Telephone Company WAN Technologies: Leased Lines
In a leased line solution for your Wide Area Network (WAN), you purchase from the telephone company (or lease — surprise!) a permanent link while paying a monthly fee. In this case, you are not charged by the connection or the amount of data; instead, once you lease the line, you can send as much data over the link as the link will support.
The permanent link is to your service provider’s network, and it is sometimes referred to as a point-to-point link.
Leased lines tend to have more available bandwidth than circuit switch solutions. The main examples of these solutions in North America are T1 and T3 links.
T1 link: These links are made up of 24 channels that carry data at 64 Kbps, yielding a total bandwidth of 1.544 Mbps. Unlike PRI lines, they do not require a signaling channel. As mentioned, you can have up to 24 channels.
When installed, the link will have all 24 channels, but when you pay for your service, you can pay for, or use, only a portion of this link. This option lowers your monthly cost and is called a fractional-T1 link.
T3 link: These links offer additional channels. This option uses 28 T1 lines that are combined and yields a total bandwidth of 44.736 Mbps.