# US 10,374,830 B1 · WAN-span LAN (WSL) networking technology > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,830 B1 - Document ID: US10374830B1 - Status: Granted - Kind: B1 - Application number: 15/648,734 - Filed: 2017-07-13 - Granted: 2019-08-06 - Earliest claimed: 2016-07-17 - Assignees: FatPipe, Inc. - Applicants: FatPipe, Inc. - Inventors: Sanchaita Datta; Bhaskar Ragula; Xiaoxiong Fan; Sankhadip Sengupta - Web page: https://patentgrep.com/patent/US10374830B1 ## CPC - H04L 12/4633: {Interconnection of networks using encapsulation techniques, e.g. tunneling} - H04L 12/4604: {LAN interconnection over a backbone network, e.g. Internet, Frame Relay} - H04L 12/4625: {Single bridge functionality, e.g. connection of two networks over a single bridge} - H04L 12/4641: {Virtual LANs, VLANs, e.g. virtual private networks [VPN] (LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272)} - H04L 2212/00: Encapsulation of packets - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Tools and technologies geographically extend local area networks by transparently inserting transmission of encapsulated local area network frames over wide area network connections. Some devices receive frames from a switch or other physically addressed device using layer 2 protocols, encapsulate them, and send them over a wide area network to a similar remote device which decapsulates the frames and forwards them using layer 2 protocols. Load balancing, quality of service, compression, encryption, and other packet processing may be performed on the encapsulated packets. ## Claims ### Claim 1 A networking process, the process performed in an environment which includes MAC (media access control) addresses, IP (internet protocol) items, a WAN (wide area network), and SD-WAN (software-defined wide area network) or WSL (WAN-spanning LAN) devices, the process comprising: receiving a layer 2 frame from a first switch in a kernel at a first WSL device, the layer 2 frame having a switch source MAC address which identifies the first switch as a frame source, a switch destination MAC address which identifies a frame destination, and a payload which includes a user frame, the user frame having user source MAC address which identifies a user source computer, a user destination MAC address which identifies a user destination computer, and a payload which includes a user IP datagram; obtaining within the first WSL device an IP address of a second WSL device which is separated from the first WSL device by a WAN; adding an IP header to the layer 2 frame within the first WSL device, thereby creating within the first WSL device a layer 3 packet which contains the layer 2 frame, the packet IP header having a source IP address which is an IP address of the first WSL device, the layer 3 packet IP header having a destination IP address which is the obtained IP address of the second WSL device; reinjecting the layer 2 frame into the kernel within the layer 3 packet, for processing as part of the layer 3 packet; and transmitting the layer 3 packet toward the WAN through a WAN interface of the first WSL device. ### Claim 2 (depends on 1) The networking process of claim 1, further comprising: receiving the layer 3 packet at the second WSL device; stripping off the IP header, thereby retrieving the layer 2 frame which contains the user IP datagram; and sending the layer 2 frame from the second WSL device toward a second switch, the second switch having the switch destination MAC address as a MAC address. ### Claim 3 (depends on 1) The networking process of claim 1, wherein obtaining the IP address of the second WSL device comprises performing at least one of the following: load balancing, failing over, or implementing a quality of service criterion. ### Claim 4 (depends on 1) The networking process of claim 1, wherein the layer 2 frame is characterized in at least one of the following ways: the layer 2 frame is an Ethernet frame; the layer 2 frame is a data link layer frame; the layer 2 frame includes a VLAN (virtual local area network) tag; the layer 2 frame is a TRILL (transparent interconnection of lots of links) frame; the layer 2 frame is an IS-IS (intermediate system to intermediate system) frame; the layer 2 frame is an SPB (shortest path bridging) frame. ### Claim 5 (depends on 1) The networking process of claim 1, wherein the layer 3 packet is a virtual extensible local area network packet. ### Claim 6 (depends on 1) The networking process of claim 1, wherein the process further comprises establishing a virtual private network tunnel between the first WSL device and the second WSL device, and wherein transmitting comprises transmitting the layer 3 packet through the WAN interface into the virtual private network tunnel. ### Claim 7 (depends on 1) The networking process of claim 1, wherein receiving the layer 2 frame comprises receiving the layer 2 frame in a memory buffer, and wherein adding the IP header to the layer 2 frame within the first WSL device comprises modifying the memory buffer to contain the layer 3 packet and then submitting the layer 3 packet for processing by a kernel packet processing framework. ### Claim 8 (depends on 1) The networking process of claim 1, wherein the process comprises adding an IP header to the layer 2 frame with the destination IP address and adding a UDP (user datagram protocol) header which creates the layer 3 packet as a VXLAN (virtual extensible local area network) packet. ### Claim 9 (depends on 1) The networking process of claim 1, wherein the process further comprises aggregating data from multiple layer 2 frames into the layer 3 