There is only one long-distance module left in the warehouse and the link is only a few kilometers, or conversely, using a 10-kilometer gear to cover a link close to 40 kilometers, the two boundaries are different. EB-LINK splits them into several conclusions that can be determined according to the distance within the station.
Low distance range cannot withstand high loss links
The essence of the distance range is the combination of transmit power and reception sensitivity. The 10-kilometer range module is generally designed with a link budget of 10 to 13 dB. If the actual measured loss exceeds this number, the optical power at the receiving end will drop below the sensitivity, and the performance is often that the link can be established but packets are lost randomly. This situation can only be replaced bySFP+ 10G single-mode dual-fiber 40km optical moduleThis type of higher grade will not improve after repeated plugging and unplugging.
Determination of five alternative combinations
| alternative combinations | Conclusion | what to do |
|---|---|---|
| The 40km range is used for links of several kilometers | Available but needs to be protected against overload | Pressure the light collection back between the sensitivity and overload point |
| The 10km range is used on 40km links | Not available | Shift distance gear or shorten route |
| Multi-mode module uses single-mode fiber | Not available | Replace single-mode module and install single-mode jumper |
| Single-mode module uses multi-mode jumpers | It may be bright at short range but unstable | Change the jumpers together to the corresponding type |
| Single fiber end A is used as end B. | Doesn't make sense | Take materials in pairs according to wavelength |
There is no room for compromise between single-mode and multi-mode
The 850 nm multi-mode module with OM3 jumpers can run for tens of meters without any problem. If it is replaced with single-mode optical fiber, the mode field diameter will not match, and the loss will be too large to allow normal communication. On the contrary, the single-mode module with multi-mode optical fiber can only light up within a short distance and cannot support long links. The warehouse recommendsSFP Gigabit Multimode Dual Fiber Optical ModuleIt is packaged and labeled with the single-mode series. When picking up materials, you can take a look at the wavelength and fiber type labels to avoid mismatching.
There are three fixed judgment orders: first calculate which distance range the link loss falls in, then check whether the fiber type matches, and finally check whether the received light needs to be compressed a little. According to this sequence, most of the makeshift solutions on site can be turned off before power is turned on, saving a night resumption of work.