sub PerformSS {
   my $self = shift;
   my ($cmdArg) = @_;
   
   my $cmd = "ss " . $cmdArg;
   my $status = 0;
   if ($self->doSS) {
      $status = system("$cmd 1>>$errorfile 2>&1");
      $self->checkError($status, "PerformSS $cmd failed $status $!");
      $self->trace("--- completed $cmd ---\n");
   } else {
      $self->trace("--- PerformSS did not $cmd ---\n");
   }
   return $status;
}