Explanation
OOB management is used for devices at the headquarters and is accomplished by connecting dedicated
management ports or spare Ethernet ports on devices directly to the dedicated OOB management network
hosting the management and monitoring applications and services. The OOB management network can be
either implemented as a collection of dedicated hardware or based on VLAN isolation.
Source:
http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Security/SAFE_RG/SAFE_rg/chap9.html