ACC Extends SNA Internetworking To Its Line Of ACCess Routers; New SNA Express Implementation Allows Connectivity to IBM-Based Solutions to Piggy Back on Savings Associated with Exclusive Bandwidth Optimization Technology.

CUPERTINO, Calif.--(BUSINESS WIRE)--May 9, 1995--Advanced Computer Communications Inc., (ACC) today announced continued enhancement of their integrated SNA network strategy, SNA Express, with the implementation of their new 8.0 software release.

ACC has recognized the growing demand for cost-effective peer-to-peer network solutions that complement existing hierarchical SNA networks. SNA Express delivers to the IBM network operation and its end users a flexible network infrastructure that protects previous investments in IBM equipment and provides access to next generation technology. The key components of ACC's new SNA implementation include: -0-

- Compressed SNA over Frame Relay 

- Express Queuing(TM) Prioritization

- Data Link Switching (DLSw)

- Integrated SDLC/LLC2 Conversion -0-

ACC's SNA Express is a manageable networking capability that minimizes lifetime network operating costs while delivering on the needs of network end users. Extending ACC's Bandwidth Optimization technology to support SNA networks help reduce recurring wide area costs while delivering high performance predictable end user response times. The main components of ACC's Bandwidth Optimization that have been extended into a SNA internetworking environment include Data Compression, and ACC's exclusive Express Queuing(TM) automatic queuing algorithm.

Compressed SNA Over Frame Relay

Many SNA networks are currently being converted from leased lines running SDLC to switched services such as frame relay which typically offer a 30% savings over monthly leased line costs. For corporations running SNA on a separate data network additional savings can be realized by consolidating the corporate Wide Area Network (WAN) into a frame relay scheme. Using ACC's data compression over frame relay, customers derive further benefit by receiving a least four times the performance out of the same existing network.

"End user response times, such as 3270 interactive terminal sessions, are noticeably faster due to ACC's Data Compression over frame relay option," said Gary Krall, ACC's vice president of Marketing. "At the same time Data Compression also realizes further savings by requiring fewer WAN circuits or by giving users the option of even staying with 56/64Kbps access links rather than moving to more costly fractional T1 lines."

SNA Express

Although there are immediate cost savings when converting a SNA network to frame relay, it is also difficult to maintain the same workgroup environment that 3270 users have become familiar with. The number one networking parameter that a 3270 user experiences day-to-day is response time, and when using leased lines dedicated to 3270 terminal traffic response times are fairly easy to control. The challenge that a network administrator faces is guaranteeing short and consistent response times while working in a bursty multiprotocol environment where 10 and 16 Mbps networks are converging onto a 56/64Kbps WAN link. A priority mechanism must be utilized so that terminal traffic can bypass the congested transmit queue.

To solve this dilemma, ACC has extended its exclusive Express Queuing technology to dynamically allocate bandwidth in a SNA environment. Express Queuing delivers predictable response times by automatically prioritizing interactive terminal users over file transfers. Each established session is automatically allocated a portion of the bandwidth, analogous to Time-Division-Multiplexing (TDM) that dynamically allocates an equal slice of available bandwidth to individual sessions. Express Queuing guarantees that file transfers do not receive more than their allocated bandwidth, and if a terminal session does not use all of its allocated bandwidth, it is reapportioned to other sessions. The unique value of this queuing algorithm is that it is automatic and dynamic. Network managers do not have to add configuration commands in order to prioritize sessions -- which is common for other implementations.

Prioritization above Express Queuing is offered in release 8.0 for network managers that need to fine tune response times beyond automatic control. For example, individual PUs can be selected allowing certain stations priority regardless of the type of service they are using. This can be effective for selected workstations that need priority above and beyond the fair queuing algorithm provided by Express Queuing.

ACC's prioritization algorithms were independently measured in the industry's first benchmark test specifically designed to measure SNA performance over Frame Relay. The multivendor tests -- conducted by the Tolly Group -- measured SNA data throughput and response times over a Frame Relay network. The tests also measured the affect on SNA response times of background LAN-to-LAN file transfers over the same link. This document is available on The Tolly Group's World Wide Web server at http://www.tolly.com.

Data Link Switching (DLSw)

With the introduction of DLSw, network managers have a standard alternative to source route bridging in a multi-protocol environment. Data-link switching is a means of transporting SNA and NetBIOS traffic over an IP network. DLSw addresses several problems inherent in the SRB protocol, including: -0-

- SRB hop-count limit (SRB limit is 7): Terminating the local LLC Type 2 sessions before going over the WAN Link resets the SRB limit and allows an addition 7 hops.

- Broadcast traffic (from SRB explorer frames or NetBIOS name queries): Local termination and name caching eliminates broadcast traffic and LLC Type 2 Polling, reserving precious WAN bandwidth for information frames.

- Unnecessary traffic (acknowledgments and keepalives): Further reduction in WAN traffic can be accomplished using the new DLSw filtering capabilities, restricting specified addresses or NetBIOS traffic from going out over the WAN

- DLC time-outs: DLC time-outs, which are more likely over lower speed congested WAN links, are eliminated since the router handles all acknowledgments locally. -0-

"The popularity of Data Link Switching is evidence that it meets an important customer need," said Louise Herndon Wells, director of IBM Internetworking at Internetwork Technology Institute and chair of the Data Link Switching Related Interest Group. "Router vendors such as ACC are rushing to meet this demand for a solution that integrates the customer needs in existing SNA and IP networks.

ACC's DLSw feature is supported on all hardware offerings, including the Amazon, Nile and Danube, as well as all other hardware platforms.

Integrated SDLC/LLC2 Conversion

SNA Express provides support for SDLC to LLC Type 2 conversion which is useful in IBM SNA networks consisting of both SDLC serial links and LANs. Effecting communications between IBM equipment using SDLC and a LAN-attached front-end processor (FEP) is difficult, however, since some IBM SDLC equipment cannot be converted for LAN use. For example, the 3274 controller does not support a LAN interface. The SDLC to LLC Type 2 conversion support in Release 8.0 allow devices using SDLC to appear to the FEP as if they were directly connected to LAN, thus providing a communications path between the LAN-attached FEP and the PU2/PU2.1 devices.

Release 8.0 will be able to support the SDLC/LLC Type 2 conversion between two physical ports on a single router, between a physical port and a "logical" port on a single router, and between physical ports on two different routers.

Price and Availability

ACC's SNA Express is included in software release 8.0 and will be available in June and will be included with all new ACC bridge/router shipments. Customers who currently have a maintenance contract with ACC will receive Release 8.0 software free of charge. Customers who do not have a maintenance contract will be charged a nominal upgrade fee.

About ACC

ACC is a leading manufacturer of wide-area internetworking products that provide cost-effective interconnection and management of geographically distributed computer networks. ACC leads the industry in the development of Bandwidth Optimization technologies to maximize the utilization of leased line and switched services. ACC's products are sold world-wide through 80 leading international VARs and OEMs serving corporate and business customers, educational institutions, health care, retail establishments, governments, and PTTs.

Advanced Computer Communications is headquartered at 10261 Bubb Road, Cupertino, CA 95014; telephone: [phone]; FAX: [phone]. INTERNET [e-mail]. World Wide Web: http://www.acc.com.

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Note to Editors: Danube, Nile and Amazon are trademarks of Advanced Computer Communications. All other trademarks are the property of their respective owners.

CONTACT: Advanced Computer Communications

Rich Black or Trish Voskovitch, 408/366-9600