Anyone have any clues about how these lines are engineered these days? Or has everyone that knew anything about them retired to sunny climes? I would think that in the era of modern ISDN SS7 networks that these chokes would no longer be needed to manage traffic loads between Central offices. If they can be provisioned as something besides analog lines without caller id? I am just throwing this out there. Wondering if this technology can be updated into the 21st century. Thanks for any input.