Are you sure that you have RJ45s? I'm thinking that if you do, that could be your problem. You'd only have a transmit pair. These connections should be via RJ48 wiring patterns.

Next, the telco's 'smart card' has to be configured with the appropriate line build out (LBO) settings. The default is 133 feet maximum, which is where the installers typically leave them. You'll need to inform them of any distances that reach farther so that they can set the card accordingly.

The CAT6 wiring is a complete waste of time and money. With the 25 pair cable in the equation, CAT6 gains you absolutely nothing: The proverbial weakest link. These circuits work ideally on individually shielded transmit/receive pairs, but in the real world, they are fairly tolerant to many site conditions.

I wouldn't waste my time by 'improving' the cable run with CAT6 segments. Have the telco simply configure the CPE side of their interface facility to permit a longer run and tolerance. You'll be fine after that.

Ed Vaughn, MBSWWYPBX