Indefeasible right of use

Definition
An indefeasible right of use (IRU) is a contractual agreement between the operators of a communications cable, such as submarine communications cable or a fiber optic network and a client.

The IRU:

{{Quote|shall mean the exclusive, unrestricted, and indefeasible right to use the relevant capacity (including equipment, fibers or capacity) for any legal purpose. (full-text).

It refers to the bandwidth purchased after the submarine cable system has sealed the Construction and Maintenance Agreement (C&MA) among the owners or after the system came into service and where the unowned capacity is available. IRU may also be purchased from the existing owner.

The right of use is indefeasible, so as the capacity purchased is also unreturnable and maintenance cost incurred becomes payable and irrefusable. "IRU user" can unconditionally and exclusively use the relevant capacity of the "IRU grantor's" fiber optic network for the specified time period.

In plainer, but less accurate English, the purchase of an IRU gives the purchaser the right to use some capacity on a telecommunications cable system, including the right to lease that capacity to someone else. However, with that right comes an obligation to pay a proportion of the operating cost and a similar proportion of the costs of maintaining the cable including any costs incurred repairing the cable after mishaps. Companies that buy a leased line between say, London and New York do not buy an IRU &mdash; they lease capacity from a telecommunications company that themselves may lease a larger amount of capacity from another company (and so on), until at the end of the chain of contracts there is a company that has an IRU, or wholly owns a cable system.