NETWORK SYSTEMS ANNOUNCES ESCON-TO-ESCON CONNECTIVITY OVER ANY DISTANCE AND MEDIA.

MINNEAPOLIS--(BUSINESS WIRE)--May 22, 1995-- Network Systems Corp. (NSC) today introduced a new Enterprise Connection (ESCON) Remote Device Interface (RDI) that extends native ESCON channels from mainframes to remote ESCON devices regardless of distance or the type of media connecting them.

The new ESCON RDI complements NSC's host-based ESCON solution introduced a year ago. Together, NSC's remote and host-based ESCON solutions overcome the limitations of ESCON -- and resolve the dilemma of what to do when ESCON won't reach. Both NSC's host and remote device interfaces operate on the company's DXE channel extension platform.

"Since the introduction of ESCON, the Gartner Group has received calls from customers looking for a way to extend it," said Charlie Burns of the Gartner Group. "Now, with NSC's technology, not only can you extend ESCON, but DASD as well. This is an exciting technology, one that represents a true paradigm shift for the better. The Gartner Group will produce a research note soon describing the technology and how to use it," he said.

Full, flexible ESCON connectivity is becoming increasingly critical as data center consolidation and distributed computing place an ever higher premium on reliable, high-performance connectivity. Native ESCON provides excellent connectivity -- but with two critical limitations:

o Depending on the device, ESCON's maximum extension is only 60 kilometers or less -- hardly adequate to accommodate the growing need to connect devices at more distant locations for storage, back-up or disaster recovery.

o ESCON connectivity requires fiber optic cable. Issues of right-of-way and placement of redrive directors make ESCON, as designed today, impossible to use in many situations.

"As we watch the roll out of the Parallel Sysplex technology from IBM, we feel that the connectivity of ESCON will be increasingly important in our multi-data center environment," said Dan Torunian, vice president, Wells Fargo Bank, where ESCON has been in production since 1993. "Network Systems provides for high-performance extension of our ESCON topology. The remote device will allow us to take advantage of unlimited distance and media-independent ESCON connectivity and positions us for connectivity to remote Parallel Sysplex in the future."

NSC's ESCON RDI offers significant advantages over traditional bus-and-tag remote interfaces. Whereas bus-and-tag permits only static connections and, therefore, limits connectivity options, the NSC solution, employing dynamic switching, permits ESCON connectivity to numerous control units. Additional flexibility is gained through the ability of NSC's ESCON RDI to mate non-ESCON-capable control units to an ESCON channel while, at the same time, connecting an ESCON control unit through the same or a different channel.

The benefit of NSC's dynamic-switching solution: Greater flexibility for balancing workloads among devices and sharing resources. Such flexibility is vitally important to today's data center managers -- and is vital to successful disaster recovery.

Plus, with NSC's ESCON solution, system administrators gain the ability to configure ESCON networks at the system-level. This represents a significant improvement over bus-and-tag's manual control.

NSC's ESCON-to-ESCON extension solution is based on host-resident software. Its design -- and its location -- create benefits not available through other ESCON connectivity techniques:

o Unmatched reliability. A non-spoofing device, the NSC ESCON host interface provides ending status to the channel only after it has received it from the remote device. Emulation, on the other hand, provides the host with an OK ending status before the remote or target device begins. NSC's host driver guarantees data delivery and integrity, providing full protection from data corruption. Device recovery routines are managed by MVS as business as usual. And unlike emulation, the host driver is impervious to changes in access methods or control unit microcode changes. This ensures a high level of resiliency to mission-critical configurations.

o Improved throughput and response times, even over great distances. Because the entire channel program and associated data are captured in the host, only a small number of network program messages must be sent over the channel and network to remote equipment. Propagation delay and equipment latency are minimized.

o Optimization of computing resources. The host software driver sends the entire channel program in one transmission at real channel speed, resulting in lower channel utilization. The resulting efficiency alows more devices to be served. System administrators are able to optimize computing resources and save money.

"Contrary to popular belief and competitive positioning, host-driver software does not consume vast amounts of the CPU since CPU resources are required only to manage those devices that are being networked," said Randy Chalfant, NSC marketing manager. "IBM Tucson benchmarked a 3495 tape application at 1.18 percent CPU utilization for block sizes of 32 KB," he said.

"With the host driver's transmission efficiencies and resulting reduction in channel utilization, shared I/O CPU cycles are returned to be used by other applications thus off-setting the number of cycles used. The use of CPU cycles for the host software driver is virtually free," Chalfant added.

In addition, NSC's ESCON host driver provides remote, unlimited distance support for DASD -- a capability no other channel extension technique can offer. DASD support is certified by IBM's ADSTAR Distributed Storage Manager (ASDM).

NSC's ESCON solution, which also fully supports ESCON Multiple Image Facility, is priced at $20,000 per interface. Orders are being taken now for third quarter 1995 delivery.

Minneapolis-based NSC, a wholly owned subsidiary of Storage Technology Corp. (NYSE:STK), provides comprehensive solutions for implementing high performance enterprise networks.

For more information, contact Network Systems at [phone] or via the Internet at www.network.com.

CONTACT: Paul J.J. Payack

Network Systems Corp.

612/424-1555

[e-mail]