A network management device comprising: a management server component configured with network configuration NETCONF, protocol; and an authorization client component configured with a remote authorization protocol; wherein the management server component is configured to: receive a user operation request from a management agent , wherein the operation request indicates one or more operations; convert the operation request to one or more pairs of operation identifications and Xpaths, wherein the Xpath represents an object on which the operation is to be performed; and send the one or more pairs of operation identifications and Xpaths to the authorization client component ; and the authorization client component is configured to: send an authorization request including the one or more pairs of operation identifications and Xpaths to a centralized authorization server ; obtain, for the user operation request, an authorization information from the centralized authorization server ; send the authorization information to the management server component ; and the management server component is further configured to: generate an operation result according to the authorization information; and send the operation result to the management agent . a management server component configured with network configuration NETCONF, protocol; and an authorization client component configured with a remote authorization protocol; wherein the management server component is configured to: receive a user operation request from a management agent , wherein the operation request indicates one or more operations; convert the operation request to one or more pairs of operation identifications and Xpaths, wherein the Xpath represents an object on which the operation is to be performed; and send the one or more pairs of operation identifications and Xpaths to the authorization client component ; and receive a user operation request from a management agent , wherein the operation request indicates one or more operations; convert the operation request to one or more pairs of operation identifications and Xpaths, wherein the Xpath represents an object on which the operation is to be performed; and send the one or more pairs of operation identifications and Xpaths to the authorization client component ; and the authorization client component is configured to: send an authorization request including the one or more pairs of operation identifications and Xpaths to a centralized authorization server ; obtain, for the user operation request, an authorization information from the centralized authorization server ; send the authorization information to the management server component ; and send an authorization request including the one or more pairs of operation identifications and Xpaths to a centralized authorization server ; obtain, for the user operation request, an authorization information from the centralized authorization server ; send the authorization information to the management server component ; and the management server component is further configured to: generate an operation result according to the authorization information; and send the operation result to the management agent . generate an operation result according to the authorization information; and send the operation result to the management agent . <EOS>