I have been using JmDNSfor a while now, I could exploit it for the purposes of my application..every thing works fine for me (I have "announcer" machines and a "listening" one, and this latter machine can see the other devices and discover their information) It is true that I've managed to work with the JmDNS jar file, but I did it without totallyunderstanding what is going on in this file. Now I want to know about the effect of using JmDNS on the network load. I have consulted the documentation but couldn't manage to discover the signification of the constants, like QUERY_WAIT_INTERVAL, PROBE_THROTTLE_COUNT, etc.
I want to know the default frequency with which the announcer machine sends service announcements. I noticed also a DNS_TTL that was described as follow "The default TTL is set to 1 hour by the standard, so a record is going to stay in the cache of any listening machine for an hour without need to ping the server again". I have understood that it is the Time To Live of the service to stay in the DNS cache, but I couldn't understand what is intended by "purge the server". Does it mean that the listener has to ask the announcer about a service when the DNS_TTL expires? if so, why do need to have the announcer announce its service every 1 s (ANNOUNCE_WAIT_INTERVAL = 1000 milliseconds)?

I am so confused.. and would be grateful if anyone can guide me..