# US 9,521,014 B2 · Network system and data transmission method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,521,014 B2 - Document ID: US9521014B2 - Status: Granted - Kind: B2 - Application number: 14/745,619 - Filed: 2015-06-22 - Published: 2015-12-24 - Granted: 2016-12-13 - Earliest claimed: 2014-06-23 - Assignees: Accton Technology Corporation - Applicants: Accton Technology Corporation - Inventors: Ran-Yih Wang - Web page: https://patentgrep.com/patent/US9521014B2 ## CPC - H04L 12/64: Hybrid switching systems - H04L 12/2854: {Wide area networks, e.g. public data networks} - H04L 12/4633: {Interconnection of networks using encapsulation techniques, e.g. tunneling} - H04L 41/0654: using network fault recovery (ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437) - H04L 41/0663: Performing the actions predefined by failover planning, e.g. switching to standby network elements - H04L 49/70: {Virtual switches} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A data transmission method and network system are provided. The data transmission method is applied to a data center when a data packet can't be transmitted from the first virtual machine of a first server to the second virtual machine of a second server due to the data center occurring lookup fail. The data transmission method includes the steps of transmitting the data packet through a downlink port of a first TOR switch according to an ISID; encapsulating the data packet and setting a CVID to a first value; transmitting the encapsulated data packet to a first spine switch; and transmitting the encapsulated data packet to the second virtual machine by the first spine switch according to the flooding information, wherein the flooding information is generated according to an f-BVID. ## Claims ### Claim 1 A network system, applied to perform data transmission in a data center, the network system comprising: a controller, generating flooding information according to a flooding-backbone virtual local area network identifier (f-BVID); a first server, comprising a first virtual machine corresponding to a first Tenant ID, wherein the first virtual machine generates and outputs a data packet; a second server, comprising a second virtual machine corresponding to the first Tenant ID; a first Top-of-Rack (TOR) switch, connected with the first server and receiving the data packet from the first server; a second TOR switch, connected with the second server; and a first spine switch, connected with the first TOR switch and the second TOR switch, configured to receive the data packet from the first TOR switch and transmit the data packet to the second TOR switch according to flooding information, wherein when the first TOR switch is unable to transmit the data packet to the second virtual machine due to the first TOR switch occurring lookup fail, the first TOR switch transmits the data packet through a downlink port of the first TOR switch according to a service instance identifier (ISID), and the first TOR switch encapsulates the data packet, sets a customer virtual local area network identifier (CVID) as a first value, and transmits the encapsulated data packet to the first spine switch. ### Claim 2 (depends on 1) The network system of claim 1, wherein the first spine switch transmits the encapsulated data packet to the second TOR switch and the second TOR switch transmits the encapsulated data packet to the second virtual machine of the second server according to the ISID. ### Claim 3 (depends on 2) The network system of claim 2, wherein the first TOR switch and the second TOR switch determines whether the connected server comprises the virtual machine corresponding to the first Tenant ID, and the first TOR switch and the second TOR switch transmit the encapsulated data packet to the second virtual machine corresponding to the first Tenant ID. ### Claim 4 (depends on 1) The network system of claim 1, further comprising: a third TOR switch, connected with the first server and the first spine switch, wherein the first TOR switch and the third TOR switch are configured in a first branch, and the first TOR switch and the second TOR switch correspond to the first value; and a fourth TOR switch, connected with the second server and the first spine switch, wherein the second TOR switch and the fourth TOR switch are configured in a second branch, and the third TOR switch and the fourth TOR switch correspond to a second value of the CVID, wherein when the CVID is set as the first value, merely the first TOR switch and the second TOR switch corresponding to the first value transmit the data packet; and wherein when the CVID is set as the second value, merely the third TOR switch and the fourth TOR switch corresponding to the second value transmit the data packet. ### Claim 5 (depends on 4) The network system of claim 4, further comprising: a second spine switch, connected with the first TOR switch, the second TOR switch, the third TOR switch and the fourth TOR switch, wherein when a link fail has occurred in the first spine switch and the first branch and/or second branch, the second spine switch supersedes the spine switch to transmit the data packet. ### Claim 6 (depends on 1) The network system of claim 1, wherein when the first TOR switch encapsulates a MAC header into the data packet, the first TOR switch transforms a BVID into the f-BVID according to the MAC header. ### Claim 7 (depends on 1) The network system of claim 1, wherein when a link status is changed, the first spine switch transmits a link status packet to the controller to update and maintain flooding information. ### Claim 8 A data transmission method comprising: transmitting a data packet through a downlink port of a first Top-of-Rack (TOR) switch according to a service instance identifier (ISID); encapsulating the data packet and setting a customer virtual local area network identifier (CVID) as a first value; transmitting the encapsulated data packet to a first spine switch; and transmitting the encapsulated data packet to a second virtual machine by the first spine switch according to flooding information, wherein the flooding information is generated according to a flooding-backbone virtual local area network identifier (f-BVID), wherein the data transmission method is applied to a data center when the data packet is unable to be transmitted from a first virtual machine of a first server to the second virtual machine of a second server due to the data center occurring lookup failure. ### Claim 9 (depends on 8) The data transmission method of claim 8, wherein transmitting the encapsulated data packet to the second virtual machine by the first spine switch according to the flooding information comprises: transmitting the encapsulated data packet to a second TOR switch by the first spine switch; and transmitting the encapsulated data packet to the second virtual machine of the second server by the second TOR switch according to the ISID. ### Claim 10 (depends on 9) The data transmission method of claim 9, wherein the second TOR switch determines whether the server which the second TOR switch connects with comprises the virtual machine corresponding to the first Tenant ID and transmits the encapsulated data packet to the second virtual machine corresponding to the first Tenant ID. ### Claim 11 (depends on 10) The data transmission method of claim 10, wherein the data center further comprises a third TOR switch and a fourth TOR switch, wherein the third TOR switch is connected with the first server and the first spine switch, and the first TOR switch and the third TOR switch are configured in a first branch, and the first TOR switch and the second TOR switch correspond to the first value; and the fourth TOR switch is connected with the second server and the first spine switch, and the second TOR switch and the fourth TOR switch are configured in a second branch, and the third TOR switch and the fourth TOR switch correspond to a second value of the CVID; and wherein when the CVID is set as the first value, merely the first TOR switch and the second TOR switch corresponding to the first value transmit the data packet; and when the CVID is set as the second value, merely the third TOR switch and the fourth TOR switch corresponding to the second value transmit the data packet. ### Claim 12 (depends on 11) The data transmission method of claim 11, wherein when a link fail has occurred in the first spine switch and the first branch and/or second branch, a second spine switch supersedes the spine switch to transmit the data packet. ### Claim 13 (depends on 12) The data transmission method of claim 12, wherein when the first TOR switch encapsulates a MAC header into the data packet, the first TOR switch transforms a BVID into the f-BVID according to the MAC header. ### Claim 14 (depends on 8) The data transmission method of claim 8, wherein when a link status is changed, the first spine switch transmits a link status packet to the controller to update and maintain flooding information.