Network Service Access Point

from Wikipedia, the free encyclopedia

According to ITU-T X.115 (1995), a Network Service Access Point ( NSAP ) is the information that a provider of an OSI Network Service needs to identify a specific service access point . It is usually used to address a computer or computer program or, in general, a terminal , the NSAP representing an address that is structured according to certain rules.

The NSAP address (also called ATM address) has a variable length that can be set up to a maximum of 20 bytes, which corresponds to 40 decimal digits. Bytes 1–13 form the network part and bytes 14–20 form the user part.

There are currently three different address formats:

  • DCC: Data Country Code
  • ICD : International Code Designator
  • E.164 : ISDN number

A terminal can have several NSAPs.

NSAP addresses are generally in the regime of ISO , which delegates the assignment to national standardization organizations. One of the schemes according to which NSAPs are formed is the numbering scheme according to ITU E.164 , which regulates the formation of international telephone numbers .

literature

  • Peter Welzel: Remote data transmission. Introductory basics for communication in open systems, Friedrich Vieweg & Sohn Verlag, Wiesbaden 1986, ISBN 978-3-663-00129-4 .
  • Gerhard Helge Schildt, Daniela Kahn, Christopher Kruegel, Christian Moerz: Introduction to Technical Computer Science. Springer-Verlag, Vienna 2003, ISBN 978-3-211-83853-2 .
  • Peter Bienert: Information and Communication. Technology and application in business and media, Springer-Verlag, Berlin / Heidelberg 1998, ISBN 3-540-64057-6 .
  • Dirk Traeger: LAN practice of local networks . Springer Fachmedien, Berlin / Heidelberg, ISBN 978-3-519-06189-2 .
  • Uwe Ring: "Network Technology Manual". Markt + Technik Verlag, Munich 2001, ISBN 3-8272-6080-9 .