This Recommendation provides an overview of generic aspects of linear protection switching. It covers protection schemes applicable to circuit-switched and packet-switched layer networks; e.g.@ optical transport networks (OTNs)@ synchronous digital hierarchy (SDH)@ asynchronous transfer mode (ATM) and Ethernet transport based protection schemes. Overviews of ring protection and dual node subnetwork (e.g.@ ring) interconnection schemes will be provided in other Recommendations.