Reference models - Services towards users (ISDN, ATM, LAN)

(Layers of OSI model belong to the users, too.)
This chapter is subset of the content of realized telecommunication services.

• Traffic services, service categories (broadband network, ATM)
  • CBR (Constant Bit Rate)
    constant bit rate (higher layer sends the bits to AAL with a flat rate) connection-based synchronous traffic (timing between resource and destination and connection are necessary), uncompressed voice or picture, support of peak rate cell traffic transmission
  • VBR-RT (Variable Bit Rate - Real Time)
    variable bit rate, real-time, connection-based synchronous traffic (timing between resource and destination and connection are necessary), living picture, support of peak cell rate traffic transmission, maximal burst traffic
  • VBR-NRT (Variable Bit Rate - Non Real Time)
    variable bit rate, non-real time connection-based synchronous traffic (timing between resource and destination and connection are necessary) video playback, multimedia, support of peak cell rate traffic, maximal burst traffic
  • ABR (Available Bit Rate)
    variable bit rate, connection-based asynchronous traffic (X.25, frame relay), support of peak cell rate traffic transmission, burst traffic
  • UBR (Unspecified Bit Rate)
    variable bit rate, asynchronous traffic without any connection (LAN, SMDS)

• Channel services
  • Singal transmission
  • Signaling transmission
  • Remote feeding

• Signal transmission services
  • simplex signal transmission
  • halfduplex signal transmission
  • full duplex signal transmission

• Bearer Services (Bearer Capability IE (ISDN))
  Set of parameters to be given by a user at the beginning of the connection setup
  • Information transfer capability - what kind of information can be forwarded on a bearer?
    • Speech - This service allows the usage of analogue line sections and speech compressing equipment in the network.
    • Unrestricted digital information - Transparent data transmission
    • Restricted digital information - Non-transparent data transmission
    • 3.1 kHz audio - forward the signal of an analogue fax machines. Usage of speech compressing equipment is not allowed!
    • Unrestricted digital information with tones/announcements
    • Video
  • Transfer mode
    • Circuit mode
    • Packet mode
      • connectionless (datagram) service
        There is no connection setup between terminals before the data exchange. Terminal must provide the arrangement of packets into order.
        • unacknowledged
          Data transmission could be:
          • point-to-point
          • multicast
          • broadcast
        • acknowledged
      • connetion oriented (virtual call (circuit)) szolgálat.
        Connection setup between the two terminals is necessary before data exchange.
        • PVC - Permanent Virtual Connection
          • VCC - Virtual Channel Connection
          • VPC - Virtual Path Connection
        • SVC - Switched Virtual Connection
    • Information transfer rate (Circuit mode)
      • 64 kbit/s -
      • 2 x 64 kbit/s -
      • 384 kbit/s -
      • 1536 kbit/s -
      • 1920 kbit/s -
      • Multirate (64 kbit/s base rate)
  • Teleservices
  • Supplementary Services - (ISDN)

• Quality of Service - QoS

  QoS is a concept in connection with traffic engineering.