Multi-domain controller, single-domain controller, software defined optical network system and method

A multi-domain controller, at least comprising:

• a virtual network service manager arranged to:
• process a cross-domain or single-domain Virtual Optical Network Service (VONS) request sent from an application layer and divide the cross-domain VONS request into an inter-domain part to be processed and an intra-domain part to be processed, the intra-domain part including multiple intra-single-domain parts;
• wherein the inter-domain part of the VONS request is processed by the multi-domain controller, wherein the multi-domain controller is arranged to:
• for a service request with a Bandwidth On Demand (BOD) connection attribute in the cross-domain VONS request, forward the service request with the BOD connection attribute to a routing connection controller, and for a service request with an Optical Virtual Private Network (OVPN) attribute in the cross-domain VONS request, perform OVPN service processing which includes establishment and deletion according to acquired virtual network layer resources;
• and
• wherein each of the intra-single-domain parts of the cross-domain VONS request is issued to each single-domain controller by the virtual network service manager of the multi-domain controller through a Path Computation Element Protocol(PCEP)+/OPENFLOW/Restful/Simple Network Management Protocol (SNMP) protocol controller.