The operator can configure one or more instances of an H-OFS (using SNMP or CLI interfaces) with each instance controlled by an OF controller over a unique OF channel using OpenFlow protocol. One OF controller can control multiple H-OFS instances using dedicated channels, or a dedicated OF controller can be deployed per switch. For each switch, up to two OF controllers can be deployed for redundancy. If two controllers are programmed, they can operate in either OFPCR_ROLE_EQUAL roles or in OFPCR_ROLE_MASTER and OFPCR_ROLE_SLAVE roles. Figure: SR OS/switch OF controller/switch architecture overview shows this architecture.
Figure: SR OS/switch
OF controller/switch architecture overview
