ready 
ts 
ı be 
inst 
16 
- 813 = 
rated in different networks at signalling rates ranging from 50 bit/s to 48000 
bit/s and can be used for the solution of a data transport problem. Today more 
than 150000 data stations connected to different telecommunication paths are 
in operation within the Federal Republic of Germany. Data communication is pos- 
sible either over switched networks (Public Switched Telephone Network, DATEX 
Network, TELEX Network) or via fixed connections (Public Data Network for Fixed 
Connections). Each type of service has certain characteristic features which 
will not be discussed here. 
Since two years a public packet switched network, called DATEX-P, is in opera- 
tion, meeting specificly requirements for interactive transactions. 
This network has several international relations. Figure 3 shows the present 
outline 
F as com CON 
D PSS DATAPAC ) (INFOSWITCH (sin 
= 2 
       
  
  
M ^ 
NL DN1 -- - © pt 
C 2^" Japan (KDD) 
^? 
z^ 
Q: PEUT D 
AN 
| 
- NS se 
EIR 
8 EURONET as C e A 
(ser) TYMNET DK” “son 
i 
NL 
USA USA CH in operation 
fissure international. relations. .... ... Tr under preparation 
with DATEX-P 
  
  
  
Walter Tietz is currently Head of Section, Marketing 
of Data communication Services in the Technical Engineerinc 
Centre of the Deutsche Bundespost. He holds a degree in 
engineering and is working for the Administration since 
1952. He contributed to the work of CCITT, CEPT and ISO. 
  
Tietz 4