Moving Bytes ISDN Support


The CAPI 2.0 stack from MOVING BYTES Communications includes drivers for all Windows platforms. All important B-channel protocols and the European D-channel protocol are supported. The CAPI driver is available in binary or ANSI-C source code. As a benefit from the usage of the ISO OSI driver model the driver can easily be adapted to other hardware platforms. The CAPI driver includes the following:

  • Hardware Layer - support for most of the Cologne Chip AG  ISDN chips:

  • VxD for Win95,Win98 with PnP and APM 1.1

  • Kernel mode driver for NT 4.0

  • Windows Driver Model support for Windows 98, Windows ME, Windows 2000, Windows XP, On Now (ACPI) and PnP compatible

  • Symmetric Multi-Processor support
  • CAPI 2.0 interface through 16-bit capi20.dll and 32-bit capi2032.dll

  • NDIS WAN miniport interface

  • (E)DSS1 Layer 2 - TEI management

  • (E)DSS1 Layer 3 - Transaction Control

  • B-channel Layer 2: HDLC, transparent, X.75 SLP, V.110

  • B-channel Layer 3: transparent, T.70NL/T.90NL, V.120, ISO8208

The CAPI driver was compatibility tested with several communication programs, including the softfax and softmodem features of the popular communication package RVS-COM.

ISDN Protocols

MOVING BYTES Communications also sells D- and B-channel protocols, which speeds up development of your products. Of course, MOVING BYTES Communications also offers training for these protocols, or fitting them for your needs. Here is a brief list of the protocols we sell:


The (E)DSS1 protocol stack is a Layer 2 and Layer 3 software module approved by an official ISDN test lab. It is designed to fit easily in almost all software and hardware environments. To achieve this goal the entire stack is written in ANSI-C and is strictly divided in platform independent and operating system specific modules. If required, MOVING BYTES Communications offers to do the whole port of the software to the new hardware architecture. The D-channel protocol stack contains: Hardware Layer - parallel support of more than one HFC-SP+chip. (E)DSS1 Layer 2 - TEI management. (E)DSS1 Layer 3 - Transaction Control. To support other ISDN hardware only the hardware layer needs to be changed.


The V.110 protocol is used as a layer 1 protocol in the B-channel. It allows for bit-rate adaptation. The MOVING BYTES Communications V.110 protocol has the following features: Bit rates 2400, 4800,9600, 19200 and 38400 7 or 8 data bits, 1 or 2 stop bits odd / even / no parity X-bits for TA-TA flow control low CPU usage

X.75 SLP

The X.75 SLP protocol is the default layer 2 B-channel protocol for CAPI. It is used under ISO8208 and T.70NL / T.90 NL.


ISO8208 is a layer 3 B-channel protocol. It is similar to X.25, and sometimes called X.25 DTE-DTE. It´s main use is for Euro-Filetransfer (EFT). T.70NL / T.90NL T.70NL / T.90NL is a layer 3 B-channel protocol, used mainly for the German ´T-Online´ telecom service.

ISDN Development

Moving Bytes offers services in the field of ISDN and telecommunications development and application, like customer specific development and technical support. Furthermore, a set of products is readily developed, and available in forms ranging from source code to turn-key customer products.

ISDN Approval Services

To get approval for your (E)DSS1 ISDN product in Europe, you need to pass several tests at an official ISDN test lab. We offer to do the whole approval procedure for you, or give you assistance at the test site. Our services range from making pre-tests at the public line or the test lab, to customer specific software development. Our company has good relations to the international ISDN test lab ´TÜV Rheinland´, which also resides in Cologne. Please ask for more information.