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Standard Fault Investigation service

Our Standard Fault Investigation service (or SFI for short) is a service that we (Andrews & Arnold Ltd) offer to British Telecommunications plc (BT) to assist BT in the diagnosis of faults on broadband lines.

A service to BT Wholesale

BT Wholesale provide us with IPStream and WBC End User Access broadband services. These have a service delivery point that is the master socket in the end users premises.

BT Wholesale have a range of tests available to diagnose any issues with these services, but they do not appear to have any means to carry out tests actually at the service delivery point.

This can lead to problems where a fault exists that is only apparent at the service delivery point and tests at the exchange do not identify the cause.

This puts BT Wholesale is a difficult position as they are unable to credibly refute any claim we make that there is a fault in the service.

To help resolve this, our SFI service provides a means to diagnose the fault at the service delivery point.

SFI service

The Standard Fault Investigation (SFI) service we offer consists of the following steps:-

  • Preparation of a BT branded, BT supplied, router at our offices
  • Testing of the router on a working ADSL line at our offices
  • Shipping the router to the end user concerned
  • Ensuring the end user connects to the test point on the master socket at their premises eliminating all of their wiring and equipment totally
  • If logging in, performing continuous LCP monitoring for many hours
  • Performing constant ATM echo tests and gathering statistics from the router for several hours
  • Arranging return of the router to our premises
  • Re-testing the router on a working ADSL line at our premises
  • Analysis of the findings and reporting back to BT

Service availability

There are a limited number of test routers available, and limited availability of engineering time to prepare, test and ship the routers. As such we will have to book an SFI for BT. However, we aim to prepare, test and ship same day if at all possible.

End user appointment service

Obviously requesting the SFI service is not a mandatory part of the fault diagnosis process and BT may wish to arrange an End User Appointment to gain access to the service delivery point in order to carry our their own tests. This can be arranged through us as a free service. Should the BT engineer fail to arrive within the appointed time-frame then BT will be liable to pay us an abortive visit charge of £85.00+VAT which we pass on to the end user to compensate them for the inconvenience.


To order the SFI service BT simply need to ask us to book an SFI. We will book the SFI as soon as possible and advise BT of the outcome (usually within 1 to 2 working day).


In the event that the SFI service demonstrates that the fault lies with customer equipment (i.e. the test router works correctly) we make no charge for this service to BT. If we are unable to confirm that the fault lies with the end user equipment then a charge of £144.00+VAT is payable by BT for the service. If BT are confident that the fault lies with customer equipment then BT can safely book the SFI service with no risk of charges.


Obviously if BT choose to make use of this service as part of the diagnosis and repair process then BT have to be aware that the time taken to carry out this service may well be longer than the 40 hour repair time BT offer us. Should the outcome confirm that there was no end user equipment fault then the total time will be considered when claiming SLG payments from BT.

Not taking this service

Obviously BT do not have to take this service, it is an optional service. If we assert there is a fault at the service delivery point and BT have not performed any tests at the service delivery point, then the onus is on BT to rectify the fault. As such BT have to do something and this service simply makes more options available.