The International Engineering Consortium provides an excellent website with good tutorials on all communications standards, speeds and technologies. Their main page is located at http://www.iec.org/ and their main tutorials page is located at http://www.iec.org/tutorials/

Synchronous Optical Network (SONET) SONET is a standard for connecting fiber-optic transmission systems, it is now an ANSI standard OC-n Optical Carrier Optical Carrier values are always a multiple of OC1, which is 51.85 Mb/s, so an OC-3 is 3 times OC-1. OC-1 51.85 Mb/s OC-2 103.70 Mb/s OC-3 155.55 Mb/s OC-9 466.65 Mb/s OC-12 622.20 Mb/s OC-24 1.2444 Gb/s OC-48 2.4888 Gb/s OC-192 9.9552 Gb/s

Copper data transmission speeds DS-0 64 Kb/s Digital Signal - DSO is an old Pulse Code Modulation standard (it is also the same speed as a standard telephone line) T-1, DS-1 1.544 Mb/s   E-1 2.048 Mb/s European standard DS-1c 3.152 Mb/s   T-2, DS-2 6.312 Mb/s   E-2 8.448 Mb/s European standard E-3 34.368 Mb/s European standard T-3, DS-3 44.736 Mb/s

xDSL min From max To ADSL and SDSL are the most common Digital Subscriber Line services, others exist such as HDSL, RADSL but they are not common and generally not implemented. ADSL - transmit 16Kb/s 640Kb/s   ADSL - receive 1Mb/s 9Mb/s Asychronous or Asymmetric Digital Subscriber Line SDSL 3 Mb/s   Symmetric Digital Subscriber Line

Ethernet speeds   Fast Ethernet 100 Mb/s   CDDI 100 Mb/s Copper Data Distribution Interface - a network capable of carrying 100Mb/s over Unshielded Twisted Pair (UTP) cable. FDDI 100 Mb/s Fiber Distributed Data Interface - set of ANSI protocols for sending digital data over fiber.

ISDN   Integrated Services Digital Network Base ISDN 64 Kb/s The base speed for ISDN is 64Kb/s, however ISDN channels can be combined (multiplexed) together to offer higher data rates, in multiples of 64, but generally in pair multiples (128Kb/s) B-Channel 128 Kb/s