map  {
      my( $v, $k ) = keys %$_;
      my $val = $v =~ /pack/ ? $k : $v;
      my( $src, $srcP, $dst, $dstP ) = split /:/, $val;
      my( $low, $high ) = sort { $a cmp $b } ( "$src:$srcP", "$dst:$dstP" );
      my $key = $high . '-' . $low;
      [ $key, $srcP, $_ ]
    }