The old analog systems used the hard lines for connecting between nodes. The uplink/downlink site connected to hard lines to route calls to regular users. The hardlines are not used as much as they once were. They are still available in some older buildings and sites, but mostly have been upgraded to VOIP phones and connected via ethernet vice the older RJ11 connections that we used to see. Most everything now has upgraded to RJ45 connectors and ethernet switches/routers.