ISDN Protocol Stack -- "C" Source Code

ISDN Software

TeleSoft International provides many WAN protocol software packages, including ISDN source code software and ISDN device drivers to accelerate development and conformance testing of your ISDN product. TeleSoft's software ISDN protocol stack provides the fastest path to market-ready ISDN products for manufacturers worldwide.

New! Multi-Level Precedence and Preemtion available.

Formerly known as Amlink or Amlink3, the TsLink3 ISDN stack has been fielded for over twenty years by hundreds of customers in thousands of products.

An ISDN stack is often referred to as a "Q.931 stack" or "Q.931 signaling stack" because Q.931 defines the basic rate ISDN and primary rate ISDN protocols. ISDN is sometimes called Digital Signaling System 1, or DSS1.

TeleSoft's TsLink Basic Rate and Primary Rate ISDN source code stacks are amongst the most proven and feature-rich software available today. In addition to DSS1, AutoSPID, Autoswitch Detection, NFAS, and D-Channel Backup, a wide range of conformance tested worldwide switch variants are available. Full NT and TE side support is included. Q.921 LAPD and LAPB can be licensed as either individual software modules or as an integrated stack

TeleSoft licenses well-proven software BRI and PRI source code for AutoSPID, Autoswitch Detection, NFAS, and D-Channel Backup in addition to DSS1 and other switch variants used worldwide. TeleSoft also supplies software for Voice Supplementary Services, also referred to as Q.932.

The TsLink3 ISDN software development toolkit is available in source code and is architected for applications, both embedded and host-based, in which performance and code size are important.

The TeleSoft ISDN SDK has available interfaces to several standard preemptive and non-preemptive real-time operating systems and non-real time operating systems, including ATMOS, Linux, MQX, Nucleus Plus, OSE, pSOS, TsRITE*, VRTX, and VxWorks

If a customer selects a different OS than one from the list above, one of the pre-ported OS interfaces can be used as a template to rapidly develop a new OS interface. TsLink3 customers have leveraged the OS-independent architecture to port to other operating systems including Solaris, Windows, and Proprietary operating systems

Integrated Systems Digital Network (ISDN) is a term that encompasses a large number of protocols, including Q.921/Q.931 Narrow-band ISDN (N-ISDN), both Basic Rate ISDN (BRI) source code and Primary Rate ISDN (PRI) source code; Q.2931 Broadband ISDN (B-ISDN); Q.922/Q.933 Frame Relay and other protocols. Usually when you hear ISDN, it means the N-ISDN set of protocols (e.g. Q.921, Q.931.)

PRI is used on a T1/E1/J1, and is often called "WAN protocol software", or "T1/E1/J1 signaling software" (as appropriate, often people are more specific and say "T1 signaling software" "E1 signaling software" or "J1 signaling software".)

Narrowband ISDN (N-ISDN) also two major Physical interfaces--the two B channel Basic Rate Interface (BRI) and the 23, 24 or 30 channel Primary Rate Interface (PRI). T1 lines may be channelized into 24 DS0 channels, one of which is used for the D channel (the signaling channel). Non-Facilities Associated Signaling (NFAS) allows two or more T1 PRI lines to share a single D channel (this is especially useful on a T3, which can be channelized into 28 virtual T1 lines.) E1 lines may be channelized into 32 DS0 channels, one of which is used for synchronization, one is used as the D channel (i.e. signaling channel) and the other 30 are used as bearer channels. TeleSoft provides software that implements an ISDN protocol stack that supports both Network and User sides of N-ISDN.

Q.931 ISDN defines both a network (NT) and a user (TE, or CPE) side, which define complementary parts of the ISDN state machine. Many countries have their own variations of Q.931 signaling to meet their unique needs. Most of the recent ISDN variants are "deltas", or variations, to the Euro-ISDN standard. TeleSoft's ISDN software development toolkit supports virtually all of the currently-used ISDN variants, and will support future ISDN variations as the are requested.

The QSIG protocol stack is compatible with the ISDN stack.

TeleSoft's Basic Rate and Primary Rate ISDN source code stacks are amongst the most proven and feature-rich available today. In addition to DSS1, AutoSPID, Autoswitch Detection, NFAS, and D-Channel Backup, a wide range of conformance tested worldwide switch variants is available. Full NT and TE side support is included. Q.921 LAPD and Q.931 LAPB can be licensed either individually or as an integrated stack

TeleSoft licenses well-proven source code for AutoSPID, Autoswitch Detection, NFAS, and D-Channel Backup in addition to DSS1 and other switch variants used worldwide. TeleSoft also supplies Voice Supplementary Services, also referred to as Q.932.

The TsLink3 ISDN software development toolkit is available in source code and is architected for applications, both embedded and host-based, in which performance and code size are important.

* TsRITE is a TsLink3 product, and is a compact, low-overhead RTOS customized for protocol and B-channel data requirements. It is royalty-free.

This Software is often called:

T1 signaling stack
T1 protocol stack
T1 signaling source code
T1 WAN protocol software
E1 signaling stack
E1 protocol stack
E1 signaling source code
T1 WAN protocol software
J1 signaling stack
J1 protocol stack
J1 signaling source code
T1 WAN protocol software

TeleSoft International is the original developer of the TsLink3 range of high performance WAN protocols including ISDN BRI and PRI, QSIG, CAS E1 R2, T1 RBS, AO/DI, ML-PPP, Frame Relay, X.25, and also a range of hardware reference designs. TsLink3 protocol source code is exceedingly well engineered - tightly coded for performance and compact footprint, with a quality that delivers rock-solid stability.

TeleSoft's foundations go back to 1986 when the first ISDN stack was released. Since then TeleSoft's protocols have been proven in use by more than 200 customers worldwide. World leaders, including AT&T, Cisco, D-Link, Digital Equipment, Fujitsu, IBM, Lucent, Matsushita, Multi-Tech, NTT, Polycom, and Vertical Networks have all used the source code for TeleSoft's proven protocol software.

Manufacturers license the source code for TeleSoft's proven Protocol Stacks and Reference Designs to get their products to market faster with minimized technical risk and development costs. TeleSoft focuses on developing the software and hardware so that you can focus on manufacturing and shipping your product.