2
Method of operation
gas-net
C1 and C2
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Re 3) TCP (computer network)
The TCP connection type is intended for applications which use a TCP/IP net-
work for the transmission of DSfG data. The easiest way is to imagine this oper-
ating mode without the modems and telephone network and with an IP network
instead. Only the hardware is exchanged and telephone numbers are replaced
by IP addresses. The connection remains being a dial-up network (between any
IP address of the network and the IP address of the RDT). Like in case of the
telephone dial-up network the connection set-up may be initiated by the center
or local RDT.
In addition to the IP addresses of RDT and center, the values for the subnet
mask and gateway usually used in the IP world and the port to be used for the
transmission are special parameters of the TCP connection.
In case of this operating mode the preferred service for time synchronization
would be NTP, which is a common network service.
A center that also supports DSfG queries via TCP/IP network is required for this
operating mode; e.g. GW-.
The use of the TCP/IP network is advantageous for applications provided with a
nearby IP network. In this case modem and telephone network can be saved.
