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  1. Technology
November 21, 1988


By CBR Staff Writer

IBM seeks to have 16Mbps option added to IEEE 802.5 standard for Token Ring nets

Claiming that its local area network users will now be able to communicate with equal ease across a campus or a continent, IBM has produced an expanded version of last Monday’s Token Ring announcements (CI No 1,058). Of primary significance is the quadrupling of the rate at which information can be sent and received across an IBM Token Ring network to 16Mbits-per-second from 4Mbits. The 16Mbps Token Ring Network also provides a new Early Token Release enhancement, enabling multiple data units or frames to co-reside simultaneously on the ring, which should speed up performance on heavily loaded networks. According to IBM, instead of having to wait for its data frame to return, a workstation on an early release network can now transmit a token as soon as a frame has been dispatched. Chief benefits include more efficient use of the network: the company claims ring efficiency now exceeds 95% for all frames over 128Mb in size, regardless of ring length. Both Early Release and the 16Mbps net have been submitted by IBM to the International Standards Organisation and members of the IEEE 802.5 committee for, it hopes, ratification and embodiment in an extension to the standard 802.5 Token Ring specification.

16/4 Adaptor boards for MS-DOS micros and for Micro Channel PS/2s Key new hardware products are the new 16/4 Adaptor and 16/4 Adaptor/A boards for attaching MS-DOS micros and PS/2s with Micro Channel Architecture. The boards, which can be switched to operate at either 16Mbps or 4Mbps as required, now offer 64Kb of memory – up from 8Kb or 16Kb – enabling the use of larger data frames. By breaking the previous 2,000 bytes limit, IBM claims 16Mbps and 4Mbps networks can now support a maximum of 18,000 and 4,500 bytes respectively, increasing data transmission efficiencies on some specialised applications by as much as 300%. The boards also accommodate the kind of high-volume, direct memory-to-memory transmissions required for image applications. Performance is also boosted by the boards’ exploitation of a new mixed analogue-digital chip, developed at the company’s sites in Research Triangle Park, North Carolina and Essex Junction, Vermont (which aren’t exactly close together – look at the map: that’s how good the new network is!) and fabricated in IBM’s cooler-running CMOS technology. For the new 40,000-circuit version, IBM engineers integrated six separate chip functions, enhancing reliability, and enabling the new adaptors to be packaged in a half-size board. IBM has set up joint board testing agreements with Apollo Computer, Sun Microsystems and Banyan Systems, and says it has already received operation verifications spanning a range of hardware and software environments from Novell Inc. Both boards will be available in the UK in December, for a list price of UKP675. Other hardware announcements include a Type 3A Dual Speed Adaptor and Supporting Micro-code for the 3174 terminal controller for 3270-type displays, providing alternate host and gateway attachments for networks operating at either 16Mbps or 4Mbps. IBM claims that, with the new adaptor, substantially improved gateway throughput – up to 140 DSPU Down-Stream Physical Units as PU 2.0 nodes – can be suppoted at either speed, with the use of the larger frame sizes. UK list price for the controller, which should be out in October 1989, is UKP3,643.

Support for 3745, 9370, Series/1… In terms of linking to other IBM architectures, users of the new 16Mbps network will gain access to SNA through a 3745 Token Ring Adaptor Type 2, available in June 1989 for UKP17,430. Similarly, a Token-Ring 16/4Mbps Adaptor for the 9370, planned for the second quarter of next year, will enable mid-range attachments, with the 9370 acting as server, application machine or a gateway to another computing system. In August 1989, IBM also plans to offer a UKP3,281 Series/1 Token-Ring attachment board, enabling attachment of all models of the 4956 processor to rings operating at either speed.

…and a commit

ment for the AS/400 And in the promises, promises department, there is a Statement of Direction that IBM intends to provide support for attachment of the AS/400, using Version 2.0 of the Token-Ring Network Bridge Program, due for release in February 1989 and priced at UKP1,072. Version 2.0 will also extend the capabilities of 1.1, by enabling users to interconnect Token Ring networks to form one logical ring. By bridging rings operating at either the same speed or different speeds, explains IBM, it will allow the new 16Mbps ring to work with existing 4Mbps rings. Version 2.0 will be available in February 1989 for UKP1,072, with an upgraded Version 2.1, priced at UKP527, planned for July. Version 2.1 will provide remote bridging facilities at selectable speeds on leased line 9.6Kbps to 1.344Mbps teleprocessing transmission facilities.

8220 Optical fibre converter Final major announcement is the 8220 Optical Fibre Converter, an electrical-to-optical and optical-to-electrical converter, which forms a subsystem by connecting two 8220s with a 6,000 foot fibre link. When the converter is combined with the IBM Cabling System, a Token Ring can provide service for a big multi-site building. Other significant advantages cited by the company include active participation in diagnostics and network management; in the event of a fibre sub-system failure, the 8220 pair wraps the main ring to the backup ring, maintaining operation and eliminating the need for manual intervention. In add-ition, if the 8220 is defined as a critical resource, the IBM LAN Manager can monitor the 8220 for errors, and begin the problem determination process. The fibre sub-system should be available for UKP2,388, subject to it getting the nod from the British Approvals Board for Telecommunications. In a final note, IBM adds that its PC Network Bridge Program, an enhanced version of its PC Token-Ring Network PC Adaptor II, OS/2 Extended Edition Version 1.1, the OS/2 LAN Server Program, and the LAN Network Management Programs anounced in September, now support 16Mbps Token Ring Networks.

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