This document identifies the different methods of connecting Novell NetWare networks to TCP/IP-based internetworks. It exposes the limitations of past solutions and examines the benefits offered by the Cisco Internet Junction software.
In the past, providing Internet access to NetWare network users was a complicated and expensive proposition. IPX-based applications do not generally interoperate with TCP/IP-based applications, so historically, for a single workstation to connect to bo th IPX and TCP/IP-based services, the workstation required both an IPX and TCP/IP protocol stack installed. This is known as a dual-protocol solution. (See Figure 1.)
Figure 1: Dual-Protocol Solution
While a dual-protocol solution can be appropriate for some environments, users considering such a solution must evaluate the following issues:
The costs associated with the acquisition, installation, and maintenance of TCP/IP and Internet connectivity can be significant. When evaluating which solution to use, users must also consider the following:
The Cisco Internet Junction gateway is available today as a client/server software package. The server (or gateway) software operates on a PC running Microsoft Windows NT, and the client software supports such platforms as Microsoft Windows 3.1, Windows f or Workgroups, and Windows 95. Cisco Internet Junction software supports various WAN connections including dial-up, Integrated Services Digital Network (ISDN), Switched 56, T1/E1, and T3.
Because TCP/IP evolved as an open protocol, security is a greater concern in TCP/IP networks than in networks that use proprietary protocols such as IPX. Because the Internet Junction gateway effectively functions as a firewall solution, it establishes a high level of security at an affordable investment. IPX clients are not assigned individual TCP/IP addresses; therefore the NetWare network is effectively isolated from intruders attempting to gain access via the Internet.
In order to offer a complete, economical, and easy-to-implement solution, the Cisco Internet Junction gateway software comes bundled with Netscape Navigator software.
Cisco Internet Junction software operates as an IPX-to-TCP/IP gateway implemented in a client/server architecture. The software comprises two components: the server and the client executables.
The PC running the Internet Junction server components requires configuration of both the IPX and TCP/IP Protocols. Both protocols are standard and are shipped with Microsoft Windows NT Version 3.5. (S ee Figure 2.)
Figure 2: Internet Junction Server
Client Software
The client software component includes two files: WinSock.DLL and IJCLIENT.EXE. These files enable third-party TCP/IP applications that are compliant with WinSock version 1.1 to run over the IPX protocol. Examples of such applications include Netscape Nav igator, SAP, and Lotus Notes. (See Figure 3.)
Figure 3: Internet Junction Client
The Internet Junction WinSock.DLL was designed according to the Windows Sockets API (WinSock). This is a specification that solves most application compatibility problems. It provides a layer between Internet applications and the underlying TCP/IP communi cations stack. Software developers write applications that communicate directly with WinSock, and TCP/IP stack vendors write WinSock interfaces to their stacks. WinSock is only a specification, so there is no guarantee that every WinSock 1.1 application w ill operate in all situations. Specifications do not ensure compatibility.
The IJCLIENT.EXE file works in tandem with the WinSock.DLL to allow TCP/IP applications to run over IPX.
In order to provide increased flexibility, Internet Junction client software can be loaded either in the public folder of the NetWare server or on each client workstation.
Client applications using the Internet Junction gateway perform at approximately 90 percent of their native performance level. Any dissatisfaction with the performance of such Internet applications as Netscape Navigator is almost always because of inadequ ate bandwidth on the Internet WAN connection. Typically, the more WAN bandwidth available, the higher the degree of performance desktop users will experience.
Installation of the Internet Junction software is an easy process and offers NetWare users immediate access to internal TCP/IP-based resources. However, in order to provide access to the global Internet, a connection to an Internet Service Provider (ISP) must be established. The local telephone company must be contracted to provide an appropriate WAN line, for example dial-up, ISDN, or 56K. This WAN line will connect the internal network to the chosen ISP. Depending on the configuration, a router, PC card , or modem will be required to provide a connection to the WAN line. The ISP will provide users with IP addresses to install on their Internet gateway PCs. Two IP addresses per user will be needed if a router is used. Often an ISP will contract with the t elephone company for a WAN connection in order to provide an integrated solution. (See Figure 4.)
Figure 4: Connecting to the Internet
Cisco has announced a three-phase plan for the delivery of the Cisco Internet Junction gateway technology. Today, Cisco offers the Internet Junction gateway as a client/server software product. In order to make this solution available to the widest ran ge of users, Cisco intends to expand the range of choices available to network managers.
In early 1996, Cisco will offer a standalone, integrated Internet Junction gateway solution that will include both the hardware and software components of the Internet Gateway server. This turnkey solution will be offered in a number of fixed hardware configurations and will be based on the popular Cisco Internetwork Operating System (Cisco IOSTM) software. The Cisco IOS software provides a stable development platform, a wide range of internetworking op tions, and a simple and consistent user interface.
Later in 1996, Cisco will incorporate the Internet Junction gateway server software as an optional feature of the Cisco IOS software. By merging the functionality of the Internet Junction gateway into the Cisco IOS software, it will be possible to deli ver the Internet gateway functionality across a wide variety of hardware platforms. Users will be able to purchase the Internet Junction solution as an extra cost option to the Cisco IOS software.