Radwin WinLink 1000 User Manual page 209

RADWIN Ethernet Ring
The steps below follow the numbering in
1. Normal operation
Ethernet traffic runs in the ring, but does not pass through the RPL, which is blocked. The
RPL does however, broadcast RPM packets through the ring.
2. Ring Link down, RPL notified
The RPL detects a link-down condition by the non-arrival of an RPM packet. It remains
blocked for the Minimum time for failure detection which is configurable using the
RADWIN Manager (see page 13-9).
3. Ring Link down, RPL unblocked for traffic
The RPL unblocks for Ethernet traffic after the Minimum time for failure detection
expires and no RPM message has been received.
4. Ring Link restored but still blocked for traffic
The Ring Link is restored, but remains blocked for the Minimum time for recovery, set
using the RADWIN Manager, to avoid rapid fluctuations leading to potential short term
loops (see page 13-9).
5. Ring Link restored, RPL blocked for traffic
The RPL blocks to Ethernet traffic after the Minimum time for recovery expires and
restores Ethernet traffic to the Ring Link (with a special RPM packet).
Return to 1.) Ring Link restored, RPL blocked for traffic
The ring is back to normal operation.
With RADWIN links, RADWIN's Ring Protection solution prevents Ethernet loops in the ring at
all times. The ring is always broken somewhere.
• Under a ring configuration a RADWIN Ring Link that was down and commences recov-
ery, keeps blocking Ethernet traffic. The RPL identifies this situation, blocks itself and
then unblocks the other Ring Link. This is the transition from step 4 to 5 in
Figure 13-1.
• If the failed hop is not a RADWIN link then there are two possibilities:
• If the hop Ring Link can signal that it is down by issuing a Loss of Signal (LOS) at
the Ethernet port, then the RPL will control the RADWIN link connected to that
port in the same manner as described above, to prevent an Ethernet loop.
• Otherwise, there may be a short loop period when the RPL is still open for traffic
and the Ring Link is also unblocked during the Minimum time for recovery.
WinLink 1000 User Manual
Figure 13-1:
Release 1.9.40
Chapter 13
13-3