When is the NFL trade deadline? What to know about Buffalo Bills

Buffalo is 6-1 after beating the Baltimore Ravens 36-10 on Sunday, but the Bills still have some questions on defense as they prepare for the second half of the regular season. The Bills lead the NFL in scoring at 33.3 points per game but rank 24th in points allowed at 25.9 per game. Safety, cornerback and inside linebacker are among the positions where Buffalo could look for help. The Bills' limited salary cap space could make a major acquisition difficult.