The 100G link between buildings is fast to lay out cables, but easy to overturn when it is opened: in projects where the link can be on but there are constant bit errors, flashes, and low-light alarms, the cost of troubleshooting often exceeds the construction itself. The correct startup sequence is three steps: first make an attenuation budget, then test the channel and termination, and finally bake the machine for long-term error errors and file them.

Step 1: Use measured channel data to make a budget

First, use an OTDR to measure the optical fiber between buildings and record the length, total attenuation and loss of each connector. The attenuation of G.652 single-mode in the 1310nm window is generally estimated at about 0.35dB per kilometer. Each movable connector is calculated as 0.5dB and the splice point is calculated as 0.1dB. Then use the module transceiver power range to deduct it. It is recommended to leave a margin of more than 3dB in engineering. The scenarios between buildings ranging from 100 meters to kilometers are mostly LR4 scenarios. For longer distances, choose ER4. When short links are directly connected to ER4, an optical attenuator must be added to prevent light receiving overload.

Step Two: Termination and Cleaning Check Again

  • Unify the LC/UPC on the distribution frame and jumpers and check the polarity, refer toLC-LC single mode dual core jumperSuch standard parts;
  • Align the MPO pins according to the card position direction, and do not insert the wrong fiber sequence for LR4 two-core single-mode;
  • The end face of the connector should be inspected and cleaned before insertion. Most low-light faults are caused by end face contamination;
  • The jumpers should avoid sharp edges of the cabinet, and the bending radius is usually not less than 30mm.

Step 3: 24-hour error roasting machine and recording

After the link goes online, run the link at full load for 24 hours. Observe the port CRC, packet loss, optical power and temperature trends reported by DDM, and compare it with the factory test records. EB-LINK high-speed modules are tested one by one before shipment. The test records can be traced according to the serial number. If the deviation exceeds the normal range, it can be judged whether to replace the module or repair the optical fiber. Archive the OTDR curve and error log before acceptance. Operation, maintenance and subsequent expansion are well documented. The actual practice can be referred to.100G optical fiber interconnection upgrade between buildings in a large data center in East China.

The attenuation budget comes first, the terminal cleaning comes second, and the error-freeing machine ends. Following these three steps for an inter-building 100G project, the one-time lighting rate will be much higher, and the complete scene design can be seenData center high-speed interconnection solution.