Hardware manual

80-001113 SysLINK Administrator’s Guide Page 52
Lightweight Heartbeat Settings
The Lightweight Heartbeat (LWHB) feature is designed to provide a low overhead method
for units to check in more frequently than existing SOUP methods. This is particularly useful
when used with cellular data plans that provide only a few MB of data per month. Full
SOUP updates can be scheduled at most every day and have relatively high overhead (20-
30Kbytes per update). SOUP heartbeats can be scheduled more often but still relatively high
overhead (5-6K per heartbeat). The LWHB allows units to:
 Check in frequently - providing an "I'm up" indicator
 Check to see if there are further actions that should take place - like a full SOUP
update
The LWHB server can record the source IP address which, in the cellular world can change
multiple times a day
LWHB does not use SSL. It connects to a server using either UDP or TCP (configurable) on a
configurable port number. The local IP port can also be configured if necessary to receive
replies from the server through a firewall.
Using UDB, each LWHB takes about 60 bytes. Using TCP, each LWHB takes about 650 bytes.
You must also take into account periodic DNS lookups for the hostname.