line protocol is down

[compath]

My line protocol went down the other day and have lost access to that route. I have a ser int from a 7204 connected to a CSU/DSU which is connected to another site with an access router. On the 7204 when I do a show int, the line protocol is down and when I do a debug ppp negotiation, there is no debugging at all, however for some mysterious reason I am able to ping my access router, I am just unable to get beyond the access router. Nothing has changed recently no new configs no cable swaps etc... I do see something in my config called IPCP which states that it is closed. When I look at my other routers it says that the IPCP is open. What is this and does this have anything to do with it. Any help would be appreciate Thanks!!

[HECTOR RIVERA]

On the 7204, what are the EIA stats shown at the bottom, I might guess that DCD and CTS are down and the rest are up.

If so, then because the line is down, the upper layer protocols will never initiate. In other words, if the Physical layer is down, PPP will never initiate as that is a layer 2 protocol and you would not see any PPP negotiation. Within PPP, there is LCP and NCP. Within NCP is the protocols negotiated such as IP, IPX, and so on. Internet Protocol Control Protocol is IPCP which is just IP negotiated during NCP. If you had IPX configured then you would see IPXCP, bandwidth on demand would be BACP, Appletalk would be ATCP, and so on.