170 / 176Siemens Web server OZW772... V6.0 CE1C5701enBuilding Technologies Appendix 2015-10-12Static IP address Network devices, and servers in particular, integrated permanently in a network,have static IP addresses. Clients often have a dynamic IP address. Web Server(integrated permanently in a network) has a static IP address and can thus bereached easily by clients.Subnet A subnet subdivides a network into smaller network segments.Subnet mask A subnet mask masks the IP address, i.e. it determines which parts of the IPaddress form the network number and which parts the computer number (e.g.server).Subnet mask 255.255.255.0 means that the first three sections of the IP addressdetermine the network number, and the fourth section is used for the computernumber. In this case, the first three IP address sections are identical for allnetwork devices. Example:Subnet mask 255.255.255.0 masks IP addresses: 192.168.1.1…192.168.1.254.Please note: Do not use the first IP address 192.168.1.0 and last IP address192.168.1.255.Switch A switch, similar to a hub, is a connecting element to connect various networksegments or network devices. Contrary to the hub, a switch is an intelligent deviceused to route packages only to the subnet or network device for which a packageis destined.TCP The TCP protocol is a TCP/IP protocol. TCP is responsible for transporting databetween two communication partners (applications). TCP is a securedtransmission protocol, i.e. a connection is established, monitored anddisconnected to data transmission.TCP is a so-called connection-oriented protocol. The transmission control protocolTCP reassembles the data packages, sent by the Internet protocol IP via differentnetwork connections, in the right order at the Receiver.TCP/IP Family of protocols used as the basis for the Internet. TCP/IP for the basis forany number of internet services such as HTTP (Web), FTP (file transfer) andSMTP (mail).TLS TLS (Transport Layer Security, for [outdated]: SSL Secure Sockets Layer)a hybrid encryption protocol to transmit data over the Internet. TLS 1.0, 1.1 and1.2 are standardized developments of SSL 3.0 (TLS 1.0 is now used for SSL 3.1).In other words, SSL is being further developed under the name TLS.The Web Server always uses TLS for e-mails if the e-mail provider supports TLS.Transmission ControlProtocolSee TCP.Transport LayerSecuritySee TLS.UDP UDP is a TCP/IP protocol to control data traffic between two communicationpartners (application). UDP, in contrast to TCP, is an unsecured protocol. UCP isa so-called connection-less protocol. Data packets are broadcast. The Receiver isresponsible for receiving data. The sender does not receive notification if the datapackages were received.