Async call intermitent

[hashaari]

I have a funny problem concerning dial backup between HQ and branch using async/modem. The setup at HQ is E1 PRI and at branch is using modem connecting to aux port and configured so that only branch can call HQ. The problem is sometime it can get connected and sometime not. The symptoms observed is that even though the call have been disconnected, show line at HQ still show the line is active. Only after clear line is issued manualy can the call be made from branch. Any ideas, have suspicion that this relate to signalling on digital modem on E1 PRI card at HQ. Appreciate your experts opinion.

[hashaari]

1. I include the output of show line here on the HQ router as your guide

A 2/5 135 TTY 115200/115200- inout - - - 5 0 0/0 -

Ready

Even though the remote branch has disconnect the line is still active, I have to manually flush the line before the call can come through

2. FYI, my modemcap setting is this

modemcap entry mica001:FD=&F:AA=S0=1:ONH=H0:OFH=H1:CD=&C1:HFL=&K3

3. Is it my modem setting, I kinda suspect it.

Thanks