Trunk Side A Central Office Switch connection that is capable of, and has been programmed to treat the circuit as, connecting to another switching entity, for example, to another carrier’s network. Trunk side connections offer those transmission and signaling features appropriate for the connection of switching entities and cannot be used for the direct connection of ordinary telephone station sets.
DNS name server availability Refers to the ability of a public-‐DNS registered “IP address” of a particular name server listed as authoritative for a domain name, to answer DNS queries from an Internet user. All the public DNS-‐registered “IP address” of all name servers of the domain name being monitored shall be tested individually. If 51% or more of the DNS testing probes get undefined/unanswered results from “DNS tests” to a name server “IP address” during a given time, the name server “IP address” will be considered unavailable.