Press 4 for Frustration; Press 5 to Pass Blame

Cell phone users at the world's largest technology fair got busy signals followed by silence.

HANOVER, Germany - Mobile phone users at the world's largest information technology fair were put on hold today when a key communications network crashed amid a cellular bottleneck of thousands of journalists, business executives, and convention workers.

Of course, at an event such as CeBIT, where telecom talk was to be in the air all day, those in charge of cellular services scrambled for answers and the high ground.

"These are complicated networks and these things happen," said Peter Mihatsch of the German industry group Mannesmann, whose Mobilfunk network frustrated cellular users earlier in the day with a constant "busy network" response. "It's being worked on feverishly."

Mannesmann Mobilfunk said it was not to blame for the mishap, pointing the finger instead at Deutsche Telekom, Germany's dominant carrier.

"A leased line from Telekom went out of service," a Mobilfunk spokesman said. "The major problems have been repaired and service should be up to full capacity before long."

A spokesman for Deutsche Telekom, which on Tuesday announced plans for a broad launch of Internet telephony services, said a fibre optic cable to which Mannesmann had 76 lines attached broke for no apparent reason.