CAD a doddle for distributed system

For architect Chapman Taylor the move to new premises provided an opportunity to cast off an old, anarchic network that had grown...

For architect Chapman Taylor the move to new premises provided an opportunity to cast off an old, anarchic network that had grown organically over a period of years, writes Antony Adshead.

At its new offices the company installed a 3Com expandable resilient networking (XRN)-based infrastructure which has given the company the fully-redundant Gigabit-capacity handling usually associated with far larger, chassis-based systems.

Chapman Taylor needed a network that could handle the large amounts of traffic generated by the architect's practice, working with large CAD graphic files and design information which is being frequently exchanged with customers and contractors.

Architects need to solve these issues quickly and any downtime can lead to costly delays in projects. So far, according to communications and network manager Shan Tilakumara, the £68,000 implementation has not had one instance of downtime in five months, and will have proved its worth in terms of return on investment for that reason alone.

Tilakumara chose the 3Com equipment after following a rigorous selection and testing procedure.

"The network is bandwidth-hungry and we need to solve problems quickly. We looked at Cisco and 3Com equipment and approached reference companies and contacts in the industry. Then we had 3Com 4050s on a testbed and replicated our planned 14 VLan and printer Lan set-up," he said.

The network configuration selected was 3Com's XRN. The essence of this topology is for there to be two Gigabit switches linked together as a one Gigabit device, replicating one another constantly via a so-called "distributed fabric", and which are each linked to the same network nodes each side of the central switching devices.

The practical benefit is that the devices think they are one entity and network management software constantly monitors the state of traffic. Should one device go down the other immediately takes over the workload.

The scheme gives stackable switches some of the advantages of larger chassis switches, such as redundant hot-swappable power supplies.

When it came to going live Tilakumara said the major challenge was getting the network up and running in four days. "The testing and background work helped immeasurably, but it was a tense time because it was a brand new technology and we had to deliver a complete network by 9am on Monday morning," he said.

The system comprises 20 servers supplying 250 desktops via 3Com 4400 edge switches from the two 3Com 4050 XRN switches on a Gigabit core.

3Com's expandable resilient networking architecture   

Chapman Taylor needed to get a new network up from scratch in four days to move into new premises and serve 250 architects using high bandwidth applications 

The network uses 3Com's expandable resilient networking infrastructure which uses two core switches which each think of themselves as one, but can handle all traffic singly should the other go down, acting in a similar manner to much more expensive chassis switches 

Chapman Taylor has so far had no downtime after five months of network use.

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