Interlink provides first fault tolerant TCP IP for MVS mainframes; Mission-critical support for TCP IP-based client server computing environments.

FREMONT, Calif.--(BUSINESS WIRE)--Jan. 20, 1995--Interlink Computer Sciences Inc., which is dedicated to bringing mainframe- level services to client/server computing environments, has introduced the first fault-tolerant capability for TCP/IP-based networks linked to IBM mainframes.

The new unique add-on feature for Interlink's TCPaccess version 3.1 -- TCPaccess-Fault Tolerant -- provides "graceful" recovery by automatically rerouting sessions and assuring session persistence in the face of hardware failures, line failures or routing changes. This gives IS departments the ability to implement 24-hour, 7-day-a-week support for mission-critical applications.

Interlink has also announced other enhancements to TCPaccess 3.1 including increased manageability and compatibility.

"Mainframe customers are accustomed to high service standards so it comes as no surprise that they want those same standards for extending mission-critical applications to the heterogeneous networked computers and printers that now populate their organizations," said Interlink's president Chuck Jepson.

"At Interlink, we are taking the lead in providing the traditional data center service standards that IS managers want when using TCP/IP to extend mainframe resources to the networks. Fault tolerance is just the first in a series of capabilities from Interlink that will bring data center quality standards to the client/server market."

TCPaccess-Fault Tolerant-How It Works

TCPaccess 3.1 is offered with an additional module, TCPaccess-Fault Tolerant, the only available fault tolerant version of TCP/IP for MVS. Used in conjunction with redundant network interface and routing hardware, TCPaccess-Fault Tolerant software provides the facilities to eliminate the weak links in TCP/IP MVS environments- LAN controllers and routers.

TCPaccess-Fault Tolerant automatically reroutes end users to a redundant LAN controller or router, allowing user sessions to persist during a hardware failure or router outage or change.

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TCPaccess-Fault Tolerant uses:

-- Multiplexing utilities and Address Resolution Protocol (ARP) enhancements to handle controller failures;

-- The Gateway Daemon (GateD) with Open Shortest Path First (OSPF) and Routing Information Protocol (RIP) dynamic routing protocols to support router failures and changes.

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"Without fault tolerance, when a LAN controller or router fails, sessions go down and are lost, people get angry, phones rings, pagers go off, operators get involved -- in short, companies loose productivity. With our fault tolerant solution, sessions don't go down," said Chris Markle, chief technology officer for Interlink.

"This feature is very popular with our customers who have client/server environments characterized by numerous user connections, heavy session traffic and requirements for immediate response."

Uses multiplexing and ARP to respond automatically to controller failures

TCPaccess-Fault Tolerant provides complete, "bullet-proof" protection against controller failures for both inbound and outbound sessions between the mainframe host and network hosts.

Redundant controllers are multiplexed, allowing multiple interfaces to a mainframe host with a single IP address. The TCPaccess-Fault Tolerant multiplexing facility monitors controllers for failures, uses the Address Resolution Protocol (ARP) to direct hosts on the network to use a new interface for sessions with the mainframe, and restarts failed controllers when they recover.

Uses GateD to respond quickly to routing outages

Using the Gateway Daemon (GateD) on the mainframe, TCPaccess-Fault Tolerant implements open systems interior and exterior routing protocols from within the mainframe to detect changes in the routing environment and dynamically act upon the changes fast enough to keep sessions from being interrupted or delayed.

TCPaccess-Fault Tolerant implements OSPF and RIP, allowing the mainframe to look like a router and participate in the flow of routing information to keep TCPaccess updated as to the best routes to remote destinations. OSPF, in particular, allows the mainframe to detect and update changes in the network environment in 30 seconds or less, keeping active user sessions going and allowing new sessions to start immediately.

SNS/TCPaccess 3.1 Enhancements

TCPaccess is Interlink's core product for connecting TCP/IP networks to MVS processors and SNA networks. SNS/TCPaccess resides on the mainframe and provides the fundamental TCP/IP communications services between the MVS system and networked computers and printers, including file transfer, terminal access, Simple Network Management Protocol (SNMP) services, mail transport, and network-to-mainframe printing.

The company's last release was built for optimal MVS efficiency and power. TCPaccess 2.1 provided substantial enhancements in performance and throughput over earlier versions -- supporting thousands of simultaneous 3270 Telnet sessions from thousands of remote hosts. FTP file transfer processing is faster while using CPU resources efficiently.

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TCPaccess 3.1 new features include:

Increased manageability

-- Enhanced national language support -- Use of common translation tables throughout the product family provides rapid and accurate configuration of the tables used to translate national language character sets from mainframe EBCDIC code to the ASCII code commonly used by remote systems.

-- Server Telnet USS MSG support -- Direct access to VTAM USS table definitions through TCP/IP increases transparency to end users and eliminates the need for training when SNA 3270 users are transitioned to tn3270.

-- Improved diagnostic facilities and new test tools -- Improvements to the diagnostic facilities and the addition of new test tools allow for faster and more accurate isolation and resolution of software, routing, and connectivity problems.

Improvements in compatibility

--Server FTP enhancements -- Increased server FTP functionality makes using mainframe resources and data more convenient for end users in the TCP/IP network. Mainframe data management facilities like SMS (Systems Managed Storage) and PDSE (Partitioned Data Set Extended) can now be fully exploited.

-- Enhanced SAS/C Socket Library Compatibility -- Support of SAS/CSL eases the porting of Unix applications to MVS, particularly those using the X-Window API.

-- "Raw" API Interface for Assembler and Sockets API's -- Direct access to the IP layer within TCP/IP gives programmers significantly more flexibility to create custom "IP-level" applications.

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Interlink Computer Sciences Inc.

Founded in 1982, Interlink is a pioneer in developing interoperability applications that connect mainframes with disparate systems within networks. Interlink develops a full range of products for transparently integrating data and computing resources throughout enterprise information systems.

By removing the traditional barriers between mainframe computers and local and wide-area networks, Interlink products enable organizations to fully utilize their information systems investment and extend user-access to business information.

As one of the top two companies providing TCP/IP-based client/server connectivity for IBM mainframes, Interlink products enable users of IBM SNA environments to exchange files, send messages and share hardware resources with computers on TCP/IP, DECnet and NFS networks. Similarly, users on these networks can retrieve information and access resources on IBM mainframes equipped with Interlink software.

Headquartered in Fremont, Interlink is an international company with sales and support offices in all major markets in North America and Europe. In South America, Asia and Australia the company markets its products through distributors.

Price and Availability

TCPaccess 3.1 and TCPaccess-Fault Tolerant will be available in March 1994. Pricing is CPU-based and ranges from $19,000 to $62,000 for TCPaccess 3.1; $9,000 to $20,000 for TCPaccess-Fault Tolerant.

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For sales & marketing information contact:

Interlink Computer Sciences

47370 Fremont Boulevard

Fremont, CA 94538

800/422-3711

CONTACT: Interlink Computer Sciences

Linda Nixon, 510/249-6209

Niehaus Ryan Haller Public Relations

Bill Ryan, 415/615-7906