# US 10,484,481 B2 · Fault tolerant, content download system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,484,481 B2 - Document ID: US10484481B2 - Status: Granted - Kind: B2 - Application number: 15/644,066 - Filed: 2017-07-07 - Published: 2017-10-26 - Granted: 2019-11-19 - Earliest claimed: 2015-01-08 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Dan Touitou; Eran Gampel; Adi Molkho - Web page: https://patentgrep.com/patent/US10484481B2 ## CPC - H04L 67/148: Migration or transfer of sessions - H04L 43/10: Active monitoring, e.g. heartbeat, ping or trace-route - H04L 67/06: specially adapted for file transfer, e.g. file transfer protocol [FTP] - H04L 69/40: for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection (management of faults, events, alarms or notifications in data switching networks H04L41/06) - H04L 69/163: In-band adaptation of TCP data exchange; In-band control procedures - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A network device to mitigate interruptions in content downloading from a content server to a client device in a client-server network is disclosed. The device includes a recovery module (RM) to migrate a data transfer connection from a first server to a second server responsive to detection of an interruption in data transfer from the first server. The migrated data transfer connection may include an instruction associated with an amount of data transferred prior to the interruption in data transfer. ## Claims ### Claim 1 A network device to mitigate interruptions in content downloading from a content server to a client device in a client-server network, the device comprising: a recovery module (RM) to migrate a data transfer connection of the client device from a first server to a second server responsive to detection of an interruption in data transfer from said first server while maintaining a same TCP connection of the client device, said migrated data transfer connection comprising an instruction associated with an amount of data transferred prior to said interruption in data transfer. ### Claim 2 (depends on 1) A network device according to claim 1 wherein said RM comprises a database for storing information associated with at least a portion of said data transfer connection. ### Claim 3 (depends on 2) A network device according to claim 2 wherein said information comprises any one of a HTTP request header, a HTTP response header, a client IP address, a client port, a server IP address, a server port, and a TCP sequence number. ### Claim 4 (depends on 1) A network device according to claim 1 wherein said RM comprises a traffic analyzer to analyze information associated with at least a portion of said data transfer connection. ### Claim 5 (depends on 1) A network device according to claim 1 wherein said RM comprises a connection monitor to proxy a portion of said data transfer connection to the RM. ### Claim 6 (depends on 1) A network device according to claim 1 wherein said RM comprises a connection monitor to instruct a network controller on the client-server network to alter packet destination information in said data transfer connection. ### Claim 7 (depends on 1) A network device according to claim 1 wherein said RM comprises an offloader interface to interface with a network controller on the client-server network. ### Claim 8 (depends on 1) A network device according to claim 1 wherein said RM comprises a server monitor to evaluate said detection of an interruption in data transfer from said first server. ### Claim 9 (depends on 8) A network device according to claim 8 wherein said evaluation is based on a measuring a timeout period following detection of said interruption. ### Claim 10 (depends on 8) A network device according to claim 8 wherein said evaluation is based on measuring a timeout period following polling of said first server. ### Claim 11 (depends on 1) A network device according to claim 1 wherein said RM comprises an offset evaluator to determine said amount of data transferred prior to said interruption in data transfer. ### Claim 12 (depends on 1) A network device according to claim 1 further comprising a network controller. ### Claim 13 (depends on 12) A network device according to claim 12 wherein said network controller is a Fast Path Offloading (FPO) controller. ### Claim 14 (depends on 12) A network device according to claim 12 wherein said network controller alters a client IP address and port in said migrated data transfer connection to said second server. ### Claim 15 (depends on 12) A network device according to claim 12 wherein said network controller alters a server IP address and port in said migrated data transfer connection to said second server. ### Claim 16 A method of mitigating interruptions in content downloading from a content server to a client device in a client-server network, the method comprising: detecting an interruption in a data transfer connection from the content server to the client; migrating said data transfer connection of the client device to a second server while maintaining a same TCP connection of the client device; and including in said data transfer connection information associated with an amount of content downloaded prior to the interruption. ### Claim 17 (depends on 16) The method according to claim 16 further comprising altering a client IP address and client port in data transferred from said second server to the client. ### Claim 18 (depends on 16) The method according to claim 16 further comprising altering a server IP address and server port in data transferred from the client to said second server. ### Claim 19 (depends on 18) The method according to claim 18 wherein said altering comprises a proxy replacing a server IP address and port of the first server with said IP address and server of said second server. ### Claim 20 (depends on 16) The method according to claim 16 further comprising probing the client to determine said amount of content downloaded prior to the interruption.