWX-0101 1m 10G SFP+ Passive Direct Attach Copper Twinax Cable
Which Ubiquiti UniFi Switch Should I Use?

The UniFi POE switch offers the forwarding capacity to simultaneously process traffic on all ports at line rate without any packet loss. For its total, non-blocking throughput, the 24port model supports up to 26 Gbps, while the 48-port model supports up to 70 Gbps. The following table lists the comparison between UniFi switch modules, according to your specific need to choose the right one.

Model Total Non-Blocking Throughput Gigabit RJ45 Ports SFP+ Ports SFP Ports Max. Power Consumption
US- 8- 150W 10 Gbps 8 N/A 2 150W
US- 16- 150W 18 Gbps 16 N/A 2 150W
US- 24- 250W 26 Gbps 24 N/A 2 250W
US- 24- 500W 26 Gbps 24 N/A 2 500W
US- 48- 500W 70 Gbps 48 2 2 500W
US- 48- 750W 70 Gbps 48 2 2 750W
UniFi – Which SFPs are compatible with UniFi Switch?

Each model includes two SFP ports for uplinks of up to 1 Gbps. The 48port model adds two SFP+ ports for high-capacity uplinks of up to 10 Gbps, so you can directly connect to a highperformance storage server or deploy a longdistance uplink to another switch. Take the US- 8- 150W for example, it has 8 Gigabit RJ45 ports and 2 Gigabit SFP ports for 10G applications (shown in the figure below). For SFP ports, we should use SFP modules and fiber patch cable.

According to an article titled “Which SFPs can I use with UniFi switch?”published in Ubiquiti Help Center, the following SFP transceivers are compatible with EdgeSwitch. Since among some SFP module types are the same as the EdgeSwitch, I only list the different SFPs here.

SFP Model Description
Fiberstore SFP-1G85-5M

Now: SFP1G-SX-85

1000BASE-SX SFP 850nm 550m DOM Transceiver
Cisco SFP-10G-SR 10GBASE-SR SFP+ 850nm 300m DOM Transceiver
Fiberstore SFP-10G85-3M


10GBASE-SR SFP+ 850nm 300m DOM IND Transceive
Ubiquiti SFP Compatibility: Ubiquiti Compatible SFPs in Fiberstore

Fiberstore (FS.COM) provides a series of Ubiquiti compatible SFP transceivers that can be used with EdgeSwitch and UniFi switch. In Ubiquiti Networks Community SFP modules compatibility section, some people tested Fiberstore SFP modules in their EdgeSwitch. As shown in the figure below, SFP1G-SX-85, SFP1G-SX-31 and SFP-10GSR-85 SFPs are working.


Related Article: 3rd Party Optical Transceivers vs OEM Switch Warranty

What Is The Difference: SFP vs SFP+


As we know, a SFP module just looks the same as the SFP+ module. And most switches can both support SFP module and SFP+ module. So, do these two modules really refer to the same one? What’s the difference between SFP vs SFP+?


SFP vs SFP+: SFP Definition
SFP stands for Small Form-factor Pluggable. It is a hot-pluggable transceiver that plugs into the SFP port of a network switch and supports SONET, Gigabit Ethernet, Fibre Channel, and other communications standards. SFP specifications are based on IEEE802.3 and SFF-8472. They are capable of supporting speeds up to 4.25 Gbps. Due to its smaller size, SFP replaces the formerly common gigabit interface converter (GBIC). Therefore SFP is also called Mini-GBIC. By choosing different SFP module, the same electrical port on the switch can connect to different fiber types (multimode or single-mode) and different wavelengths.

SFP module Cisco

SFP vs SFP+: SFP+ Definition
Since SFP supports only up to 4.25 Gbps, SFP+ that supports data rates up to 16 Gbps was later introduced. In fact, SFP+ is an enhanced version of the SFP. The SFP+ specifications are based on SFF-8431. In today’s most applications, SFP+ module usually supports 8 Gbit/s Fibre Channel, 10 Gigabit Ethernet and Optical Transport Network standard OTU2. In comparison to earlier 10 Gigabit Ethernet XENPAK or XFP modules, SFP+ module is smaller and becomes the most popular 10 Gigabit Ethernet module in the market.

SFP+ module Cisco

Review the SFP and SFP+ definition mentioned above, we can know that the main difference between SFP and SFP+ is the data rate. And due to different data rate, the applications and transmission distance is also different.

