A communication system includes a local unit that has a lower data link
layer and a session layer running a data pass-through application and a
user interface. The data pass-through application lets the data link
layer in the local unit pass data through to a remote unit. The remote
unit has a lower data link layer and a session layer executing a user
interface. When the data link layer detects that the session layer is
unstable and/or locked up, the data link layer transmits a disconnect
request to the local unit's data link layer. All further user data sent
to the local unit's data link layer is routed to the local unit's user
interface.