transitive verbo·ver·sub·scribed, o·ver·sub·scrib·ing, o·ver·sub·scribes
oversubscribe - Computer Definition
To place potentially greater demands on a device or circuit than it is capable of handling at one time. A T1 circuit, for example, supports a data rate of 1.536 Mbps, which commonly is subdivided into 24 voice grade channels of 64 kbps. So, the circuit can support 24 voice or data calls of 64 kbps each. If more than 24 calls are offered to the T1, it is said to be oversubscribed. If the calls are all uncompressed voice calls truly requiring continuous bandwidth of 64 kbps, the 25th call must be denied. If the calls are data calls supporting bursty applications, such as e-mail, that do not require continuous bandwidth of 64 kbps, the TDM multiplexer may be able to manage the contention by buffering some of the data and sharing bandwidth among multiple such calls. Thereby, the circuit may be able to support considerably more than the 24 calls supported by a more rigid approach. Oversubscription is the economic foundation of carrier services. For example, a neighborhood of 96 phone lines may be served well by two oversubscribed T1 lines because the probability of all users placing calls at one time is very small (less than 1 percent). See also bandwidth, carrier, channel, circuit, and voice grade.