The modeling of active suspensions, or suspensions of self-propelling particles such as swimming microorganisms remains a great challenge despite their ubiquity in biological systems. The long-ranged fluid-mediated interactions between suspended particles in the low-Reynolds-number regime are known to give rise to collective motion and large-scale spatiotemporal coherent patterns. The mechanisms behind the emergence of collective dynamics and self-organization from individual interactions has received increasing attention in the past few years, and could provide valuable insight into the behavior of nonequiibrium dissipative systems. In this work, we use theory and numerical simulation to study the behavior of confined active suspensions, with emphasis on fore-aft asymmetric swimmers.