One comment [0] highlights a point in favor of the current implementation: > create a lock file for every dial-in line to prevent its use by programs looking f

One comment [0] highlights a point in favor of the current implementation: > create a lock file for every dial-in line to prevent its use by programs looking for a dial-out line. [0]: https://lwn.net/Articles/1042594/ https://lwn.net/Articles/1042594/