having to go through the operator. PRI Primary Rate Interface An ISDN service that provides 23 64-Kbps B (Bearer) channels and one 64-Kbps D (Data) channel (23 B and D). Diff-Serv Differentiated Services The Diff-Serv model divides traffic into a small number of classes to provide quality of service (QoS). PSTN Public Switched Telephone Network The worldwide voice telephone network. DNIS Dialed Number Identification Service A telephone function that sends the
