Benzene is a widely used industrial chemical. Benzene is found in crude oil and is a major part of gasoline. Its used to make plastics, resins, synthetic fibers, rubber lubricants, dyes, detergents, drugs and pesticides. Benzene is produced naturally by volcanoes and forest fires. In homes, benzene may be found in glues, adhesives, cleaning products, paint strippers, tobacco smoke and gasoline.
A system call is an interface between a user-space application and a service that the kernel provides. Because the service is provided in the kernel, a direct call cannot be performed; instead, you must use a process of crossing the user-space/kernel boundary.
Call signaling is a process that is used to set up a connection in a telephone network.all signaling is used in voice over IP (VoIP) systems to establish connections between H.323 endpoints, or between an endpoint and a gatekeeper.