service provider (SP)

The term service provider exists in various contexts in the Open Systems Interconnection( OSI) layer model and as a service provider in the fixed and mobile networks.

1. In the OSI view, the service provider is always the lower- level layer that provides its service to the higher-level layer. The only layer that does not provide a service to a higher-level layer is the application layer. It is the only service user of its subordinate layer. Access to a service occurs at the service access point.
2. In the case of networks, a service provider is an independent company which, in addition to the actual operator, offers additional services to the customers of the networks in the form of services, maintenance or additional communications technology services. Service providers market telecommunications services to end customers on their own account without owning their own telecommunications networks or network components. They purchase services from telecommunications network operators and pass them on to their customers either slightly or unchanged. Under the Telecommunications Ordinance(TKV) of 1997, network operators are required to license suitable companies as service providers. Service providers
   

   and their services

   Among the service providers, there are those that offer IT services and infrastructural services such as B2B service providers and cloud service providers( CSP), others specialize in network or Internet services, such as the communication service providers (CSP), network service providers( NSP) and Internet service providers( ISP), others provide access to the Internet such as the Internet access providers ( IAP) or offer complete application solutions such as the application service providers ( ASP). Still others, such as the Full Service Providers( FSP), provide a wide range of Web-based services or work on a content-related basis, such as the Internet Content Providers( ICP). There are also various providers of security services and many other services.