Q: How to connect the optical fibers of NE80/40 to form RPR ring?
A: Correct connection of optical fibers of NE80/40 RPR is very important, and they must form a ring for normal working; otherwise, if the fibers are connected falsely, the ring will not be available even though the configure of LPU is correct.
For one RPR ring with n nodes (n>=2) as N1, N2,..., Nn, their direct optical fibers are connected as follows:
1. Make the A side of node N1 idle.
2. Connect the transmitting/receiving port of B side of node N1 to that at the A side of node N2.
3. Connect the transmitting/receiving port of B side of node N2 to that at the A side of node N3.
n. Connect the transmitting/receiving port of Bside of node N(n-1) to that at the A side of node Nn.
n+1. Connect the transmitting/receiving port of Bside of node Nn to that at the A side of node N1.
Note: Both A and B sides of RPR LPU with double subcard must be in the two continuous slots, and the one in odd slot must be at first. For example, slot 1 and slot 2, slot 3 and slot 4, etc. , of which the one in odd slot is A side, and the one in even slot is the B side. Pay attention to the numbering order of slots of NE80/NE40 series routers, particularly NE40-4 and NE40-2, of which the slots are numbered from the bottom to top, so the LPU at down side is the A side, and that above is B side.