3153  Communication medium type code                          [C]

     Desc: Code specifying the type of communication medium.

     Repr: an..3

     AA    Circuit switching
              A process that, on demand, connects two or more data
              terminal equipments and permits the exclusive use of a
              data circuit between them until the connection is
              released (ISO).

     AB    SITA
              Communications number assigned by Societe Internationale
              de Telecommunications Aeronautiques (SITA).

     AC    ARINC
              Communications number assigned by Aeronautical Radio
              Inc.

     AD    Courier
              A communication channel identifying a courier.

     CA    Cable address
              The cable is used as communication medium.

     EI    EDI transmission
              Number identifying the service and service user.

     EM    Electronic mail
              Exchange of mail by electronic means.

     EX    Extension
              Telephone extension.

     FT    File transfer access method
              According to ISO.

     FX    Telefax
              Device used for transmitting and reproducing fixed
              graphic material (as printing) by means of signals over
              telephone lines or other electronic transmission media.

     GM    GEIS (General Electric Information Service) mailbox
              GEIS mailbox system is used as communication medium.

     IE    IBM information exchange
              IBM IE is used as communication medium.

     IM    Internal mail
              Internal mail address/number.

     MA    Mail
              Postal service document delivery.

     PB    Postbox no.
              Postbox system is used as communication medium.

     PS    Packet switching
              The process of routing and transferring data by means of
              addressed packets so that a channel is occupied only
              during the transmission; upon completion of the
              transmission the channel is made available for the
              transfer of other packets (ISO).

     SW    S.W.I.F.T.
              Communications address assigned by Society for Worldwide
              Interbank Financial Telecommunications s.c.

     TE    Telephone
              Voice/data transmission by telephone.

     TG    Telegraph
              Text transmission via telegraph.

     TL    Telex
              Transmission of text/data via telex.

     TM    Telemail
              Transmission of text/data via telemail.

     TT    Teletext
              Transmission of text/data via teletext.

     TX    TWX
              Communication service involving Teletypewriter machines
              connected by wire or electronic transmission media.
              Teletypewriter machines are the devices used to send and
              receive signals and produce hardcopy from them.

     XF    X.400
              CCITT Message handling system.