my @q = qw(workstation_1_1 workstation_1_2
        voiceserver_1_2 voiceserver_1_1);

@q =
  map { join '_', @$_ }
  sort {     $a->[1] <=> $b->[1] or $a->[2] <=> $b->[2] 
          or $a->[0] cmp $b->[0] }
  map  { [ split /_/ ] } @q;

use Data::Dumper;
print Dumper( \@q );
__OUTPUT__
'voiceserver_1_1',
'workstation_1_1',
'voiceserver_1_2',
'workstation_1_2'
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