Twisted-I air connections for workstahons

A cluster communications system has been launched that links work- stations together over standard telephone 'twisted pair' wire.

The advanced TeleCluster design, from Unisys, allows data to share the same twisted pair wire used for voice by analogue telephone (Type 500 and 2500). Any Unisys BTOS workstation model can be connected, along with PCs using ClusterShare, a recently announced software/interface card enabling PCs to coexist on BTOS clusters.

TeleCluster is designed to meet networking needs for environments where people want to use standard in-place wiring rather than installing RS-422 cable. In addition, TeleCluster can be used at installations where star

topology is more appropriate than daisy-chain cluster cabling, and where increased master-to-cluster workstation distances are specified.

Cabling, workstation mobility and installation costs are key issues in all large workstation purchases. The star topology used by TeleCluster enables it to be used for prewiring a building or installation.

Basically, TeleCluster consists of two components, an adapter and a hub. The adapter plugs into an AC power outlet and into a standard RJ- 11 telephone wall connector, linking the telephone instruments and a workstation to existing wiring .Up to three workstations can be daisy- chain connected to each workstation on an adapter.

The hub ties the TeleCluster network together in a star topology and is generally located near a PBX. The hub separates signals received from the adapter, sending voice to a patch panel or PBX and the data to other adapters. Individual runs of twisted pair wiring from a hub to an adapter can be up to 1200 feet long. A single TeleCluster hub can support either 12 or 24 adapters. Each adapter can support multiple workstations.

The telephone portion of TeleCluster uses passive circuitn t that allows the phone system to remain operational even when the TeleCluster components are switched off or fail. TeleCluster communications operates at 307 kbit/s or 1.8 Mbit/s and is completely transparent to the BTOS system software.

Unisys is about to undertake qualifi- cation for usage of TeleCluster with the UK telephone system. (Unisys Ltd., Stonebridge Park, London NW10 8LS, UK. Tel: 01-965 0511 Telex: 8951141) []

Software support for X.25 on VAX VMS systems

Users of VAX VMS-based systems will be able to run Fusion Network Software (FNS) supporting the X.25 protocol.

This gateway software, from the Network Research Corporation, will enable multiple remote networks to be connected via the British Telecom's PSS service or private packet switching network, providing a seamless network to the user.

In addition to level 3 (transport) services the software also supports all the application level services offered to TCP/IP Ethernet users, including Telnet, ftp, rlogin, rcp, NFS and Netbios. Third party services will be routed across the PSS network.

Another feature is the full implementation of ICMP which provides a transparent source quench for gateway congestion, Security Precedence which enables operators to assign precedence when multiple users access the network, and Subnetting to Classes A, B, or C

networks. This option complements the point-to-point support on DMV- 11 and DMR-11 controllers already available.

Fusion X.25 software is initially available using ACC 6250 (Unibus)

Ethernet transceiver

An Ethemet transceiver has been launched which provides the user with a variety of functions: it will both transmit and receive data on the network, will detect data packets that are overlength and will prevent packets colliding.

The transceiver, from MBS Communications, is called the NL1000 and is designed for connections to the 10 Mbit/s Ethernet network. It is connected to network equipment using a drop cable, and to a local area network

and 5259 (Qbus) controllers. Future releases will support additional vendors controllers. Unix, Xenix and MS-DOS users on LANs are able to tie into the wide area network through connection to the VMS system.

Network Research Corporation products are marketed in the UK by Unipalm. (Unipalm, Unit 9, Viking Way, Bear Hill, Cambridge, Cambs CB3 8EL, UK. Tel: (0954) 82947, Telex: 817936 CAMTEL G) []

(I_AN) usinga coaxial cable. It can also be connected to 'thin-net' coaxial cable systems. It provides a selectable SQE or 'heartbeat' function and low-level system diagnostics (power, packet reception/ transmission and collision) that are indicated by LEDs. It fully conforms with networking standards, including the IEEE 802.3 Ethernet standard. (MBS Communications Ltd., 119/120 High Street, Eton, Windsor SL4 6AN, UK. Tek (06286) 68500, Telex: 848912) [ ]

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