Corporates running private telephone networks are being urged to solve a double bug in telecomms equipment with immediate systems upgrades.
Tony King, telecomms manager at UK utility Thames Water, warned companies to tackle national telephone codes changes at the same time as they upgrade equipment to solve the millennium bug.
If corporates do not make the upgrade they will be unable to make outbound telephone calls because their internal phone network will not be in sync with the telco's national network.
Thames Water, which runs its own large internal network, said few companies had taken the risk seriously. "Nobody is talking about it and I don't think people are especially aware," said King.
Telcos launched a publicity campaign last week to alert the public about changes in telephone dialling codes, planned next June.
Telcos are upgrading their exchanges to handle the new telephone codes, but large corporates who run their own large internal telephone networks must also upgrade hardware, according to King.
Organisations will save time and money and will not have to upgrade phone network equipment twice, said King.
"When doing Year 2000 upgrades, you must make sure the supplier puts in changes for the number change, because you don't want to be paying twice," he added.
King was warned by one supplier that next year's changes would take 10 times longer than previous number changes.
Michael Dixon, chairman of the Telecommunications Managers Association numbering group, which represents users consulting telcos over the changes, said: "If telecoms managers don't have it right already there will be problems. Lots of exchanges don't recognise new numbers so they can't ring them."
Codes for London, Portsmouth, Southampton, Coventry and Northern Ireland will be altered to three-digit codes starting with 02, after next year's changes.
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