US disaster tests networks around the world...Telephone traffic surged following yesterday's horrific incidents in the US with all major telcos reporting much higher volume than normal. BT said it asked all staff working at its Dundee call centre - where international directory enquiries are based - to report to work to help deal with the "ten-fold surge" in transatlantic calls. BT reported its network was not affected in the UK by the high traffic levels, although many worried callers were unable to be connected to numbers in New York and Washington DC because of calls flooding into the areas from around the world. US long-distance carrier AT&T said its traffic was also higher than normal and advised callers not to ring either city to help keep phone lines open for emergency services. The US telco said its calls doubled after the attacks with an average of four million calls every five minutes. Mobile operators Orange and Vodafone said they had difficulty connecting callers to the US Eastern seaboard, with Vodafone reporting its traffic was up 30 per cent compared to a normal day. Despite the heavy traffic and failed connections for many hours, none of the networks are known to have collapsed under the strain.