System information

FCD 901 48
Issue R2A, 07.2009
XMP1 Release 5.5 System Description
Protection Switching Configurations
Page 2-76 Proprietary Information Aastra
2.7 Protection Switching Configurations
In order to ensure optimum reliability and availability of XMP1 even in case
of faults occurring in the network, the system offers the possibility of defining
protection switching configurations. The following protection switching
configurations are possible:
• Line protection switching
• Card protection switching
2.7.1 2 Mbit/s line protection switching
In line protection switching configurations, 2 Mbit/s data transmission
between two nodes is doubled by a second line. In this case, two port LEs
are operated in parallel in each node in the Tx direction. The Tx signal is
transmitted parallelly over both transmission paths.
Criteria for switchover to the protection path are
•AIS
•LOS
•LOF
• BER
-3
.
On detection of one of the above conditions in the operating path, the
control computer switches over to the protection path. A network
management system is not required for switchover.
Note: The protection path must not be occupied by 64 kbit/s
channels.
The automatic switchback function from the protection path to the operating
path (preferred path) if the switchover condition is no longer available can
be configured. When entering the routing data, please ensure that time slot
0 of the 2 Mbit/s signal is transmitted transparently between the terminal
stations.
Figure 2.33: Line protection switching
XMP1
1
2
2
1
Port
2 Mbit/s
el.
Port
2 Mbit/s
opt.
Code-transparent
transmission
Code-transparent
transmission
Port
2 Mbit/s
el.
Port
2 Mbit/s
opt.
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XMP1
1
2
3
4
1
2