The Reading striker rejected a 12-month contract extension at the Madejski, and the offer of a longer term deal at Portman Road probably swung it for the 31 year old.
Town are also in talks with Swindon Town hot-shot Sam Parkin over a move to Suffolk, and there are rumours circulating that he may be unveiled to the press at the same time as Forster.
This is probably not the case, with the former Chelsea forward discussing possible moves to other Championship clubs. Watford and local rivals Norwich have been mentioned and Parkin has said that he'll take his time making his decision.