Standards for T1 and E1 WAN have been around for a very long time. T1 stands for T-Carrier Level 1 and describes a line that uses TDM, which consists of digital signals associated with different channels based on time. T1 is a standard often used in the following geographical regions:
- North America
- Japan
- South Korea
T1 operates using 24 separate channels at a 1.544Mbps line rate, thus allocating 64Kbps per individual channel. You can use the 24 channels any way you want to, and you can even buy just a few channels from the service provider based on your needs. In general terms, consider a T1 connection a trunk/bundle carrying 24 separate lines.
E1 (E-Carrier Level 1) is a standard similar to T1 but it is used exclusively in Europe. The main difference between E1 and T1 is that E1 uses 32 channels instead of 24, also operating at 64Kbps, thus offering a total line rate of 2.048Mbps. E1 also functions based on TDM, just like T1, so all other functionalities are common between the two standards.