Possible causes include:
1. The optical module or board was faulty.
2. Interconnection optical fibers and corridor fibers were faulty.
3. The distance between the NE40E and the interconnected device was greater than that the optical module supported.
4. An improper type of optical fibers were used.
Huawei performed the following operations to address the problem:
1. Switched the faulty interface and an up interface on the NE40E. The faulty interface became up and the originally up interface became down. Therefore, the problem was not caused by a fault on the optical module or board.
2. Tested the transmit and receive power on the interconnected interfaces. The power was normal. Therefore, the problem was not caused by a fault on the interconnection or corridor optical fibers.
3. Found the distance between the interconnected devices was about 180 m, within 300 m that the optical module supported.4. Checked the optical fibers and found that the device used 50 um diameter jumpers (OM3) and the corridor optical fibers used 62.5 um diameter jumpers (OM1). The 10GE optical module required a dispersion tolerance of 400ps/nm to 800ps/nm and therefore OM3 multi-mode optical fibers must be used.