| Among the enterprises and even the services | | | | lower speeds, an example would be from 64 |
| providers the most popular technology for | | | | kbps to 512 kbps in increments of 64 kbps. One |
| connecting various branches is the T1 line. Of | | | | of the more common uses of such speeds in the |
| course the popularity stems from some inherent | | | | IP domain is generally over Frame Relay WAN |
| benefits of using this solution. T1 lines deliver | | | | services. |
| dedicated bandwidth and can be used for point to | | | | Other times there are some other enterprise |
| point links. They also allow servicing multiple rates | | | | requirements like credit card transactions and |
| through channelization and bonding. | | | | lottery gaming transactions that require lower |
| T1 links support a bandwidth of 1.544 Mbps and | | | | bandwidths of around 64 kbps. For such circuits |
| for most customers this is ample connectivity, | | | | too many times T1 lines are built from the |
| especially to remote branches. Generally the T1 | | | | aggregation point to the central office. A single T1 |
| lines are sent over copper cables to the end | | | | line is able to carry signals from each DS0 and |
| customer location. Depending on the technology | | | | concentrate them. |
| used there would be single pairs or dual pairs of | | | | The capacity of T1 is limited to 1.5 Mbps and it |
| copper cables used for the T1. | | | | cannot be increased. However with a unique |
| When it comes to application of T1 solutions, a | | | | technique called T1 bonding, higher rates can be |
| very popular one is the PRI. PRI is a voice | | | | achieved and delivered to customer as desired. |
| technology that allows binding 23 voice channels | | | | Right from 2 T1 lines providing 3 Mbps to 6 lines |
| into a T1 and using it to service multiple phone | | | | delivering 9 Mbps we can get rates in steps of 1.5 |
| numbers. These numbers are called DIDs. The PRI | | | | Mbps with each T1. |
| lines typically end on a PRI switch which is capable | | | | Thus it is clear that T1 lines are extremely |
| of handling the DID numbers. | | | | valuable for enterprises as well as service |
| The other solution which typically uses T1 | | | | providers. Customers can opt for rates as low as |
| connections is the IP related services. These | | | | 64 kbps to ones as high as 9 Mbps with the |
| services are delivered on a shared medium at the | | | | same technology. For service providers |
| core of the network. However the link from the | | | | channelization and bonding allows them support |
| customer location to the central office is generally | | | | the wide range of rates. |
| a T1 line. This line can further be channelized to | | | | |