When It's Best to Use GBIC and When to Use SFP?

Recently many users ask when they choosing a card for their switch/router, they should choose either cards that take SFP or cards that take GBIC. It seems to be a headache for them because they are not clearly know the differences of them. Thus, today, we are mainly going to discuss that when it's best to use GBIC and when to use SFP.

GBIC (gigabit interface converter)

GBIC is a hot-swappable input/output device that plugs into a Gigabit Ethernet port or slot, linking the port with the network. GBIC is a standard for transceivers, commonly used with Gigabit Ethernet and fiber channel. GBIC module is hot pluggable, this feature allows a suitably designed enclosure to be changed from one type of external interface to another simply by plugging in a GBIC having the alternative external interface. Generally, GBIC is with the SC connector. The GBIC standard is non-proprietary and is defined by the Small Form Factor committee in document number 8053i. The first publication of the proposal was in November 1995. A few corrections and additions were made through September 2000.

SFP (small form-factor pluggable)

SFP is a specification for a new generation of optical modular transceivers. The form factor and electrical interface are specified by a multi-source agreement (MSA). SFP is also known as a Mini GBIC as its function is somewhat similar to the GBIC transceiver while SFP is smaller than it. SFP transceivers are designed to support SONET, gigabit Ethernet, Fibre Channel, and other communications standards. Due to its smaller size, SFP is now more and more widely used for both telecommunication and data communications applications.

GBIC & SFP Interface Types

For every type of GBIC and SFP transceivers, it works with different wavelengths at a designated location or distance. For examples, SX SFP uses 850nm for a maximum of 550 meters, LX SFP uses 1310nm for a maximum 10km, ZX SFP could reach 80km or copper SFP RJ45 interface. We can easily distinguish via the information in their names or models, ie. 1000BASE-T SFP, 1000BASE-SX SFP, 1000BASE-LX/LH SFP, 1000BASE-ZX SFP, 1000BASE-CWDM SFP, or 1000BASE-DWDM SFP. In addition, the DOM function for an SFP is discretionary. It supports the users to locate the real-time working status of SFP. The famous brand of GBICs or SFPs are Cisco, Finisar, HP, Juniper, Extreme Network and so on. There is a little difference in the features of each brand's GBICs and SFPs and they support their corresponding brand's switches/routers.

When it's best to use GBIC and When to use SFP?

According to the above definitions of GBIC and SFP, you may have a further understanding on both of them. There is only one difference of them. SFP is smaller than GBIC. Because the smaller size of SFP (almost half the volume of GBIC), we can configure double number of ports on the same panel which increases the utilization rates of switches/routers. Other basic functions of SFP is almost the same with the GBIC and they are equal in performance. Though there are some users still using the GBIC as their old divice which can not be updated to support SFP, GBIC will gradually be obsoleted and replaced by SFP. So the answer to the question "When it's best to use GBIC and When to use SFP?" is obvious. SFP is your choice. Of course, except GBIC and SFP, there are SFP+, XFP, QSFP/QSFP+ etc. new generation of transceivers which can meet all kinds of your requirements. These new types of transceivers will be discussed in other aticle and not state here one by one. If you are interested in them, please focus continuously on my blog. Or if you need these products, Fiberstore will be a good place for you.

Recommendation of The Best-selling Brand Compatible Transceivers

• Cisco: GLC-SX-MM, GLC-SX-MMD, GLC-LH-SMD, GLC-T, SFP-GE-T
• Finisar: FCLF-8521-3, FTRJ8519P1BNL, FTLX8571D3BCV
• Netgear: AFM735, AGM734, AGM731F
• HP: J4858C, 455883-B21, J9143B, JD089B
• D-Link: DEM-310GT, DEM-311GT

Article Source: GBIC or SFP transceiver