The Red Lion N-Tron® Series 7900CPU is a modular central processing unit made for use with the 9000 series modular Ethernet switches. A central processing unit, or processor, is what allows computing functions to be carried out. It takes the input instructions that it receives and implements them. In this case, it works with the other modular Ethernet switches it is connected to. It sits in the 9000BP backplane, which has slots for 4 other switches. The modular design makes it easier to customize based on the needs of the network.

The 7900CPU is gigabit capable, with slots for two SFP transceivers. It has a built-in temperature sensor, as central processing units tend to heat up when running. It is made for fully managed switches, with management features such as SNMP (Simple Network Management Protocol), IGMP (Internet Group Management Protocol) Snooping, port mirroring, trunking, and N-View port monitoring. SNMP assists in configuring the switch. IGMP Snooping forwards traffic from remembered group addresses. With port mirroring, the traffic from one port can copied and sent to another port. Trunking means that more than one port can be linked together to act as a single uplink. N-View port monitoring simply refers to the programs and functions that allow a user to check on network traffic and the status for each port.

The 9000BP backplane and 9000 series modular switches, as well the SFP transceivers, are all sold separately to make it easier to customize your setup. The 9000 series Ethernet switches must be used with the 7900CPU in order to function properly. These modular Ethernet switches are ideal for security and surveillance applications. It can be used as part of a ring topology, particularly a tree topology, in which the 7900CPU is connected to other Ethernet switches which each control their own devices within a network. It can also be used in a redundant ring, in which the switches are all connected to each other and can perform the same operations in the event that one is not available.