What causes the "You've reached your download limit or you maybe using a shared IP address" message
As far as I understand, Globe and Smart doesn't assign unique IP addresses to their subscribers. IP addresses are comparable to street addresses. A house could be numbered 521 and the neighbor numbered as 522. It's basically the same with IP addresses for computers. Your computer could be IP'd as 18.104.22.168 and your neighbor's could be 22.214.171.124.
Now Globe and Smart, like mentioned above, doesn't assign unique IP addresses to their subscribers. Meaning that if Globe or Smart has 10,000 subscribers in a given area, all those subscribers are using the same IP address. If you have an IP address of 192.22.333.338, the people around you also are using the same. This is a huge problem to subscribers who use file hosting sites since these services doesn't recognize shared IP addresses even on different computers.
This only means that if one subscriber among the 10,000 subscribers in a given area downloads something at a given file hosting service, that already counts as one download from one IP address and the remaining 9,999 subscribers would have to wait for the download limit to be lifted and hopefully be the first one among the 9,999 subscribers to download next.
Shared IP problems doesn't only apply to downloading to file hosting sites. This nuisance also extends to other IP addresses banning your IP address from their domain temporarily or permanently. For example, if a person stirred trouble at a given website and your IP address has been permanently banned from it, other subscribers who are using the shared IP as you are would also be banned from that website, even if they are completely different users with completely different accounts from the one banned.
Now, this would be no problem if only Globe and Smart assigned static or unique dynamic IP addresses to their users like the telco giant PLDT. If you have PLDT as your ISP then chances are you've never experienced this shared IP trouble. It's also worth noting that while prepaid dial-up services offer slower internet speed, at least they provide users with unique dynamic IP addresses.
What are static and dynamic IP addresses
Simply put, static IP addresses are fixed IP addresses that is assigned to one subscriber only. Your address is unique and is never the same with anyone else in any given area or time. Unique dynamic IP addresses on the other hand are IP addresses that always change whenever you turn on your internet connection but is never the same with anyone else in any given area or time. It's akin to having your street address changed every time you enter your house.
How to fix shared IP address issues
I guess there's a plethora of ways to fix this shared IP address issue, but I only know of two. I'm not a technical guy, but I know enough to run and do things myself at the most.
1) Fixing the shared IP address issue for downloads
If you love to download stuff from file hosting sites but always encounter the shared IP error, you can try using free premium link generators service found everywhere on the internet. These services, such as shimory.com, offer premium download links at high speeds which coincidentally makes file hosting sites disregard shared IP addresses because the service itself is a registered premium user. Most premium link generators offer up to three simultaneous downloads on one computer.
Working premium link generators for 2011
2) Fixing the shared IP address issue for banned IPs or downloads
If you want to enter a website a shared IP has been banned from, you can use free IP anonymizers. Just google for them and you'll find one in no time. You'll just need to enter the hyperlink or web address of the said site onto the anonymizer service and you'll be surfing a site anonymously.
This could also be used as an alternate to downloading a file or as simply surfing anonymously.
Best free internet anonymizers
I hope that I helped you with this simple how-to guide. There are more ways on how to fix shared IP addresses like using internet proxies or using veiled ISPs but I'm not in a position to discuss them as I lack the knowledge yet. I'll update this post once I get the know-how.
'Till my next installment.