# US 2014/0192807 A1 · Packet forwarding system, control apparatus, packet forwarding method, and program > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192807 A1 - Document ID: US20140192807A1 - Status: Published application - Kind: A1 - Application number: 14/237,849 - Filed: 2012-08-10 - Published: 2014-07-10 - Earliest claimed: 2011-08-11 - Assignees: NEC Corporation - Inventors: Takahiro Otake - Web page: https://patentgrep.com/patent/US20140192807A1 ## CPC - H04L 47/10: Flow control; Congestion control - H04L 12/18: for broadcast or conference {, e.g. multicast} - H04L 45/16: Multipoint routing - H04L 45/42: Centralised routing - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A packet forwarding system includes: first relay apparatuses that are connected to each other; a second relay apparatus that includes ports and that is connected to first relay apparatuses; and a control apparatus that configures a trunk serving as virtual logical link by using physical links among first and second relay apparatuses. The control apparatus determines a designated port from ports of first relay apparatuses included in the trunk. When a relay apparatus included in the first relay apparatuses receives a predetermined control target packet, the control apparatus controls the first relay apparatuses to transmit a received control target packet via relay apparatus having the designated port. ## Claims ### Claim 1 A packet forwarding system, comprising: a group of first relay apparatuses that are connected to each other; a second relay apparatus that comprises a plurality of ports and that is connected to each of the first relay apparatuses; and a control apparatus that configures a trunk(s) serving as a virtual logical link(s) by using physical links among the first and second relay apparatuses; wherein the control apparatus determines a designated port from ports of the first relay apparatuses included in the trunk; and wherein, when a relay apparatus included in the group of first relay apparatuses receives a predetermined control target packet, the control apparatus controls the group of first relay apparatuses to transmit the received control target packet via a relay apparatus having the designated port. ### Claim 2 (depends on 1) The packet forwarding system according to claim 1; wherein the predetermined control target packet comprises a broadcast packet or a multicast packet. ### Claim 3 (depends on 1) The packet forwarding system according to claim 1; wherein each of the first relay apparatuses comprises: a member port that is connected to the second relay apparatus and that can be a candidate for the designated port; a stack link port(s) that is connected to another first relay apparatus(es); and an output port(s) that is connected to an apparatus(es) other than the first and second relay apparatuses. ### Claim 4 (depends on 1) The packet forwarding system according to claim 1; wherein the control apparatus comprises: a trunk information storage unit that stores trunk configuration information including information about ports of the first relay apparatuses; and a trunk control command generation unit that selects the designated port by referring to the trunk information storage unit and that controls the first relay apparatuses. ### Claim 5 (depends on 1) The packet forwarding system according to claim 1; wherein the trunk control command generation unit changes a packet forwarding path that leads to a relay apparatus having the designated port among the first relay apparatuses, based on a failure status of a stack link(s) among the first relay apparatuses. ### Claim 6 (depends on 1) The packet forwarding system according to claim 1; wherein the number of the first relay apparatuses is at least three and the first relay apparatuses are connected to each other in a ring structure. ### Claim 7 (depends on 1) The packet forwarding system according to claim 1; wherein each of the first relay apparatuses comprises a forwarding table that stores entries, in which a packet reception port, a matching condition for determining the predetermined control target packet, and an output port are associated with each other; and wherein the control apparatus controls each of the first relay apparatuses by rewriting a forwarding table of each of the first relay apparatuses. ### Claim 8 A control apparatus, which is connected to a group of first relay apparatuses that are connected to each other and a second relay apparatus that comprises a plurality of ports and that is connected to each of the first relay apparatuses and which configures a trunk(s) serving as a virtual logical link(s) by using physical links among the first and second relay apparatuses; wherein the control apparatus determines a designated port from ports of the first relay apparatuses included in the trunk; and wherein the control apparatus controls, when a relay apparatus included in the group of first relay apparatuses receives a predetermined control target packet, the group of first relay apparatuses to transmit the received control target packet via a relay apparatus having the designated port. ### Claim 9 A packet forwarding method, comprising: by a control apparatus, which is connected to a group of first relay apparatuses that are connected to each other and a second relay apparatus that has a plurality of ports and that is connected to each of the first relay apparatuses and which configures a trunk(s) serving as a virtual logical link(s) by using physical links among the first and second relay apparatuses, determining a designated port from ports of the first relay apparatuses included in the trunk; and controlling, when a relay apparatus included in the group of first relay apparatuses receives a predetermined control target packet, the group of first relay apparatuses to transmit the received control target packet via a relay apparatus having the designated port. ### Claim 10 A non-transitory computer-readable recording medium storing a program, causing a computer constituting a control apparatus, which is connected to a group of first relay apparatuses that are connected to each other and a second relay apparatus that comprises a plurality of ports and that is connected to each of the first relay apparatuses and which configures a trunk(s) serving as a virtual logical link(s) by using physical links among the first and second relay apparatuses, to execute: determining a designated port from ports of the first relay apparatuses included in the trunk; and controlling, when a relay apparatus included in the group of first relay apparatuses receives a predetermined control target packet, the group of first relay apparatuses to transmit the received control target packet via a relay apparatus having the designated port.