DECrepeater 90FS Installation and Configuration
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Redundant Fiber-Optic Link Configuration (Cont.)
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Active Link
The active link is the link that is currently enabled by the master to carry Ethernet
traffic.
•
Standby Link
The standby link is the link that is currently disabled by the master and does not carry
Ethernet traffic. This port is held in readiness as a backup link in case the active link
fails. On a functional link, the responder can still place traffic on the link, but there is
no traffic from the master on that link.
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Master Control Algorithm
The Master Control Algorithm (MCA) enables only one link of the RLP at any time
and controls the RLP as follows:
1. The MCA enables the primary link at initialization time (assuming that there
are no failures on that link). This causes the primary link to become active.
2. The MCA monitors the primary link status for failures.
3. When the MCA detects a failure of the active link, the MCA:
a. Disables the active link.
b. Enables the standby link.
The active link always remains enabled (active) until a failure is detected on that link.
Redundant Fiber-Optic Link Operation
When you initially configure the DECrepeater 90FS for redundant operation, the
primary port is the active port and the secondary port is the standby port. In
operation, the active port communicates with its remote responder port until the
master detects a link failure or until the port is internally partitioned. If the standby
port is operational, the primary port is disabled, and the secondary port is enabled as
the active port. The failover typically occurs within 4 to 8 ms (15 ms worst case).
Once the primary link is repaired, it becomes the standby link. If the repeater detects
a failure in the (now active) secondary link, or if the port is internally partitioned,
failover occurs back to the primary port.
Содержание DECrepeater 90FS
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