British Telecommunications Plc is reviewing its ISDN prices following the complaints from the Office of Telecommunications that its tariffs are discriminatory. Telecommunications director general Don Cruickshank has asked Telecom to review its tariffs, which he said were likely to have anti-competitive effects on customers and competitors who provide a similar service. The ISDN network is used by many small businesses, schools and some individuals for Internet access. Cruickshank said he has given Telecom a few days to meet his demands.