OTN is based on WDM technology, optical transport network layer in an organization's network, it is the next generation of backbone transmission network. OTN is the next generation through a series of ITU-T recommendation G.872, G.709, G.798, etc. norms "digital transmission system" and "optical transmission system" that will solve the traditional WDM networks without wavelength / sub-wavelength services poor scheduling, network capacity is weak, weak protection and other issues.

The rapid development of information technology, the popularity of network-based technology advances, prompting data center construction continues toward large-scale, high-density, high transfer rate, pluralism, virtualization, intelligent, green direction. At the same time, for faster data transfer rates, smaller footprint, lower energy consumption needs, making the data center physical infrastructure as an important part of the cabling system more and more people's attention. Fiber and copper cabling system in the data center are two basic transmission medium, compared with copper systems, fiber-optic network with greater bandwidth, faster transfer rates, longer distances, more slender volume, and stronger anti-interference ability and so on. Therefore, although limited by the high price factor optical fiber, optical fiber can be completely replaced by copper, but the data center construction "Light of Copper" trend is inevitable.

This article discusses the function of WDM technology OADM based systems, the node structure and its products and applications, and its drop multiplexing tributary signals in wavelengths, called optical channel. OADM node device is one of the key equipment of all-optical network.

In 1988, the United States launched the first of a digital transmission standard, the entire network clock synchronization levels are from a very precise master clock (using expensive cesium atomic clock, accuracy better than plus or minus 10 -11 th).

Many people do not know the difference between SFP and SFP+, so sometimes unnecessary trouble. 10G module has gone from 300Pin, XENPAK, X2, XFP development, and ultimately with the same size and SFP 10G transmission signal, which is the SFP+. SFP With its compact and low cost advantages to meet the equipment needs of high-density optical module, the standard introduced from 2002 to 2010 has replaced 10G XFP become the market mainstream.

Divided according to the rate of 155M / 622M / 1.25G / 2.125G / 4.25G / 8G / 10G, used more on the 155M and 1.25G market, 10G demand to increase positive attitude development.

SFP is SMALL FORM PLUGGABLE (Small Form Factor Pluggable) acronym, can be simply understood as an upgraded version of GBIC, SFP modules are small by half. But on the same panel configuration more than double the number of ports. Other features SFP and GBIC modules basically the same. Some switch vendors said the SFP module as small GBIC (MINI-GBIC).

FTTH (Fiber To The Home), the name suggests is an optical fiber directly to the home. Specifically, FTTH refers to the optical network unit (ONU) installed at the home user or business user, a series of optical access user of the optical access network application types except FTTD (fiber to the desk) the closest off. FTTH is a distinctive feature not only provides more bandwidth, but also enhances network data format, speed, wavelength and protocol transparency, relaxes the environmental conditions and power requirements, simplifying maintenance and installation.

APON the mid-1990s developed, and was able to develop a fiber-based standard include IP data, video and Ethernet services for business and residential users, logical ATM and PON were selected as the network protocol and network platform, because ATM is seen as the only able to provide various types of communication protocols, and is the most economical broadband PON fiber solution.

Optical connector, also known as fiber optic connector, commonly known as joint activities. It is used for the detachable (activity) connected between the optical fiber and optical fiber device. It is the two end precision optical docking, so that the light energy emitted optical output can maximize the receiving fiber coupled to go, and effects due to their involvement optical link and to minimize the impact on the system.