Customers desert IBM for Interlink

IBM is losing customers because its mainframe TCP/IP implementation is too memory hungry, despite the release of a tuned controller version.

Some mainframe users evaluating IBM against its rival, Interlink TCPaccess, have found Interlink to be better. IBM admits that its TCP/IP performance is not as good as it should be.

The issue arises when mainframe sites want to migrate from IBM's legacy SNA protocol to TCP/IP, which is more open.

Cossy Cosmas, senior technical services analyst with BOC Gases, said: 'When we decided to standardise on TCP/IP as a corporate standard we were pretty green, so we just purchased the IBM 3172 network controller. But as our requirements grew, we realised it left something to be desired.'

BOC Gases is in the process of migrating from the mainframe to IBM RS/6000 and Oracle applications.

Abbey Life Assurance has also carried out an in-depth comparison. An internal document said: 'The file transfer performance of the Interlink product is significantly superior to that of IBM's product. Technical support received from Interlink was superior to that provided by IBM.'

Abbey is going live with a big application based on TCP/

IP file transfer: a sales support system for laptops and Unix which relies on data transfer with an IBM mainframe.

Roy Hewitt, project manager responsible for TCP/IP on the mainframe at National Power, said the utility was midway through a migration from the DECnet protocol to TCP/IP. The IBM implementation, he said, used twice as much processing power as the Interlink version.

Mark Cathcart, open systems consultant at IBM UK, admitted: 'If Interlink can do better than us, and customers want it, then we're all for that.'