SDH		synchronous digital hierarchy
STM-1		155 mb/s (european SDH)
E1		2 mb/s (european SDH)
DS0		64 kb/s (american SDH)
DS1		24*DS0 (american SDH)
DS3		36*DS1 (american SDH)
BLSR		bidirectional line switched ring (SONET)
MSPring		multiplex section shared protection ring (SDH equivalent of BLSR)
UPSR		unidirectional path switched ring (SONET)
SNCP		subnetwork control protocol (SDH equivalent of UPSR)
DNI		dual node internetworking
DRI		dual ring interconnection
linear APS	linear automatic protection switching (SONET) either 1+1 or 1+n
MSP		multiplex section protection (SDH version of APS)
AU-(3/4/...)	multiplexor/demultiplexor to multiplex
		- STS-1 signals onto an STS-3 signal
		- AU-3's onto an SDH STM-1
SONET		synchronous optical network
OC-n		n*155/3 mb/s (SONET)