Racal Electronics Plc’s Racal Datacom Ltd has launched a small clutch of innovative products, including a high speed proprietary network designed to carry both isochronous (speech or video) and data. The fibre-based network, dubbed Premnet, is the work of Racal Datacom’s Anaheim, California facility, nee Racal Quanta, and it originally started shipping in the US in October 1990 since when it has built an installed base of around 300 nodes. With FDDI 2 more or less dead in the water and practical development of the 802.6 Metropolitan Area Network standard becalmed, Racal is touting its 100Mbps system at users that cannot wait for Asynchronous Transfer Mode networks to carry voice and data. Despite the network’s ability, the company has only just got around to producing a telephony interface board, which is just finishing in-house testing and should ship in the UK later this year. Until now, most interest in the isochronous capabilities have come from users needing to network time-dependent IBM Corp 3270 traffic according to Eric Schade, the company’s US product marketing specialist. Premnet is supposedly transparent to all protocols according to the company, which says it operates at OSI layer 1 only. With an eye to the future and standards, the company says that it plans to migrate the system towards full SONET Sychornous Optical NETwork compliance – the system has the potential to be speeded up to 600Mbps. Prices for an eight-slot node start at around UKP10,000, configured with an Ethernet and a Token Ring board. The 3270, T1/E1 asyncchronous and voice boards vary in price. Racal Datacom has also launched a useful-looking adaptive bandwidth manager that can combine leased-line, Frame Relay and ISDN circuit switched capacity. The product joins the slowly growing band of boxes on the market that are claimed to be able to call up and drop ISDN circuits on the fly to match demand. Speech traffic is usually kept on the permanant circuits while excess data is shifted onto the ISDN lines. The ISX 5540 starts from around UKP16,000, a more typical configuration costs UKP25,000. It has a smaller brother, the ISX 5010. Also launched was the DAP 4500 leased line adaptor with in-built ISDN back-up, and a DAP4100 terminal adaptor.
