Important! Metropolis
®
DMXplore selects the path-level signal
with the best quality.
Unidirectional switching
Unidirectional switching refers to protection switching that is
performed in the receive direction only. The transmitting terminal
transmits the same path-level signal on two paths. The receiving
terminal monitors the two path-level signals independently and
chooses one path-level signal as the active path and the other
path-level signal as the standby path. Metropolis
®
DMXplore selects
the incoming path-level signal with the best quality (based on the
automatic path selector criteria).
Nonrevertive switching
UPSR switching is nonrevertive. When a protection switch occurs, the
receiving terminal selects the signal from the standby path. In
nonrevertive switching, when the fault clears the receiving terminal
does not switch back to the original path.
UPSR architecture
Figure 4-1, “UPSR switching example” (4-15)
illustrates an example
of UPSR protection switching. The UPSR switching is performed in
the receive direction. If the active incoming path-level signal fails, the
circuit pack chooses the stand-by path-level signal. In the transmit
Unidirectional path-switched ring switching
Maintenance overview
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4 - 1 4
Lucent Technologies
365-372-333 R2.1
Issue 4, June 2005
