GB optical GBIC and SFP interface specifications

1. What is GBIC??

GBIC is short for Giga bitrate interface converter. It is an interface device that converts Gigabit electrical signals into optical signals. GBIC is designed for hot swapping. GBIC is an Interchangeable product that complies with international standards. The gigabit switches designed with GBIC interfaces share a large market share due to flexible exchange.

2. What is SFP??

SFP is short for small form pluggable. It can be understood as an upgraded version of GBIC. The size of the SFP module is half that of the GBIC module. You can configure more than twice the number of ports on the same panel. Other functions of the SFP module are basically the same as those of GBIC. Some switch manufacturers call the SFP module A miniaturized GBIC (MINI-GBIC ).

3. What types of optical fibers are available??

Multimode Optical Fiber is divided into two types: Multimode Optical Fiber and Single-Mode Optical Fiber. multimode optical fiber is widely used for short-distance communication because of its low cost and simple construction, multimode Optical Fiber is divided into two types: 50um core diameter and 62.5um core diameter. Among them, 62.5um is common, but its performance is not as good as 50um. Our GBIC-SX multimode products are suitable for these two multimode optical fiber, the transmission distance is 550 (on 50um optical fiber) and 330 (on 62.5um optical fiber ).

Single-Mode Optical Fiber is generally used for long-distance communication. The core diameter is 9um. Our single-mode GBIC products have a transmission distance of 10 km, 20 km, 70 km, and 120 km respectively on single-mode optical fiber. Generally, switch manufacturers only provide 10 km and 70 km models in a single mode. The 20 km product can effectively save the overall cost of the system integrator's specific network solution. The 120 km product is used in special ultra-long running environments.
Introduction to GBIC

GBIC is a hot-swappable input/output device that is inserted into a Gigabit Ethernet port/slot to connect the port with the fiber optic network. GBIC can be used and exchanged on a variety of Cisco products (see table 2), and can be mixed with 1000 basesx, 1000 baselx/LH, or 1000basezx interfaces that follow IEEE 802.3z one by one. Furthermore, Cisco is providing a 1000 baselx/LH interface that fully complies with the IEEE 802.3z 1000baselx standard, but its transmission distance on a single-mode optical fiber is as high as 10 kilometers, it is 5 kilometers farther than the ordinary 1000baselx interface. In short, with the continuous development of new functions, it is easier to upgrade these modules to the latest interface technology, so that the customer's investment can maximize the benefits. Figure 1 shows a GBIC.

Figure 1 Gigabit Interface Converter

Specification

The technical specifications of GBIC are shown in the table.

GBIC specifications
Specification	Description
Size (high 'Kuan' length)	0.39 '1.18' 2.56 inch (1' 3' 6.5 cm)
Connector	Multimode Optical Fiber: SC Single-Mode Optical Fiber: SC
Wavelength	SX: 850nm Lx/LH: 1300nm ZX: 1550nm
Wiring distance (max)	SX: 1804 feet (550 meters) Lx/LH: 32810 feet (10 km) ZX: 70 to 100 km

Port Wiring Specification

Generally, the GBIC module ports of different products have different requirements on the wiring specifications. Whether it is the wiring type or the wiring distance, the following analysis uses Cisco products as an example:

Cisco GBIC port Wiring Specification
GBIC	Wavelength (Nm)	Optical Fiber Type	Internal core specifications (micron)	Modal bandwidth (MHz/km)	Wiring distance
WS-G5484 SX1	850	Multimode Optical Fiber	62.5 62.5 50.0 50.0	160 200 400 500	722 feet (220 meters) 902 feet (275 meters) 1640 feet (500 meters) 1804 feet (550 meters)
WS-G5486 LX/LH.	1300	Multimode Optical Fiber 2 single-mode optical fiber (LX/LH)	62.5 50.0 50.0 9/10	500 400 500 -	1804 feet (550 meters) 1804 feet (550 meters) 1804 feet (550 meters) 32810 feet (10 km)
WS-G5487 ZX	1550	Single-Mode Optical Fiber	None	N/	70 to 100 kilometers

The following table lists the GBIC cabling specifications installed on the Gigabit Ethernet port. Note that all GBIC ports use SC connector, and the minimum cabling distance of all listed GBIC (multimode and Single-Mode Optical Fiber) is 6.5 feet (2 meters ).

1: Only multimode optical fiber is used.

2: requires pattern adjustment of the patch line (CAB-GELX-625 or equivalent product ). If the Multimode Optical Fiber uses a common patch line, the distance between 1000 baselx/lh gbic and the short link (several dozen meters) will lead to saturation at the receiving end, resulting in an increase in the bit error rate (BER. In addition, if the LX/lh gbic is used with a 62.5 micron multimode optical fiber, you must install a pattern adjustment patch line between the GBIC at both ends of the link and the multimode optical fiber. If the link distance exceeds 984 feet (300 meters), you also need to adjust the patch line in mode.

Note: To comply with IEEE Standards, the pattern adjustment patch line (CAB-GELX-625 or equivalent product) must be used ). IEEE found that when some types of optical fiber inner cores are used, the link distance cannot meet the requirements. The solution is to use the mode call.