Description of the problem

During normal operation of a PTN3900 at a company site, several 81EX2 boards frequently flash ETH_LINK_DOWN and REMOTE_FAULT alarms.

Processing

1. Query the local equipment for ETH_LINK_DOWN and REMOTE_FAULT alarms.

2, single board logs, found that the port has repeated up, down

3、Query the opposite port RMON performance statistics, found that there are FCS error packets

4. After modifying the port mode on the current network (changed from LAN mode to WAN mode), the fault disappeared.

Combined with the existing experience, it is suspected that there is radiation around the interference with the operating clock frequency of the LAN mode, resulting in port instability. Handheld spectrum tester to measure the site radiation exceeds the standard.

Root cause

A high-power radiation source antenna is installed and turned on indoors in the customer's server room, causing the amount of electromagnetic radiation near the PTN3900 equipment to seriously exceed the standard, thus affecting the normal operation of the veneer.

Solution

1. It is recommended that the customer adjusts the indoor layout of the site, removes the high-power radiation source, and makes the indoor electromagnetic radiation index within the norms (3V/m);

2、PTN3900 equipment needs to be grounded to ensure that PTN3900 equipment works normally and reliably.

PTN3900 equipment for equipment installation environment grounding requirements

PTN3900 equipment for the environment of electromagnetic radiation requirements

Recommendations and Summary

In the daily PTN machine room, it is recommended that customers do not place instruments and equipment related to high-power radiation sources to provide a good environment for the normal operation of the equipment, and strictly implement grounding measures to ensure the high reliability of the equipment.

The technical information related to this chapter and the SDH equipment troubleshooting process is provided by Shenzhen Optical Transmission Network Technology Co., Ltd (www.opticaltrans.com), reproduced and retained! Huawei SDH Optical Transmission Equipment,SDH Transmission Equipment Sales