The signs of the iPhone 5 are upon us. Digitimes reports that Apple’s contract manufacturer Foxconn has significantly decreased their iPhone 4 shipments ahead of an expected October launch of the iPhone 5.

Reports are also beginning to surface suggesting that Apple’s supply of iPhone 4 units is becoming constrained on a global level. These are typical signs that Apple is about to refresh a product.

Prior reports have already indicated that manufacturers are already building and stockpiling iPhone 5 units at a rate of 150,000 per day, waiting for the iOS 5 Gold Master to be released by Apple in order to flash it on the new handsets. The same reports also suggest that Apple could product up to 6 million iPhone 5s for the month of September.