Today's network nightmare at BT has been described as the "the biggest technical problem BT has ever faced", according to one anonymous source within the telco. Two gateways in Cambridge and Leeds crashed simultaneously earlier this morning severely impacting the performance of BT's network. BT's third gateway in Croydon is currently working at full tilt to cope with demand. Today's network problem has affected the availability of 0800, 0845 and 0345 numbers. A spokesman for BT said he couldn't be absolutely sure it was "the biggest technical problem" ever but conceded that it was a "pretty major network problem". He also said it was a "major incident". It is still not known what caused the outage. BT has not ruled out foul play, although this is thought to be unlikely. ® Related stories: BT network falls over