When link distances are a few kilometers (nominal) one way transmit to receive, SISNet Repeaters can be connected with multimode fiber-optic cables to form the remote peer ring. When link distances exceed a few kilometers one way, SISNet Distance Extenders can be used to convert multimode fiber-optic signals to single mode fiber-optic signals to extend the remote peer ring.
The SISNet Repeaters connect transmit to receive, transmit to receive to form a fiber-optic ring. It is highly recommend that you connect SISNet Repeaters in a counter-rotation topology in which two signal paths, one in each direction, exist in the ring. This topology increases availability in the event of a failure in a single SISNet Repeater pair.
The following figure shows a multimode fiber-optic ring with a counter-rotation topology. The primary SISNet Repeaters are connected 1-2-3-1 and the secondary are connected 3-2-1-3. If any single pair in this ring fails, the remaining two pairs continue to communicate. No SISNet Distance Extenders are used in this remote peer ring.
