without your knowledge. The primary benefits of Frame Relay are cost and flexibility. A point-to-point T1 will cost more than a Frame Relay T1 link between two sites, especially if the sites are not in the same geographic location, or LATA. Also, with a point-to-point T1, 1.5 Mbps Frame Relay of dedicated bandwidth must be allocated between each point, regardless of the uti- lization of that bandwidth. In contrast, a Frame Relay link shares resources; on a Frame Relay link, if bandwidth is not being used in the cloud, other customers can use it. The notion of shared bandwidth raises some questions. What if someone else is using the bandwidth and you suddenly need it? What if you're using the bandwidth and someone else suddenly needs it? Frame Relay introduces the idea of the committed information rate (CIR), which helps address these concerns. Ordering Frame Relay Service When you order a Frame Relay link, telco needs to know four pieces of information to provision the circuit. One of these is the CIR. Here are the requirements: The addresses and phone numbers of the endpoints The street addresses-and, more importantly, phone numbers-in use at each endpoint are critical components of a circuit order. If the location does not have phone service, in most cases, it won't exist to telco. The port speed The port speed is the size of the physical circuit you will deliver to each end. These physical links do not have to be the same size or type, but they must both be able to support the CIR requested for the Frame Relay link. The port speed can be anything from a 56 Kbps DDS circuit up to and exceeding a DS3. These days, the most common Frame Relay handoff is a full T1, though fractional T1s are still used as well. It all depends on the cost of the physical circuit. The CIR The CIR is the rate of transfer that you want the carrier to provide. When requesting Frame Relay service, you specify the amount of bandwidth you want available, and the provider guarantees that, up to this level, all frames that are sent over this 