Appendix D. Glossary
61200290L1-1 MX2800 User Manual D-11
WAN
wide area network. A communications network serving geographically separate
areas. A WAN typically extends a LAN outside the building to link to other
LANs over telephone lines.
yellow alarm
A T3 yellow alarm is an indication sent back toward the source of a failed trans-
mit circuit in a DS3 two-way transmission path. The X-bits (X1 and X2) are set to
zero.