Of course this private network doesn't have to be a separate line or fiber.

The town once served by two stations on separate lines.

I'll call on a separate line and pick them up.

My phone had a separate line and it might still be functioning.

A separate, more commercial line was shown privately to the stores.

Social services personnel are available on that number which has 19 separate lines.

Men and women form separate lines down the hall or in an open place of beaten earth, one group facing the other.

She pressed a separate line, about to punch in 911.

And if you want your own separate line with a different number, that, too, is of course possible.

This is very useful when performing a particular action on each separate line of the field.