Abstract: An optical cable incorporates at least one fibre with positive dispersion and at least one fibre with negative dispersion spliced together within the cable. In the simpler forms of the invention, the aggregate dispersion from end to end of the cable is close to zero. The cable is intended for use in repairing a dispersion-managed optical cable installation in circumstances where it is not possible to replace a short damaged lenght of cable along its original route and it is necessary to insert such additional lenght of cable that the dispersion balance of the system may be adversely affected. If required, the cable may be modified (with an aggregate dispersion different from zero) to make it possible to match the dispersion of the damaged cable length that was removed instead of neglecting it.