Telephone sytem faultingI can fault most types of home telephone installation and if I haven't come across yours before I am sure that I have a contact who has.   As for business phone systems I have lots of experience of Avaya or Lucent Definity and would be able to help with most problems.   As for other systems I don't mind discussing them with you and I would certainly take a look for no charge and let you know whether I can do anything to help you. A few successes I have had lately:
In another instance BT had been along to a fault where the customer had complained about noisy calls and slow broadband.   Their engineer had rewired the extensions internally and had not solved the problem. I spotted that one leg of the line outside the property was joined with a dry joint exposed to the rain.
I try to keep an up to date rogues gallery of faults with an explanation of each of them on my facebook page at TELEPHONE ENGINEER IN YORK, ALL MOD COMMS.