ISDN protocol stack


  • Platform-independent architecture
  • For embedded and PC-based systems
  • Powerful CAPI interface

ISDNCode+ is a portable ISDN protocol stack developed and maintained by Stollmann E+V GmbH. It has been ported to many embedded and PC-based systems and supports various ISDN chipsets, CPUs and operating systems.

The stack consists of the D- and B-channel protocol supporting all ISDN functions for Basic Rate (BRI, S0) and Primary Rate (PRI, S2m) lines. All modes (NT, TE) are supported. Hardware driver for all ISDN chips on the market are available. Please refer to the feature list for more details.

The application interface of the stack is an enhanced CAPI 2.0. If required support for legacy interfaces like AT-commands is available.

The operating system interface (OSIF) makes integration into different platforms simple without altering the stack itself.

Supplementary Services
  • Multiple Subscriber Number (MSN)
  • Direct Dialing In (DDI)
  • Sub addressing  (SUB)
  • Calling Line Identification Presentation  (CLIP)
  • Calling Line Identification Restriction  (CLIR)
  • Connected Line Identification Presentation  (COLP)
  • Connected Line Identification Restriction  (CLIR)
  • Advice of Charge  (AOC-D, AOC-E)
  • Call Waiting  (CW)
  • Call Hold  (CH)
  • Call Retrieve  (CR)
  • Explicit Call Transfer  (ECT)
  • Three Party Conference  (3PTY)
  • Call completion on Busy Subscriber  (CCBS)
  • Call completion on No Reply  (CCNR)
  • Call deflection  (CD)
  • Malicious Call Detection  (MCID)
  • Call forwarding unconditional  (CFU)
  • Call forwarding busy  (CFB)
  • Call forwarding on No Reply  (CFNR)
  • User to User Signaling  (UUS)
  • Terminal Portability  (TP)
  • Message Waiting Identification  (MWI)
  • (MMC)