光模块常用知识（Knowledge of light module is common）

光模块常用知识（Knowledge of light module is common） 光模块常用知识(Knowledge of light module is common) Common knowledge of optical modules The commonly used optical modules of Ethernet switches are SFP, GBIC, XFP, XENPAK. Chinese names are not commonly used and can be easily understood: SFP: Small Form - factor Pluggable transceiver, Small encapsulated Pluggable transceiver GBIC: GigaBit Interface Converter, GigaBit Ethernet Interface Converter XFP: 10 - Gigabit small Form - factor Pluggable transceiver multimegabyte Ethernet interface small encapsulated Pluggable transceiver XENPAK: 10 Gigabit EtherNet Transceiver PAcKage multimegabyte EtherNet interface Transceiver assembly encapsulation Fiber-optic gigabit Ethernet includes 4 standards including 1000base-sx, 1000base-lx, 1000base-lh and 1000base-zx. Among them, SX (Short wave) is Short wave, LX (longwave) is long wave, LH (long - haul) and ZX (extended range) are ultra long wave, 1000base-sx and 1000base-lx can both use single-mode fiber and multimode fiber. And 1000base-lh and 1000base-zx can only use single-mode fiber. Through the diplay interface command, the port type information of the light module can be displayed in the software. The display format is: The meaning of each field is shown in the table below The value of the field name implies The maximum speed 10G 10G 10G Ethernet supported by XXXX optical module 1000 1000M Ethernet 100 100M Ethernet 155 m SDH 622 m SDH 2.5 G SDH 10 g SDH YY transmission distance SX LX in the distance LH + long distance T the interfaces ZZZ connector type SFP SFP interface GBIC GBIC interface XENPAK XENPAK interface XFP XFP interface AAAA interface optical fiber type MM + center wavelength multimode fiber SM + center wavelength single mode fiber BBBB additional features (optional) BIDI single - fiber bidirectional module CWDM CWDM module STACK STACK module For an interface that does not insert a light module, it is shown as ZZZ_NO_CONNECTOR, where ZZZ is consistent with the above connector type. For the unrecognized light module, the display is ZZZ_UNKNOWN_CONNECTOR, where the ZZZ is consistent with the above connector type. For modules with no additional features, no additional feature items are shown For example, the port information shown on Ethernet port gigabitethernet2/1/1 is shown below [fabric - 56] display intterface g2/1/1 Gigabitethernet2/1/1 current state: UP IP address Frames' Format is PKTFMT_ETHNT_2, Hardware address is 00e0 - fc10-4378 Media type is optical fiber, loopback not set Port hardware type is 1000_BASE_SX_SFP The sx indicates that the port is a short distance 1000M SFP module Parameter meaning 850nm 1310nm 1550nm wave wavelength 100Mbps 1000Mbps transmission rate 10km 70km link length Type of SX LX laser (short-wave long wave) Work mode of SM MM (single mode multimode) Optical fiber connector The fiber-optic connector consists of plugs of fiber and fiber, and the plug is made up of pins and peripheral locking structures. According to different locking mechanism, fiber connector can be divided into FC type, SC type, LC type, ST type and MTRJ type. The FC connector adopts thread locking mechanism, which is the most used optical fiber activity connector. SC is a rectangular joint, developed by NTT, without thread connection, and can be inserted directly. Compared with FC connector, it has small operation space and easy to use. Low-end Ethernet products are very common. LC is a Mini - type SC connector developed by LUCENT, which has a smaller volume and has been widely used in the system. It is a direction for the development of fiber optic activity connector in the future. Low-end Ethernet products are very common. ST connector is developed by AT&T, with a bayonet type locking mechanism, the main parameter index and FC and SC connectors, but is not widely used in the company, usually used in multimode device connection, use more when docking with the other factory equipment. The pins of MTRJ are plastic, which are positioned through the steel needle. As the number of inserts increases, the mating surfaces will wear out and the long-term stability is not as good as the ceramic insert connector. Knowledge of optical fiber A fiber optic is a conductor that transmits light waves. Optical fiber can be divided into single mode fiber and multimode fiber from the mode of optical transmission. Optical transmission in single mode fiber has only one basic mode, which means that the light travels only through the inner core of the fiber. The transmission band of single-mode fiber is widely used in this paper because it completely avoids the mode scattering. Optical transmission in multimode optical fiber has several modes, because of dispersion or aberration, the transmission performance of this fiber is poor, the frequency band is narrow, the transmission speed is small, and the distance is short. Characteristic