As your business needs grow, chances are, so will your network. Explosive growth and constant change in the information management and delivery arena call for versatile technologies to meet your company's growing needs. IBM Communications Server for Linux meets the challenge -- offering a comprehensive package of enterprise networking solutions to effectively connect your employees, customers and trading partners across multiprotocol networks.

Power up for business flexibility
No matter where your company wants to go to make existing host applications available through the Internet, IBM Communications Server takes you there quickly and easily. With IBM Communications Server, you can leverage network assets already in place, while making the transition at your own pace. IBM Communications Server can connect your employees, customers and trading partners to the information and applications they need, independent of the underlying network

A natural evolution
IBM has long been a leader in communication software. With the introduction of Communications Server products, we've implemented functions and connectivity based on industry-standard solutions, tailored for a wide range of platforms. With the addition of IBM Communications Server for Linux, OS/2 Warp customers can enjoy increased confidence in considering the Linux operating environment for their future platform of choice. Acting as a multiprotocol gateway, IBM Communications Server enables applications to run over multiple network protocols.

Internet Networking
IBM Communications Server also works as a Telnet server, providing SNA network access to client applications running anywhere in your TCP/IP network. TN Redirector provides pass-through TCP/IP host access to TN3270, TN3270E, TN5250 and VT clients, referred to collectively as Telnet clients. The Telnet user communicates with Communication Server for Linux over a TCP/IP connection; Communications Server then communicates with the host over another TCP/IP connection. This allows you to use Secure Sockets Layer (SSL) security checking where necessary, and not on the entire user-to-host connection. Enterprise Extender, a leading-edge solution for accessing SNA applications over TCP/IP networks, offers levels of reliability, scalability and control similar to those provided by SNA networks. Enterprise Extender uses standard Internet Protocol (IP) technology and requires no new hardware or software in the IP backbone.

Security
IBM Communications Server offers TN3270E, supporting Secure Sockets Layer (SSL) authentication and encryption across the TCP/IP network. The built-in security of SSL helps to protect your data from eavesdropping, tampering or message forgery over TCP/IP, utilizing SSL-enabled TN3270 clients connected to IBM Communications Server. Streamlined 3270 access with the express logon function of IBM Communications Server, a user running a 3270 client session can log on to a host system without having to enter the user ID and password as the means of authenticating the user. One advantage of using this function is that it reduces the time spent by an administrator maintaining host user IDs and passwords. It can also reduce the number of user IDs and passwords that users have to remember. To take advantage of the express logon function, a TN3270 client, such as IBM WebSphere® Host On-Demand, Version 5.0 or later and IBM Communications Server for OS/390 as found in IBM OS/390 ®, Version 2 Release 10, is required.

Network performance
IBM Communications Server can help improve the availability and performance of your network. Using High-Performance Routing (HPR), it offers the ability to reroute traffic around network failures and congestion. Additionally, it provides highly intelligent session management to help minimize network congestion and maximize throughput.

SNA Services
IBM Communications Server provides all-in-one SNA communications services between workstations and a System/390(R) or an AS/400(R) system, as well as other workstations. Capabilities include a full function SNA gateway, the most advanced peer-to-peer networking system in the industry, support for many types of connectivities, and a rich set of application programming interfaces (APIs). Of particular significance is the support of SNA, which is based on IBM's long experience as the architect and developer of this important networking protocol.

Advanced Peer-to-Peer Networking (APPN)
The IBM Communication Server Advanced Peer-to-Peer Networking(R) (APPN(R)) support includes SNA networking facilities that connect distributed computing applications, peer applications, and client applications to their servers. The IBM Communications Server also includes support for high-performance routing, which improves availability and throughput for network communication. The IBM Communications Server APPN support provides:

• Error recovery
• Connection awareness
• Sophisticated flow control
• Segmentation at the end points of a connection, and frees intermediate nodes to move data

High Performance Routing (HPR) provides significant network efficiencies in most typical communications environments. If an intermediate link or node in a connection route fails, HPR can determine a new connection route and resume transmission without disrupting your users' sessions.

Enterprise-Class Networking
Branch Extender is an Advanced Peer-to-Peer Networking(R) (APPN(R)) border node subset that is designed to interconnect a remote branch office to an APPN wide area network (WAN) backbone. Branch Extender optimizes the peer-to-peer communication environment for administrators who want to connect local area network (LAN)-based branches to one large WAN. The Branch Extender enables customers to interconnect a branch office with LANs, end nodes and low entry networking nodes with dependent and independent logical units (LUs), and physical units (PUs) such as teller machines to one or several WANs. Specifically, Branch Extender:

• Reduces the number of network nodes in large APPN networks
• Enables the addition of branch networks
• Provides for substantial savings in network costs

The Enterprise Extender data link control allows the Communications Server for Linux to provide high-performance routing (HPR) connections on IP networks, using UDP/IP packets. To the HPR network, the Internet protocol (IP) backbone appears to be a logical link. To the IP network, the SNA traffic appears to be a user datagram protocol (UDP) application. These datagrams are routed without changes to the IP backbone. Because there is no protocol transformation and because packaging takes place at the routing layer without the overhead of additional transport layers, this results in efficient use of the intranet infrastructure for IP clients that access SNA-based data (TN3270 clients or Web browsers using IBM Host On-Demand, for example), as well as for SNA clients.

Simplified administration
IBM Communications Server allows you to perform server administration over an intranet or the Internet. From either a remote or local workstation, the administrator can manage IBM Communications Server by telnetting into the desired server.

Power programming
IBM Communications Server provides a sophisticated programming interface, supporting a wide range of application programming interfaces (APIs) for the program developer. These APIs offer convenient ways for the programmer to access IBM Communications Server functions.

Conventional LUA - RUI and SLI ( supports LU 0, 1, 2, 3)
CPI-C and Advanced program-to-program communications (APPC) supporting both dependent and independent LU 6.2
The extensions of Common Programming Interface for Communications (CPI-C) to support Java applications as well as standard C-language programs.
Host Access Class Library (HACL)
Common services (CSV)
Network management services (MS)
Node Operator Facility (NOF)

The APPC Application Suite is also provided, which provides several applets that are useful for testing and problem determination. Applets include APING, ATELL, ANAME, AREXEC, AFTP and ACOPY.