plied to a process or protocol to create a path for data or information between disparate media. A link created with IEEE 802.2 logical link control (LLC) at layer 2 is at the highest layer of LAN architecture. It defines a set of protocols that support services between the media access layer and the transport layer. LLC is functionally equivalent to the telephone hook-switch and DTMF keypad used to control setup and teardown of a voice connection or link. Most LAN cards, and many other devices supporting LAN connections, have a green indicator light. If the light is illuminated, it indicates physical connectivity between two devices. Many tele- phones, especially those with two or more lines, have an indicator to show off-hook, active line, or in use. Most equipment with a wide area physical connection is equipped with some kind of indicator as well as alarm to indicate status of the link. CLOCKING CONSIDERATIONS Clocking and timing in the public network is based on four levels of accuracy, traceable to worldwide time standards. These highly accur- ate clocking sources are generically referred to as stratum 1 through stratum 4, where stratum 1 is the most accurate. Before 1984, the US portion of the network was primarily the responsibility of AT&T. Network clocking information was distributed throughout the net- work infrastructure whereby a single clock signal source was sent through the network hierarchy. The most accurate clock signal was distributed to a set of switches that passed it on to lower levels in the hierarchy with the lowest and least accurate clock signal reaching end office switches serving subscribers. This all changed in 1984 when the network was broken up into the seven regions and equal access to the long distance network PRACTICAL IP AND TELECOM FOR BROADCAST ENGINEERING AND OPERATIONS was declared. The seven regions were divided into 200 plus local access and transport areas (LATAs) where traffic originating and terminating in different LATAs had to be transported by the long distance carr