56
DECrepeater 90FS Installation and Configuration
Redundant Fiber-Optic Link Configuration (Cont.)
•
Redundant-Link Pair
The RLP is a pair of fiber-optic links that provides backup communication in the event
of transmitter, receiver, or cable failures.
•
Master
The master is the DECrepeater that contains the master control algorithm (MCA) for
the ports in the RLP. This algorithm controls the Link Enable signal that goes to each
of two ports in the RLP. The master uses this signal to enable the primary port until a
failure is detected through the Link Status signal. When a failure is detected, the
MCA disables the primary port and enables the secondary port.
•
Responder Port
The RLP can contain two responder ports (referred to as responders) on the remote
end of the links from the master ports. The responders are independent of each
other, but reside on the same LAN (or extended LAN) as the master. A responder can
signal the master when it detects a failure on its receive portion of the link. The
responder does this by disabling the Link Idle signal on its transmit port until the
receive portion of the link is operational again.
•
Non-Responder Port
Any standard 10BaseFL device ports can be non-responder ports (referred to as
non-responders). Unlike a responder, a non-responder cannot signal the master
when there are receive link failures on its end of the link. If you define an RLP with
non-responders, only partial fault detection is provided on the RLP.
•
Primary Link
Defined at initialization time by the MCA, the primary link is initially the active link
providing Ethernet communications. Activity defaults to the primary link after a reset
condition.
•
Secondary Link
The secondary link is the other link of the RLP to which the master fails over if there is
a failure in the primary link.
Содержание DECrepeater 90FS
Страница 78: ......
