A business T1 circuit is carried through two twisted pairs of copper wires. Virtually, all residences and businesses currently have two pairs of copper wires running to them. T1 lines are capable of delivering 1.54 Mbps simultaneously in both directions (both upload and download), one direction for each pair of copper lines. Because T1 circuits are repeater driven (signal is digitally reestablished every 6000 feet), it is available virtually everywhere. The price however is affected by distance from the provider’s point of presence (POP), and number of times the signal must be reestablished. When the signal is reestablished, it is perfectly duplicated at near the speed of light, so signal quality is not lessened by distance. However, because there is cost each time the signal must be reestablished and for the facilities used for the distance from PoP the signal must be carried, business T1 circuit price quotes are generally significantly higher for locations which are remotely located. T1 lines are dedicated, in that they are not shared like DSL or cable, always connected, and are extremely stable. Most reputable providers include service level agreements (SLAs), which guarantee the reliability of their T1 circuits, with built in penalties for the provider if written reliability and circuit quality commitments are not honored. SLAs however can provide a false sense of security. Some of the tier 1 providers with the highest reliability and quality standards do not offer SLAs. In most cases, the penalties to the provider, included in SLAs for when circuits are down, or not working properly, do not come close to compensating for lost revenues which can result from circuit down time. For this reason, it’s more important to look at a company’s established record of circuit quality and reliability, than to go with a less reliable tier 2 provider, simply because they provide an SLA. Business T1 circuits can transfer data in many forms to accomplish a variety of functions. These include: fractional T1 (commonly 128 Kbps to 1024 kbps), burstable, integrated (one T1 line comprised of any combination the types of T1 listed here), channelized DS1 (a type of integrated T1, the other is dynamic integrated), point-to-point (direct private circuit between to locations), dynamic integrated, local (local phone service), PRI (voice service which includes many added features which cannot be provided by regular voice T1), and frame relay. Each of these types of DS1/T1 has advantages over the others, depending on the specific needs of your company. Also, the availability of each is based on the offerings of each T1 provider and the geographic proximity of the provider to your business.