Network Communication Speed Comparison Table

Theoretical Throughput	Type of Service
28.8 kbps	Plain Old Telephone System (POTS)
56 kbps	Switched 56
56 kbps - 34 Mbps	Switched Multimegabit Data Service (SMDS)
64 kbps	Integrated Services Digital Network (ISDN)
64 kbps	DS0
128 kbps	ISDN Dual Channel
230.4 kbps	LocalTalk
640 kbps / 6 Mbps (upstream/downstream)	Asymmetric Digital Subscriber Line (ADSL)
720 kbps	Bluetooth wireless PAN (2.4 GHz band)
1 and 2 Mbps	IEEE 802.11 wireless (2.4 GHz band)
1 Mbps	Cable Modem
1.544 Mbps	DS1/T1
2 Mbps	PCS Wireless
2.048 Mbps	E1
6.312 Mbps	DS-2/T2
8.448 Mbps	E2
10 Mbps	10Base-T Ethernet
11 Mbps	IEEE 802.11b wireless Wi-Fi (2.4 GHz band)
12 Mbps	Universal Serial Bus (USB)
20-24 Mbps	U-NII Wireless
25.6-155.52 Mbps	Asynchronous Transfer Mode (ATM)
34.368 Mbps	E3
40 Mbps (5 MBps)	SCSI-1
44.736 Mbps	DS3/T3
51.84 Mbps	OC-1/STS-1 Synchronous Optical Network (SONET)
54 Mbps	IEEE 802.11a wireless WLAN (5 GHz band)
54 Mbps / 11 Mbps	IEEE 802.11g wireless WLAN (2.4 GHz band)
80 Mbps (10 MBps)	Fast SCSI
100 Mbps	100Base-T Ethernet (Fast Ethernet)
155.52 Mbps	OC-3/STM-1
160 Mbps (20 MBps)	Fast Wide SCSI
160 Mbps (20 MBps)	Ultra SCSI
274.176 Mbps	DS-4/T4
320 Mbps (40 MBps)	Wide Ultra SCSI
400 Mbps	FireWire (IEEE 1394A)
466.56 Mbps	OC-9/STM-3
480 Mbps	USB 2.0
622.08 Mbps	OC-12/STM-4
640 Mbps (80 MBps)	Wide Ultra2 SCSI
800 Mbps	FireWire 800 (IEEE 1394B)
800 Mbps (100 MBps)	ATA/100 (parallel)
1 Gbps	Gigabit Ethernet
1.244 Gbps	OC-24/STM-8
1.280 Gbps (160 MBps)	Ultra160 SCSI
1.280 Gbps (160 MBps)	Ultra3 SCSI
1.5 Gbps	Ultra Serial ATA 1500
1.866 Gbps	OC-36/STM-12
2.488 Gbps	OC-48/STM-16
2.560 Gbps (320 MBps)	Ultra320 SCSI
4.976 Gbps	OC-96/STM-32
9.953 Gbps	OC-192/STM-64
10 Gbps	10G Ethernet (IEEE 802.3ae)
13.271 Gbps	OC-255
40 Gbps	OC-768

Quick Glossary

kbps	kilobits per second. (kilo* = thousands)
Mbps	Megabits per second. (Mega = millions)
MBps	Megabytes per second. (Mega = millions)
Gbps	Gigabits per second. (Giga = billions)
OC-n	[Optical Carrier] A basic unit defined in increments of 51.84 Mbps (OC-1/STS-1 speed), where n is a multiple of that unit. Uses optical fiber network.
STM-n	[Synchronous Transfer Module] A basic unit defined in increments of 155.52 Mbps (OC-3/STM-1 speed), where n is a multiple of that unit.
STS-n	[Synchronous Transfer Signal] Similar to OC-n but uses electrical network.
SCSI	Small Computer System Interface

Note: In the Information Technology field, the lowercase "k" is used to describe decimal kilobits usually used in networking (e.g, 28kbps = 28 10^3 bps = 28,000 bps), whereas the uppercase "K" describes binary kilobytes usually used with memory capacity (e.g, 1 KB = 1 * 2^10 bytes = 1024 bytes) .
On a side note, although 8 bits (b) equals one byte (B), some hard disk manufacturers rate their drives using decimal Megabytes (e.g, 1 MB = 1 x 10^6 bytes = 1,000,000 bytes).