DeNovoLab provides two LRN server that your dnl_softswitch can query.
You can setup LRN server access via Configuration > System Setting page:
The two LRN IP provided by DeNovoLab are 188.8.131.52 and 184.108.40.206.
In the CDR or in call simulation, if you are getting LRN Not Available error like below, you need to check with DeNovoLab support to have your switch IP whitelisted:
If you have multiple IP addresses in your server, you may choose one of those IP addresses to be used for querying LRN from remote LRN server.
You can lookup the config file dnlsoftswitch.conf from <dnlsoftswitch base dir>/conf/dnl_softswitch.conf
Then, in the configuration inside, you can specify the local IP you want to be used by the dnl_softswitch to query LRN:
lrn_local_ip = x.x.x.x
lrn_local_port = 4319
lrn_support_heartbeat = yes
lrn_heartbeat_timeout = 10
lrn_heartbeat_interval = 2
lrn_t1 = 500
lrn_query_retry_count = 3