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BT sues supplier for £72m over exchange gear that allegedly caused wave of ADSL outages

Tii Technologies claims hamfisted BT bods caused problems, not their kit

BT is suing a supplier for £72m after it delivered nearly 100,000 defective landline connection blocks that caused ADSL broadband outages, London's High Court has heard.

Legal filings reveal that Tii Technologies is said to have supplied 95,000 faulty jack test (JT) blocks to BT over a period spanning 2006-2016. The one-time state monopoly claims these faulty blocks led to a spate of ADSL outages in the mid-2010s that mainly affected Sky Broadband's customers – and cost BT more than £40m in engineer callouts to trace the problem's cause.

"In April 2016 (not for the first time), it was reported that the [JT] blocks were causing broadband faults and a complaint to that effect was made by Sky UK Limited, one of the Claimant's largest customers of ADSL broadband services," said BT in filings obtained by The Register.

The £72m lawsuit is a breach of contract dispute. BT says Tii was obliged to deliver JT blocks that were fit for their intended design life of 40 years and should have paid to modify all of them when the cause of the fault became clear.

When it asked Tii to update its 30-year-old JT block design to make it compatible with modern IDC wire terminations, BT claims Tii's designers used bare steel contacts which rusted. The corrosion caused electrical resistance on the connected phone line to rise to the point where ADSL equipment would drop out – meaning the customer's internet connection went down.

JT blocks, BT's court filings said, form a critical part of traditional copper phone lines running between consumers' homes to their nearest telephone exchange. Installed in exchanges' main distribution frames, the blocks consist of two metal contacts, one fixed and one sprung, pressing against the fixed contact. If an engineer needed to test the line for a fault he could wedge the sprung contact open with a test adapter and connect a test probe in its place.

The spate of reported faults caused by the blocks were so bad that Ofcom had to be told about it in mid-2017, BT claimed. Individually modifying each and every one of Tii's 95,256 JT blocks installed on the BT network by "double-jumpering" them is said to have cost £10m.

Tii said in its defence that it had delivered 195,000 metal shims to cure the problems with the blocks, only for BT to ignore them and charge ahead with its own double-jumpering fix, adding: "By reason of the double-jumpering works undertaken unilaterally by the Claimant [BT], the Claimant prevented the Defendant from undertaking any further meaningful investigation."

Your fault, not ours

Tii also told the court that the spate of faults linked to the blocks was caused by inept BT engineers botching installation of the blocks, saying: "On 29 July 2015, Mr. Clive Owens of the Claimant (the BT Specification Authority for the Contract) wrote an email stating that 'I have attended various site visits with the block supplier and have always found that it is an installer problem (usually using the wrong tool) never a block problem'."

The company also denied the steel contacts in the JT blocks were at fault, telling the court: "A break in a contact as described would cause a continuous fault, being a physical or electrical break in connection. Neither would (without external factors for which the Defendant is not responsible) cause intermittent (i.e. irregular or non-continuous) faults."

The £72m sum BT is claiming from TII Technologies, formerly known as Porta Systems, includes £43.7m for "the estimated cost… of engineer callouts" to diagnose apparent line faults on BT's network which the latter says were caused by the defective JT blocks.

£19m of the £72m claimed by BT was paid out by the company to other telcos whose customers complained of ADSL outages. The case, before the Technology and Construction Court branch of the High Court, continues. ®

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