S 5.22 Compatibility check of the transmission and reception systems

Initiation responsibility: Head of IT, IT Security Officer

Implementation responsibility: Specialists Responsible

Depending on the level of compatibility of the sending and receiving systems, information can be transferred fairly reliably by exchanging data media. There are different compatibility requirements depending on the complexity of the data to be exchanged. Before setting up a regular exchange of data media, the following must be examined to detect any incompatibilities in advance and eliminate them wherever possible:

• Physical medium:
  
  It is necessary, of course, for the sending and receiving systems to use the same physical storage media. However, mechanical equivalence alone is not enough since differences in parameters, i.e. in tape speeds, can also lead to problems.
• Character code (z. B. ASCII or EBCDIC):
  
  If the sending and receiving systems use the same character sets, then individual sectors or blocks, which may be distributed non-contiguously on the data medium, can be read physically in plain text. If the character sets are not identical, then the transmitted data will be interpreted incorrectly.
• Formatting the operating or file system of the data medium:
  
  If both systems also use the same operating and file system or the receiving system is able to read the formats of other operating systems (not all Unix operating systems are able to read NTFS-formatted data media), then all files can be reconstructed to their original form, i.e. to the same form as was available to the sender. This is adequate for information not requiring any further formatting, as is the case with most application programs (e.g. word processing programs).
• Application software:
  
  If application programs were used to generate the data to be transferred, then the versions of these programs must be checked to ensure they are identical since the file formats used might be different in different versions. The versions do not need to be identical when the program versions are upward or downward compatible.
• Security software and security parameters:
  
  If IT security products or the protection mechanisms available in certain application programs are used (see S 4.30 Utilisation of the security functions offered in application programs), then the compatibility of these products or protection mechanisms must be ensured.
  
  The sender and recipient must agree on which keys and passwords to use over a suitable route.

When incompatibilities arise, additional precautions or products must be provided to achieve the required conversion, or the corresponding equipment must be added to the sending and receiving systems.

Review questions:

• Is it ensured that compatible IT products are used both by the sender and the recipient?