User guide

PTP 800 Series User Guide Planning 1+1 Hot Standby links
phn-2513_004v000 (Oct 2012)
2-35
Planning 1+1 Hot Standby links
When planning 1+1 Hot Standby links, follow the process described in this section.
Concept of a 1+1 Hot Standby link
A 1+1 Hot Standby link provides protection against single point equipment failure. This is
achieved by the deployment of extra equipment which automatically takes over the
operation of the link in case of failure.
The two main advantages of a 1+1 Hot Standby link are:
• Better availability. In the unlikely event of equipment failure, the 1+1 Hot Standby link
becomes operational again with a down time of less than 250 ms. This is compared to a
lengthy down time in the event of equipment failure in a 1+0 link. This may be
particularly important in remote locations or for safety critical applications.
• Maintenance operations can be carried out, such as installation of new software, with a
minimum of interruption to the service provided by the link.
Antenna, RFU and CMU configurations for 1+1
Do not install an ODU and an IRFU in the same link, as they cannot interwork.
Select one of the following 1+1 Hot Standby link end configurations: