Susquehanna issued a note to its clients on Wednesday in which the firm said it is increasing its iPhone shipment forecast for Apple’s first fiscal quarter. The company originally expected Apple to ship 27.1 million iPhones during the quarter but has revised that figure up to 30.3 million units. “The revisions are based on positive sell-through data combined with recent supply-chain checks, which suggests that earlier component constraints have largely been resolved and build plans have increased for the fourth and first quarter,” the company explained in a note to clients. Susquehanna also said demand for the iPhone 4S remains strong and that the device continues to ship in 1-2 weeks from Apple’s website while retail stores are still “sold out for in-store reservation and pickup.” The firm’s predictions are certainly bullish; Apple sold 17.1 million iPhones during its fourth fiscal quarter. Still, other firms such as UBS predict that Apple will ship as many as 42.5 million iPhones during the December quarter.