Proxy means authorized representative or representative. Proxy servers provide indirect access to the network for systems that do not have direct access to the Internet. These can be systems or individual clients that are excluded from direct network access by a firewall for security reasons. This is to keep the corporate network structure and subscriber addresses hidden from users. The proxy server swaps the source addresses of the clients for those of the proxy server, so that network subscribers only see them.
A proxy server is a dedicated server that forms the interface between individual clients or the corporate network with various clients and the public network or the Internet. The proxy can filter out individual data packets from the data stream between the Internet and a local network using packet filters, thus helping to increase security. Proxies can also act as proxy firewalls by limiting access to certain servers and providing only certain services to clients. Thus, when access is gained through proxy servers, Internet services such as Telnet or certain websites may be disabled or blocked, and not all Internet resources may be available to the user.
In addition, a proxy server also works as a cache server and offers the Internet user faster access to websites because they are cached close to the client in the proxy server. This means that when a website is called up by the client, it is loaded directly from the proxy server and not from a remote web server. The disadvantage is that the cached data may already be outdated but not yet updated. This task is performed by the Network Element Control Protocol( NECP).