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  • one on US ANSI (American National Standards Institute) Designations.
  • another on European Designations.

Hope they prove to be useful to you.


Digital Signal Level Transmission Throughput
Digital Signal Level Throughput Notes
DS0 64 Kbps 1 T1 Channel
DS1 1.544 Mbps 1 T1 (24 DSO's)
DS1C 3.152 Mbps 2 T1's
DS2 6.312 Mbps 4 T1's
DS3 44.736 Mbps 28 T1's
DS4 274.176 Mbps 168 T1's

DS1's are commonly referred to as T's - T Spans - T1's.
The technology may be ported to Copper, Fiber or Wireless Transport media. T1's may be dedicated to voice, data or video transmissions or to channelized combinations of all.



Digital Signal Level Transmission Throughput
European (CCITT or ITU)
Digital Signal Level Throughput US Equiv.
E1 2.048 Mbps 1 T1
E2 8.448 Mbps 4 T1's
E3 34.368 Mbps 16 T1's
E4 139.264 Mbps 64 T1's

It should be noted that the CCITT (Consultative Committee for International Telephony and Telegraphy) or the ITU (International Telecommunications Union) recognize DS0 through DS4 Signaling Levels.