T-3 or DS-3

DS-3 speed differ internationally:

The T-3 North American speed is 44 mb with 672 channels (28 x 24 = 672) - the equivalent of 28 T-1s

The Japanese flavor, J-3, has 32 mb with 480 channels - the equivalent of 20 T-1s

The E-3 speed is 34 mb over 480 channels - the equivalent of 16 E-1s

DS-3 is also offered at fractional speeds, however customers that need speeds of, for example, 10 mb or 100 mbps are starting to opt for Gigabit Ethernet because of its flexibility in upgrading speed without changing equipment and lower prices for higher speeds.

DS-3 applications: Internet Access and Private Networks
DS-3 service is used mainly for private networks and Internet access. An organization's small sites often access the Internet using the T-3 circuits located at headquarters. This is an example of a hub and spoke configuration in which the headquarters acts as the hub for smaller sites.
DS-3 is also used in large, private networks operated by conglomerates for data communications between sites. They use these links for access to corporate databases and updates on transactions in, for example, large organizations that supply transportation and delivery services. ISPs and small carriers also use T-3 to access the Internet and for connections to other carriers.

T-3 services, the equivalent of 28 T-1 circuits, start to cost less than multiple T-1s when customers have eight to ten T-1s at the same site.