#!/usr/bin/perl 
use strict;
use warnings;
use Data::Dumper;
use Math::BigInt lib => 'GMP';

my @speeds = 
( '10Mbps', '115kbps', 'Flash', '2Mbps', 'T1 LINE', 'Shocker' );

my ( @clean_speeds, @sorted_speeds );

my $speed_re = {
    'BPS' => qr/(\d+)\s*([KMGT])BPS/,    # 10MBPS
    'T'   => qr/T(\d)\s*\w*/,            # T1 LINE
};

my $bps  = Math::BigInt->new('2')->bpow(10);

my $unit = {
    'BPS' => {
        K => $bps->copy->bpow(0),
        M => $bps->copy->bpow(1),
        G => $bps->copy->bpow(2),
        T => $bps->copy->bpow(3),
    },
    # ref => http://ckp.made-it.com/t1234.html
    'T' => {
        1 => Math::BigInt->new('1544'),      # T1 = 1544   kbps
        2 => Math::BigInt->new('6312'),      # T2 = 6312   kbps
        3 => Math::BigInt->new('44736'),     # T3 = 44736  kbps
        4 => Math::BigInt->new('274760'),    # T4 = 274760 kbps
    },
};

for (@speeds) {
    my $speed = uc $_;
    $speed =~ /(?:$speed_re->{'BPS'}|$speed_re->{'T'})/
      ? push @clean_speeds, $speed
      : warn "Unmatched speed: $speed\n";
}

@sorted_speeds = 
sort { net_speed($a) <=> net_speed($b) } @clean_speeds;

print Dumper \@sorted_speeds;

sub net_speed {
    my $speed = shift;
    if ( $speed =~ /$speed_re->{'BPS'}/ ) {
        Math::BigInt->new( $unit->{'BPS'}->{$2} )->bmul($1);
    }
    elsif ( $speed =~ /$speed_re->{'T'}/ ) {
        Math::BigInt->new( $unit->{'T'}->{$1} );
    }
}
__END__
Output:
------
Unmatched speed: FLASH
Unmatched speed: SHOCKER
$VAR1 = [
          '115KBPS',
          'T1 LINE',
          '2MBPS',
          '10MBPS'
        ];