Patent ID: 11962492
Assignee: KULCLOUD
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 4:
5. A timestamp assignment method of a packet of a network packet broker comprising:
obtaining information associated with a plurality of OpenFlow edge switches being connected to a plurality of legacy networks as a wireless access network or a wired access network and belonging to a first switch group;
generating routing information of the packet input to a switch within a second switch group including one or more of the plurality of OpenFlow edge switches, the second switch group considered as one or more virtual routers;
controlling manipulation and flow of packet in response to a request through the controller by:
mapping a plurality of network devices connected to the plurality of OpenFlow edge switches for generating legacy routing information of a flow processing query message based on information associated with the one or more virtual routers, to information of an external network connected directly to a virtual router of the one or more virtual routers;
synchronizing a packet time using a network device timestamp value;
replying, via a clock corresponding to a processor associated with the network packet broker, to the request with a time value;
storing, in a register corresponding to a processor associated with the switch of the second switch group, an elapsed time parameter Tp corresponding to a time that elapses from a reference time in the processor associated with the switch of the second switch group;
correcting, in response to the switch of the second switch group receiving a request for assignment of a timestamp of the packet, overflow of the elapsed time parameter Tp, wherein the correcting comprises:
obtaining the clock, by the switch of the second switch group;
updating the reference time in the processor associated with the switch in the second switch group to a reference time parameter Tb using the clock;
determining a current elapsed time parameter Tc time based on the reference time parameter Tb;
comparing the current elapsed time parameter Tc and the elapsed time parameter Tp in size;
updating, in response to the current elapsed time parameter Tc being less than the elapsed time parameter Tp, the reference time parameter Tb by adding the sum of the elapsed time parameter Tp and a correction value;
updating, in response to the current elapsed time parameter Tc being equal to or greater than the elapsed time parameter, Tp the reference time parameter Tb by adding the elapsed time parameter Tp to the reference time parameter Tb; and
storing the reference time parameter Tb as the timestamp in the packet.