The Nortel Ethernet Routing Switch (ERS) 4500 Series is a stackable, scalable and economical product that provides the resiliency, security and convergence-readiness required by application-driven and constantly changing enterprise networks. The series delivers flexible Ethernet switching with both Fast Ethernet or Gigabit Ethernet models as well as Power over Ethernet (PoE) options for simplified network deployments - helping to drive lower total cost of ownership.