-------------------------------------- | Introduction to NIC Bridge/Async | | from Eighth Layer Systems | -------------------------------------- The following is an introduction to the capabilities and features of NIC Bridge and NIC Async. The "engine" of NIC Async is a DOS or OS/2 device driver. This driver acts as if it controls an Ethernet or Token Ring network card and meets the NDIS version 2.01 specifications. Rather than controlling a network card, however, NIC Async controls a serial port or modem. By combining NIC Async drivers with NDIS protocols, such as 3Com NBP or Microsoft/IBM NetBEUI, these protocols can be used from remote sites to provide remote access to Microsoft Lan Manager or IBM Lan Server systems. NIC Async can be used with any NDIS protocol which can be tuned for low speed operation. Tuning information is provided for use of Microsoft/IBM NetBEUI and NBP at speeds from 2400 to 115,200 baud. The diagram below shows an example configuration for NIC Async. This configuration allows a remote DOS workstation to access an IBM Lan Server or Microsoft Lan Manager server via the NetBEUI protocol. Multiple protocol and multiple port configurations, while not shown, are also available. ------------------- ------------------- | DOS Workstation | | OS/2 Server | | Software | | Software | ------------------- ------------------- | | ------------- ------------- | NetBEUI | | NetBEUI | ------------- ------------- | | ------------- ------------- | NIC Async | | NIC Async | ------------- ------------- | | ------------- Fixed or Dialup Link ------------- | Modem |-----------/ /----------| Modem | ------------- ------------- NIC Async drivers are available for DOS and OS/2 PCs. These drivers offer many features to provide maximum speed. Highly optimized drivers are provided which take maximum advantage of the 32 bit instruction set of 386 and 486 CPUs. The OS/2 drivers offer two serial port access modes: a high speed "Direct Port" mode for IBM AT type serial ports as well as an "OS/2 File System" mode for any serial port with an OS/2 driver. NIC Async also takes full advantage of high speed 16550 "FIFO" serial port chips. These chips, when used with NIC Async, can reduce or eliminate serial port "overrun" errors which plague modern serial communications. They allow NIC Async to provide speeds of 115,200 baud in most environments, while reducing CPU load by a factor of up to 16 at any baud rate. These high speed chips are standard on all IBM PS/2s and can be retrofitted anywhere that IBM PC 8250 type or IBM AT 16450 type chips are socketed. They cost less than $ 20.00 and are highly recommended for use with NIC Async. NIC Async also provides optional compression, useful to 57,600 baud on 386 and 486 PCs. This has been observed to provide up to 2:1 compression when copying real-life text files. Unlike MNP compression, NIC Async compression is intelligent and will only send compressed packets. It will not expand packets. Compression may be manually enabled or disabled while on-line. NIC Async provides optional DES encrypted password validation to ensure that only authorized persons have access to your network. For higher security requirements NIC Async provides optional full-time full-packet DES encryption. Due to the use of highly optimized 32 bit 386 and 486 specific code, this is useful at up to 57,600 baud. Once connected and validated, this feature may be manually enabled or disabled while on-line. The NIC Async DOS and OS/2 drivers are identical and symmetrical in design. Any IBM compatible PC, whether DOS or OS/2, standalone or networked, workstation or server may initiate a call to, or answer a call from, another NIC Async equipped PC. Alone, NIC Async may be installed on a PC to provide remote access to that PC, most commonly a server. When combined with NIC Bridge, NIC Async can provide remote access and remote bridging to virtually any device on a Token Ring or Ethernet network. Like NIC Async, NIC Bridge provides DOS and OS/2 drivers that are identical and symmetrical in design. Highly optimized 32 bit versions of these drivers are also provided for 386 and 486 CPUs. In Ethernet environments NIC Bridge provides MAC layer bridging and is thus protocol independent. In Token Ring environments NIC Bridge provides IBM Token Ring source routing. This requires the use of a special high speed NDIS driver, supplied with NIC Bridge, which allows use of the IBM Token Ring Adapter in source routing bridge mode. NIC Bridge acts as an NDIS protocol driver and can be linked to two or more NDIS network card drivers. An example configuration is shown below. Local Ethernet and Token Ring bridging, while not shown, is also available. ------------------------------ | Dedicated DOS or | | OS/2 Bridge PC | ------------------------------ ------------------------------ | NIC Bridge Driver | ------------------------------ | | To Remote User ------------- ------------ ------------- | NIC Async | | Ethernet | Local Ethernet Network ----//-| Modem |----| Driver | | Driver |--------//------------- ------------- ------------- ------------ NIC Bridge also provides custom protocol and address filtering. This allows the reduction or elimination of bandwidth consuming broadcast packets. It can also be used to bar access to specified network protocols and devices for security or other reasons. NIC Bridge/Async is brought to you by Eighth Layer Systems in Ottawa, Ontario, Canada. Eighth Layer Systems is solely owned by Michael A. Reid. Version 1.1i of NIC Bridge/Async is free of licensing fees subject to the terms of a license agreement contained in the Readme.Doc file distributed with the software. All trademarks are the property of their owners. This includes, but is not limited to, the trademarks of 3Com, IBM and Microsoft. ------------------------------------------------------------------------------