The <rpc> element is used for enclosing a NETCONF request sent from the client to the server.
Every <rpc> element contains a mandatory attribute, the message-id. This attribute has a unique value for every RPC request, and is used to associate every RPC request with the corresponding response. The message-id value is a monotonically increasing integer string. The maximum length of the string is 4095 characters. If the message-id is not present in the RPC request, the server rejects the request by returning an <rpc-error> with an <error-tag> element set to “missing-attribute”.
If there are any additional attributes present in the RPC request, the NETCONF server returns them unmodified in the corresponding RPC reply.