ut errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 1 interface resets 0 output buffer failures, 0 output buffers swapped out The delay for a multilink interface is five times that of a serial T1 interface. The bandwidth and delay values shown for an interface are representa- tive of the actual bandwidth and delay, provided they have not been modified. The bandwidth and delay values are configurable in IOS. The default values reflect the propagation delay well enough to illustrate the impact of multilink-PPP. Telecom Glossary LEC (pronounced leck) is short for local exchange carrier. A LEC is a phone company that provides local service, as opposed to an IXC, which interconnects LECs to provide long-distance service. Most of the largest LECs are RBOCs. Local loop The local loop (also referred to as the last mile) is the copper handoff for a cir- cuit from the telecom facility to your facility. While a T1 may be converted and multiplexed into a larger circuit like a DS3 or SONET circuit, the last mile is usually copper. Multiplexing Multiplexing is the act of taking multiple signals and sharing them on a single signal. The act of converting 24 64-Kbps channels into a single T1 is an example of multiplexing. PBX is the abbreviation for private branch exchange. A PBX is essentially a phone system as most people know it; it offers a phone network to an entity such as an enterprise. Some of the main features of a PBX are the ability for many phones to share a limited number of public phone lines, and the ability to number individual extensions with, typically, three- or four-digit extension numbers. PBX systems have traditionally been large hardware devices with cryptic control systems and proprietary hardware. VoIP is often controlled by software versions of PBXs. Examples include Cisco's Call Manager and the open source product Asterisk. POTS is short for the clever phrase plain-old telephone service. A POTS line is one into which you can plug