Avaya SBC supports an IP Office trunk originating from dynamic IP addresses. The external address of the ISP router or firewall at the remote site is based on Dynamic Host Configuration Protocol (DHCP). Therefore, a static external IP address is unavailable for configuration or installation.

Instead, in the server configuration for Remote Branch Office servers, you can administer an FQDN pointing to a Dynamic DNS record. If the TLS connection from the Remote Branch Office drops, Avaya SBC resolves the FQDN entry again for all Remote Branch Office servers. If the DNS record TTL value expires, Avaya SBC queries the DNS for all FQDN entries in the server configuration.