Net Optics Optical Bypass Switch w_Heartbeat - Manual (Page 9)

5
Optical Bypass Switch with Heartbeat
Power Loss Bypass
The Optical Bypass Switch protects link integrity when the attached in-line
device loses power. To install the Optical Bypass Switch for this type of
protection, the switch should share the same power source as the in-line
appliance. If you are using redundant power supplies for the switch, make
sure that both are connected to the same power source as the in-line device .
Heartbeat Bypass
The Optical Bypass Switch with Heartbeat protects against both physical link
failure and application failure on the in-line appliance. The switch checks
the path through the in-line appliance by sending a packet every second from
Monitor Port C . The switch validates the path when it receives the packet
on the Monitor Port D. If the switch does not receive the packet as expected
three times in a row, the switch automatically enters Bypass Enabled (ON)
mode .You can change the number of the heartbeat packets required before the
bypass switch enters Bypass Enabled mode from the bypass switch CLI (see
Configuring the Bypass Switch on page 6).
Below is the default IPX heartbeat packet sent once every second from the
Monitor Port C. You can change the default timing of the heartbeat packet
and the heartbeat packet from the bypass switch CLI (see Configuring the
Bypass Switch on page 6).
The switch continues to send the bypass packet and will return to Bypass
Disabled mode when it receives three consecutive packets on Monitor Port D .
The default IPX and IP packets are shown on the following page. Units are
shipped from the factory with the IPX packet. When the factory defaults are
restored using the "z" CLI command (see "To restore the bypass switch to
factory defaults" on page 11), you will be able to select either the IPX or IP
packet .