+ $user->sort('U') if (!$user->sort());
+ my $sort = $user->sort();
+ $dxchan = DXCommandmode->new($call, $conn, $user) if ($sort eq 'U');
+ $dxchan = DXProt->new($call, $conn, $user) if ($sort eq 'A');
+ die "Invalid sort of user on $call = $sort" if !$dxchan;