DNS Entry Maximum TTL

DNS maximum time to live (TTL) is user-configurable and complies with RFCs 1035 and 2181.

One can set the DNS maximum TTL on the Oracle Communications Session Border Controller permitting the DNS entry information to be held until that time is exceeded. One can specifiy the dns-max-ttl parameter per network interface and/or to support the DNS ALG feature. The default value is 86400 seconds (24 hours). When the Oracle Communications Session Border Controller configured maximum value has been exceeded, the DNS TTL value is set to the configured maximum and a log entry is written. Otherwise the Oracle Communications Session Border Controller honors the lower value in the DNS response. The Oracle Communications Session Border Controller restricts all DNS entries minimum TTL value of 30 seconds, which the system's implementation of SIP requires.