- ADTRAN, Inc. Modem User Manual

Appendix D. Glossary
D-12 MX2800 STS-1 User Manual 61200659L1-1
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.