Ethernet Application

SFP (1Gbps) SFP+ (10Gbps)
1000BASE-SX SFP 850nm 550m

1000BASE-LX/LH SFP 1310nm 20km

1000BASE-EX SFP 1310nm 40km

1000BASE-ZX SFP 1550nm 80km

10GBASE-SR SFP+ 850nm 300m

10GBASE-LRM SFP+ 1310nm 220m

10GBASE-LR SFP+ 1310nm 10km

10GBASE-ER SFP+ 1550nm 40km

10GBASE-ZR SFP+ 1550nm 100km

Fiber Channel Application

SFP (2G, 4G) SFP+ (8G)

2G Fibre Channel SFP 1310nm 2km/15km/20km/40km

2G Fibre Channel SFP 1510nm 80km


4G Fibre Channel SFP 850nm 150m

4G Fibre Channel SFP 1310nm 5km/10km/15km/20km


8G Fibre Channel SFP+ 850nm 150m

8G Fibre Channel SFP+ 1310mn 10km/20km/40km

8G Fibre Channel SFP+ 1510nm 80km

SONET/SDH Application

SFP (155Mbps, 622Mbps, 2.5Gbps) SFP+ (10G)

OC-3/STM-1 1310nm 2km/15km/40km

OC-3/STM-1 1510nm 80km


OC-12/STM-4 1310nm 500m/2km/15km/40km

OC-12/STM-4 1510nm 80km


OC-48/STM-16 1310nm 2km/15km/40km

OC-48/STM-16 1510nm 80km

OC-192/STM-64 850nm 300m

OC-192/STM-64 1310nm 2km/10km/20km/40km

OC-192/STM-64 1510nm 80km

As we’ve explained the difference of SFP vs SFP+. Usually, SFP module plugs into SFP port of the switch and SFP+ module plugs into SFP+ port of the switch. But, sometimes SFP module can also be plugged into SFP+ port. Which SFP or SFP+ module should you choose all depends on your switch types. Fiberstore is a reliable SFP transceiver module manufactures, all SFP module and SFP+ module types are available in FS.COM. Besides, SFP+ cable is also provided. What’s more, the price of SFP module and SFP+ module is lower than many other manufactures. SFP test is strict in FS.COM. Matching fiber patch cable is also available.

Related Article: Compatible SFPs for Ubiquiti EdgeSwitch and UniFi switch

Related Article: SFP Module: What’s It and How to Choose It?

Related Article: Understanding Video SFP Transceivers

Differences Between SFP, BiDi SFP and Compact SFP


As we know, a common SFP transceiver is generally with two ports, one is TX port which is used to transmit the signal, and the other one is RX port which is used to receive signals. Unlike common SFP transceiver, BiDi SFP transceiver is only with one port which uses an integral WDM coupler to transmit and receive signals over a single strand fiber. In fact, the compact SFP is a 2-channel BiDi SFP, which integrates two BiDi SFPs in one SFP module. Therefore, a compact SFP is also with two ports as the common SFP.

Differences Between SFP, BiDi SFP and Compact SFP

SFP, BiDi SFP and Compact SFP Connection Methods
All SFP transceivers must be used in pairs. For common SFPs, we should connect the two SFPs which have the same wavelength together. For example, we use a 850nm SFP at one end, then we must use a 850nm SFP on the other end (shown in the figure below).

common SFP

For BiDi SFP, since it transmits and receives signals with different wavelengths, we should connect the two BiDi SFPs which have the opposite wavelength together. For example, we use a 1310nm-TX/1490nm-RX BiDi SFP at one end, then we must use a 1490nm-TX/1310nm-RX BiDi SFP on the other end (shown in the figure below).

The compact SFP (GLC-2BX-D) usually uses 1490nm to transmit signal and the 1310nm to receive signal. Therefore, the compact SFP is always connected to two 1310nm-TX/1490nm-RX BiDi SFP over two single-mode fibers (shown in the figure below).

Compact SFP

BiDi SFP and Compact SFP Applications
At present, the BiDi SFP is mostly used in FTTx deployment P2P (point-to-point) connection. A FTTH/FTTB active Ethernet network consists of a central office (CO) connecting to the customer premises equipment (CPE). Active Ethernet networks use a P2P architecture in which each end customer is connected to the CO on a dedicated fiber. BiDi SFP allows a bi-directional communication on a single fiber by using wavelength multiplexing (WDM), which makes CO and CPE connection more simple. Compact SFP enormously increases CO port density by combining two single fiber transceivers into one SFP form factor. In addition, the compact SFP will significantly reduce the overall power consumption at the CO side.

Compact SFP FTTx

FS.COM BiDi and Compact SFP Sloutions
FS.COM provides a variety of BiDi SFPs. They can support different data rate and support transmission distance up to max 120 km that can meet the demands of today’s fiber services for carriers and enterprises.

