(1) A VTAM term for a list of routes through a network, arranged in an order of preference for their use.
(2) A set of link and node characteristics, associated with a session or a set of sessions, that determine the route that is selected for the sessions through an APPN network.
(3) A set of characteristics (such as route security, transmission priority, and bandwidth) used to construct a route between session partners. The class of service is derived from a mode name specified by the initiator of a session.
(4) In fibre-channel technology, a specified set of delivery characteristics and attributes for frame delivery.