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.
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.