FS SKU# Description
SKU00686G 1000BASE-BX SFP 1310nm-TX/1490nm-RX 10km Transceiver
SKU00687G 1000BASE-BX SFP 1490nm-TX/1310nm-RX 10km Transceiver
SKU00684G 1000BASE-BX SFP 1310nm-TX/1550nm-RX 10km Transceiver
SKU00685G 1000BASE-BX SFP 1550nm-TX/1310nm-RX 10km Transceiver
SKU10607Z 1000BASE-BX compact SFP 1490nm-TX/1310nm-RX 10km Transceiver

Related Article: A Brief Introduction of BiDi SFP Transceiver
Related Article: Can I Connect Optical Transceivers of Different Brand?

Can We Interconnect SFP, SFP+, XFP, X2 and XENPAK?


There are many kinds of 10G optical transceivers in the market such as SFP+, XFP, X2 and XENPAK. So when we use these modules, the most confusing problem is if we can interconnect SFP+, XFP, X2 and XENPAK. Besides this, some module users also want to know if they can connect SFP to SFP+ or if then can connect 10GBASE-SR modules to 10GBASE-LR modules. In this article, I will display some common questions often asked by module users and give the right answer mainly based on Cisco optical transceivers.

1. Can we interconnect SFP-10G-SR to XENPAK-10GB-SR or X2-10GB-SR?
The answer is yes. For this problem, you just need the correct optic on each side. If your optics are singlemode you need singlemode patch cord. If your optics are multi-mode then you need multi-mode patch cord. SFP-10G-SR, XENPAK-10GB-SR and X2-10GB-SR are all multi-mode optics, so a multi-mode fiber can solve this problem.

2. Can LC-SC patch cord connect X2-10GB-SR between SFP-10G-SR?
Yes, it’ll work fine as long as your fiber patch cord is multi-mode. Actually, the SFP+ requires LC connector but the X2 may require a SC connector. So when connect SFP-10G-SR to X2-10GB-SR, we must use a LC-SC patch cable (LC connector on one fiber end, SC connector on the other fiber end).


3. Is it possible to connect X2-10GB-LR to SFP-10G-SR?
The answer is not possible. The Cisco X2-10GB-LR module supports a link length of 10 kilometers on standard single-mode fiber (SMF, G.652). However, the Cisco SFP-10G-SR module supports a link length of 300m on OM3 multi-mode fiber (MMF,OM3) and 400m on OM4 multi-mode fiber (MMF,OM4). Actually, you need to use modules with the same wavelengths, i. e. SR to SR or LR to LR.

4. Can we connect SFP-10G-SR to GLC-SX-MM?
The SFP-10G-SR is 10 Gbps only. The GLC-SX-MM is 1 Gbps only. This question means can we force SFP-10G-SR to use 1Gbps speed?  This is a very common question and the response will always be the same. The answer is NO. Because the SFP-10G-SR is 10 Gbps only. It runs at 10 Gbps link rate and no other speed. GBIC, SFP, X2, QSFP, CFP modules will only negotiate to one speed and one speed only. You cannot interconnect them.


5. Can we connect GLC-SX-MM to GLC-LH-SM?
Some users wonder if they can use GLC-SX-MM together with GLC-LH-SM? In fact, the GLC-SX-MM is multi-mode LED-based. The GLC-LH-SM is singlemode laser-based. They may (sometimes) work with mode conditioning patch (MCP) cables but it’s not generally a good idea unless it’s completely unavoidable.

FS offers a variety of fiber optic transceivers (SFP+, XFP, X2 and XENPAK) at very economical prices which can satisfy your requirements from 1G to 100G Ethernet. In addition, all these optical transceivers are in stock and you can enjoy the same day shipping service. For more information, please contact us over

Related Article: Cisco SFP-10G-SR: All You Need to Know

Knowledge of SFP Auto-Negotiation


We usually see fiber optic transceiver with descriptions like “10/100/1000 copper SFP” shown in the picture below. Then what does “10/100/1000” mean? In fact, it refers to SFP modules that support 10/100/1000 auto-negotiation. With the function of auto-negotiation, SFP can operate on 10 Mbps, 100 Mbps, and 1000 Mbps. Some knowledge of SFP auto-negotiation will be given in this article.

Copper SFP Auto-Negotiation

What Is Auto-Negotiation?

Today a number of technologies, such as 10Base-T, 100Base-T, and 1000Base-T, use the same RJ-45 connector, creating the potential for connecting electrically incompatible components together and causing network disruption. To eliminate the possibility of dissimilar technologies interfering with each other, the Institute of Electrical and Electronics Engineers (IEEE) developed a protocol known as auto-negotiation. Auto-negotiation allows devices to perform automatic configuration to achieve the best possible mode of operation over a link. Devices with this feature will broadcast their speed (10 Mbps, 100 Mbps, and 1000 Mbps) and duplex (half/full) capabilities to other devices and negotiate the best between two devices.