parameters of optical fiber The structure of the optical fiber prefabricated silica fiber rod is made, the outer diameter of the multi-mode fiber and single-mode fiber is 125 mu m. The body is divided into two regions: Core and Cladding layer. The diameter of single mode light fiber core is 8 ~ 10 mu m, and there are two standard specifications for multi-mode fiber core diameter, which are 62.5 mu m (American standard) and 50 mu m (European standard). We often see the description of the optical fiber specification in the installation manual > : 62.5 mu m / 125 mu m multimode fiber, of which 62.5 mu m is the core diameter of the optical fiber, and 125 mu m is the outer diameter of the optical fiber. The wavelength of light used for single-mode fiber is 1310nm or 1550nm. Multimode optical fiber USES an optical wavelength of more than 850 nm. Single mode fiber and multimode fiber can be distinguished from color. Single mode fiber external body is yellow, multi-mode fiber outer body is orange red. Single mode fiber and multimode fiber can be distinguished from color. Single mode fiber external body is yellow, multi-mode fiber outer body is orange red. Gigabit's self-negotiation Gigabit can work in both mandatory and self-negotiation modes. In the specification, the gigabit port only supports 1000M rate and supports Full duplex and Half duplex mode. Since the negotiation and enforcement is the fundamental difference between both to build physical link when sending code flow is different, the negotiation model is sent/C/code, namely Configuration (Configuration) stream, and force mode to send/I/code, namely idle stream. Gigabit self-negotiation process Both sides are set to self-negotiation mode Send each other a/C/stream, if received three consecutive identical/code/C and to receive the code flow and work style to match this end, it returns to the other side with an Ack response/C code, the client receives the Ack information, that can be Shared, both set port for the UP state 2. One end is set to self-consultation and one end is mandatory From the negotiation side send/C/yard stream, the mandatory terminal send/I/yard stream, the mandatory end can't provide the negotiation information to the end, nor can you return an Ack reply to the end, so the negotiation side DOWN. But the force side itself can identify/C/code, and think that the right end is the port that matches itself, so directly set this end port to be UP state Both ends are set to mandatory mode The two parties send/I/yard stream, and when one end receives/I/yard stream, it is considered that the opposite end is the port that matches itself, directly setting this end port as UP state For commonly used 12 kinds of light module on the market (type of specific see attachment), the equipment on March 31, 2008, the factory will gradually increase the amount of judgment on these light module manufacturers, for the light of the original certification of module, will take the initiative to send alarm information to the log host and network management software, users can also through the Display transceiver interface command to view the light module manufacturer information. Example: The < H3C > display transceiver interface GigabitEthernet1/1 transceiver information: Base_lx_sfp Transceiver Type: 1000 The Connector Type: LC Where (nm) : 1310 Transfer short (km) : 10 (9 um) Digital Diagnostic Monitoring: YES Vendor Name: H3C Ordering Name: SFP - GE - LX10 - SM1310 3. For the above 12 light modules, if the production date is on March 31, 2008, the equipment may have false alarm information. If you have any question in your use, please contact China 3800 for confirmation. 12 light module Numbers used for encryption after 31 March 2008: Number product description product model 1 light module - SFP 100M / 155M - multimode module - (1310nm, 2km, LC) sfp-fe-sfs-mm1310-a 2. Light module - SFP 100M / 155M - single mode module - (1310nm, 15km, LC) SFP - fe-lx-sm1310-a 3. Light module - SFP 100M / 155M - single mode module - (1310nm, 40km, LC) SFP - fe-lh40-sm1310 4. Light module - SFP 100M / 155M single-module long distance module - (1550nm, 80km, LC) sfp-fe-lh80-sm1550 5 light module - SFP - GE - multimode module - (850nm, 0.55km, LC) SFP - GE - SX - MM850 - A 6 light modulation-sfp - GE - single mode module - (1310nm, 10km, LC) sfp-ge-lx-sm1310-a 7 light module - SFP - GE - single mode module - (1310nm, 40km, LC) SFP - GE - lh40-sm1310 8 light modulation-sfp-ge - single mode module - (1550nm, 40km, LC) sfp-ge-lh40-sm1550 9 light module - SFP gigabit BIDI light module - TX1310 / RX1490, 10km, LC sfp-ge-lx-sm1310-bidi 10 light module - SFP gigabit BIDI light module - TX1490 / RX1310, 10km, LC sfp-ge-lx-sm1490-bidi 11 light module - SFP 100mb BIDI light module - TX1310 / RX1550, 15km, LC SFP - fe-lx-sm1310-bidi 12 light module - SFP 100mb BIDI optical module - TX1550 / RX1310, 15km, LC sfp-fe-lx-sm1550-bidi