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4.4. Security
According to its mission Deutsche Welle contributes to the view of Germany in foreign countries. The content
of the services therefore has a somewhat official image so that its integrity has to be ensured. On the other
hand the Internet isn't secure today. Thus, considerable security efforts has to be undertaken.
Placing DW's server machine on a separated network protected by a firewall [Fig. 1] allows us to use IP
filtering and access lists to enhance security [Chapman 92]. To improve the security of our services even
further we used some host and network security scanners [SATAN 95]. We also permanently monitor the
activities of the machine in order to detect any unusual behaviour which might be a clue to hacker activities. In
addition for the ISDN connection between DW and GMD additional filtering for protocols, ISDN numbers of
the sending and receiving sites etc. are activated. GMD's internal networks are also secured by additional
security mechanisms. Thus DW's net is secured against attacks from the Internet and the server machine as
vice versa GMD against attacks from the server machine and over the ISDN connection.
4.5 How to Make Money Out of it
DW's first intention was not to make but to save money by its Internet activities. Instead of sending program
schedules via ordinary mail to recipients all over the world users can access these information on-line by
WWW or download them via FTP. Beside the cost savings for Deutsche Welle customers get a much faster and
more actual access to the data.
By analysing the server's log files, the usage of the information and the accesses per country and language can
be determined quit easily 1 . One must know that it is not possible for international radio and TV broadcasters to
get real numbers about their listeners and viewers and by that about the acceptance of their program. But this
information is absolutely necessary to adapt the content properly to the users' needs.
In addition, Deutsche Welle profits from a synergy effect, e.g. by the co-operation and the exchange of material
between its different branches and editorial departments and by advertising for each other. Last but not least,
Deutsche Welle is funded by the Federal Ministry of the Interior and due to this financial backup a short term
return of investment has not to be their most important goal. But nevertheless Deutsche Welle is currently
thinking about requesting money for special services like e.g. access to their archives.
5. Experiences
In our co-operation with DW we made several experiences about quality characteristics of Web servers and
training novice users of the Internet.
5.1. Statistics
Statistics are important for the Deutsche Welle as well as for GMD. Our contractor has to report on the results
of the co-operation and has to justify the investment in Internet internally. GMD uses these numbers for quality
control, monitoring and capacity planning.
Figure 2 shows the usage of the different services since the beginning. The most important service for
Deutsche Welle is the Web server. During the first months the number of requests was rather stable - around
350000. Since October 95 parts of the program of the Süddeutsche Zeitung, one of the most popular German
newspapers, are located on the Deutsche Welle server too. As a result the number of requests grows up to
600%.
FTP and email services were installed at the begin of 1995. Compared with the Web server the utilisation of
FTP and email is small. The total traffic in June '96 was 6.2 GB, 6 GB for Web traffic and only 140 MB for
FTP and 9 MB for email. Despite the low traffic volume email is important for Deutsche Welle to get feedback
from its Web readers and its radio and television audience. It is also important for GMD and gekko to get end
user error messages.
[ 1] Although by the use of cache servers these numbers don‘t represent the overall usage.