13.21 Gbps    OC-255  
10 Gbps       OC-192  
4.976 Gbps    OC-96  
2.488 Gbps    OC-48, STS-48  
1.866 Gbps    OC-36  
1.244 Gbps    OC-24  
933.12 Mbps   OC-18  
622.08 Mbps   OC-12, STS-12  
466.56 Mbps   OC-9  
155.52 Mbps   OC-3, STS-3  
100 Mbps      CDDI, FDDI, Fast Ethernet, Category 5 cable  
51.84 Mbps    OC-1, STS-1  
44.736 Mbps   T-3, DS-3 North America  
34.368 Mbps   E-3 Europe  
20 Mbps       Category 4 cable  
16 Mbps       Fast Token Ring LANs  
10 Mbps       Thin Ethernet, category 3 cable, cable modem  
8.448 Mbps    E-2 Europe  
6.312 Mbps    T-2, DS-2 North America  
6.144 Mbps    Standard ADSL downstream  
4 Mbps        Token Ring LANs  
3.152 Mbps    DS-1c  
2.048 Mbps    E-1, DS-1 Europe  
1.544 Mbps    ADSL, T-1, DS-1 North America  
128 Kbps      ISDN  
64 Kbps       DS-0, pulse code modulation  
56 Kbps       56flex, U.S. Robotics x2 modems,  
33.6 Kbps     56flex, x2 modem communications rate  
28.8 Kbps     V.34, Rockwell V.Fast Class modems  
20 Kbps       Level 1 cable, minimum cable data speed  
14.4 Kbps     V.32bis modem, V.17 fax  
9600 bps      modem speed circa early 1990s  
2400 bps      modem speed circa 1980s  

Units of Measurement
bit   = smallest unit of digital information, i.e. ones & zeros
byte  = a set of bits
bps   = bits per second
Kbps  = kilobits per second =1000 bits per second
Mbps  = Million bits per second =1,000,000 bits per second
Gbps  = Gigabits per second = 1,000,000,000 (one billion) bits per second
Tbps  = Terabits per second = 1,000,000,000,000 (one trillion) bits per second
(Network speed is mesured in 1000 units, memory and storage space in 1024 units)