packet. ### Claim 10 A computer-readable storage medium configured with software which upon execution by a first device having at least one processor performs a networking process, the networking process comprising: receiving a layer 2 frame in a kernel at the first device, the layer 2 frame having a switch source physical address which identifies a first switch as a frame source, a switch destination physical address which identifies a frame destination, and a payload which includes a user frame, the user frame having user source physical address which identifies a user source computer, a user destination physical address which identifies a user destination computer, and a payload which includes a user IP (internet protocol) datagram; obtaining within the first device an IP address of a second device which is physically separated from the first device by at least one mile; adding an IP header to the layer 2 frame within the first device, thereby creating within the first device a layer 3 packet which contains the layer 2 frame, the packet IP header having a source IP address which is an IP address of the first device, the packet IP header having a destination IP address which is the obtained IP address of the second device; reinjecting the layer 2 frame into the kernel within the layer 3 packet, for processing as part of the layer 3 packet; and transmitting the layer 3 packet toward the second device through a wide area network interface of the first device. ### Claim 11 (depends on 10) The computer-readable storage medium of claim 10, wherein the networking process further comprises: receiving the layer 3 packet at the second device; stripping off the IP header, thereby retrieving the layer 2 frame which contains the user IP datagram; and sending the layer 2 frame from the second device toward a second switch, the second switch having the switch destination physical address as a physical address. ### Claim 12 (depends on 10) The computer-readable storage medium of claim 10, wherein the layer 2 frame is characterized in at least two of the following ways: the layer 2 frame is an Ethernet frame; the layer 2 frame is a data link layer frame; the layer 2 frame includes a VLAN (virtual local area network) tag; the layer 2 frame is a TRILL (transparent interconnection of lots of links) frame; the layer 2 frame is an IS-IS (intermediate system to intermediate system) frame; the layer 2 frame is an SPB (shortest path bridging) frame. ### Claim 13 (depends on 10) The computer-readable storage medium of claim 10, wherein the networking process further comprises establishing a virtual private network tunnel between the first device and the second device, and wherein transmitting comprises transmitting the layer 3 packet through the wide area network interface into the virtual private network tunnel. ### Claim 14 (depends on 10) The computer-readable storage medium of claim 10, wherein the networking process comprises adding an IPv4 header to the layer 2 frame with the destination IP address and adding a UDP (user datagram protocol) header which creates the layer 3 packet as a VXLAN (virtual extensible local area network) packet. ### Claim 15 A first network extension device comprising: at least one processor; a memory in operable communication with the processor; and a WSL module comprising WSL hardware operating with WSL software to perform WSL operations which extend LAN communication across a WAN, “LAN” denoting “local area network”, “WAN” denoting “wide area network”, “WSL” denoting “WAN-spanning LAN”, the WSL module comprising a network interface card and a portion of the memory which is configured the WSL software, the WSL operations comprising operations which (a) add an IP header to a LAN frame received in a kernel of the first network extension device, the LAN frame having a switch source physical address which identifies a first switch as a source of the LAN frame, the LAN frame being a layer 2 frame, the first switch physically located within two miles of the first network extension device, the IP header having a destination IP address which identifies a second network extension device physically located more than five miles away from the first network extension device, (b) create a layer 3 packet containing the IP header and the LAN frame, (c) reinject the LAN frame in the kernel within the layer 3 packet, for processing as part of the layer 3 packet, and (d) transmit the layer 3 packet toward the second network extension device through the wide area network interface of the first network extension device. ### Claim 16 (depends on 15) The first network extension device of claim 15, in combination with the second network extension device. ### Claim 17 (depends on 15) The first network extension device of claim 15, wherein as part of the WSL operations the WSL module frame adds the IP header and transmits a LAN frame which is a broadcast frame or a multicast frame or both. ### Claim 18 (depends on 15) The first network extension device of claim 15, further comprising a packet processing framework which is configured to perform one or more of load balancing, failover, compression, or encryption. ### Claim 19 (depends on 15) The first network extension device of claim 15, wherein the first network extension device comprises at least two wide area network interfaces and a local area network interface. ### Claim 20 (depends on 15) The first network extension device of claim 15, wherein as part of the WSL operations the WSL module discards a LAN frame which has a source address and a destination address on the same LAN segment as one another.