Types of SFP Auto-Negotiation

There are two types of auto-negotiation that operate simultaneously within the SFP module. One is the 1000Base-T auto-negotiation, the other is 1000BASE-X auto-negotiation. The difference between them is that 1000BASE-T auto-negotiation is conducted over the Cat 5 cable between the two 1000BASE-T devices while 1000BASE-X auto-negotiation is typically conducted between two host systems over fiber. Usually, Gigabit SFP transceivers use auto-negotiation to advertise the following modes of operation: 1000Base-T in full or half duplex, 100Base-TX in full or half duplex, and 10Base-T in full or half duplex.

SFP Auto-Negotiation in Real Applications

A few cases of how SFP auto-negotiation operation works in an actual application are shown below:
Case1: A SFP is inserted into a switch with no copper cable.
Regardless of whether the MAC has 1000Base-X auto-negotiation turned on or off, 1000Base-X auto-negotiation will not complete. Because 1000Base-X auto-negotiation will never complete before 1000Base-T link is established.

Case2: After SFP is inserted into a switch w/ 1000Base-X auto-negotiation, copper cable is inserted.
SFP will store the 1000Base-X abilities advertisements from the MAC. 1000Base-T auto-negotiation will be restarted using abilities advertisements from the MAC. After 1000Base-T link is completed, SFP will send 1000Base-X abilities advertisements and acknowledgement codewords to the MAC. 1000Base-X link will then be established.

Case3: After SFP is inserted into a switch w/ no 1000Base-X auto-negotiation, copper cable is inserted.
SFP will detect that only idles are received from the MAC. 1000Base-T link will be established based on abilities set by hardware strap options on the PHY. After 1000Base-T link is established, the SFP will wait for 200 minutes and go into bypass mode. 1000Base-X link will then be established.

Case4: Both 1000Base-T and 1000Base-X link has been established. Copper cable is then unplugged.
When the copper cable is unplugged, 1000Base-T link will be broken. This will restart auto-negotiation both for 1000Base-X and 1000Base-T.

Case5: Copper cable is first plugged into the SFP, then SFP with cable is inserted into switch.
This case is the same case 2 and 3. If the SFP is powered up with copper cable already plugged in, it will go through the same auto-negotiation process.

After reading this article, you may know more about SFP auto-negotiation. Fiberstore have a lot of 10/100/1000BASE-T auto-negotiation 100m RJ45 copper SFP fiber optic transceivers in stock with high quality and low price. For more information, please visit

Related Article: Compatible SFPs for Ubiquiti EdgeSwitch and UniFi switch

Related Article: SFP Module: What’s It and How to Choose It?

GBIC vs SFP—When to Choose What?


GBIC and SFP are both a kind of hot-pluggable optical transceiver which is mainly used to convert between the optical signal and electrical signal. GBIC stands for Gigabit Interface Converter. SFP is short for Small Form-factor Pluggable. Usually, SFP is considered as an upgraded version of GBIC module. However, GBIC and SFP are equal in performance. The only major difference between them is their size. SFP module is much smaller than GBIC module. For this reason, the SFP is also called mini GBIC in most cases.

These years, due to the small size of SFP, GBIC module is being replaced by SFP. Why is this happening? In fact, the most common reason is that the big size of GBIC module was not feasible to provide more number of interfaces on a line card or a switch since it occupies more space. In order to resolve this issue people came up with SFPs which were smaller in size hence you can have more interfaces on the same line card or switch compared to GBICs. Let’s take an example, have you ever heard of a 48 port GBIC line card on 6500 switch. The answer is no, because it’s not feasible to have 48 big GBIC interfaces on the form factor of the line card. But a 48 port SFP line card exists.

gbic module

Knowing the differences between these two modules, then which one should you choose? In general, it actually depends on the line card or the switch you have. Usually, the line cards and switches comes with empty GBIC or SFP slots where you need to purchase the GBIC module or SFP modules respectively and insert in those empty slot. However, if you already have a switch or line card which has GBIC slots you have to use GBICs, simply because SFPs won’t fit in and vice versa.

Another case where you don’t have a switch or line card and want to make a decision whether to use a GBIC or SFP will actually depend on the number of interfaces required and availability of the switches and line cards specific model. For example, if you want two fiber interfaces on a line card on 6500 switch, you won’t go for a 48 port SFP line card, instead you’ll use a 2 port GBIC line card. If you need some 24 fiber interfaces you won’t use a 16 (or 18 not sure) port GBIC line card, you’ll use a 48 port SFP line card.

After reading this article, you may get a clear understanding of whether to use SFP module or GBIC module. Fiberstore provides all kinds of SFP modules, such as 1000BASE-T SFP, 1000BASE SX SFP, 1000BASE LX SFP etc. If you need to buy GBIC modules, I also recommend you to visit Fiberstore. All their GBIC modules come with a lifetime advance replacement warranty and are 100% functionally tested.

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