# US 9,521,006 B2 · Duplicating digital streams for digital conferencing using switching technologies > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,521,006 B2 - Document ID: US9521006B2 - Status: Granted - Kind: B2 - Application number: 14/688,858 - Filed: 2015-04-16 - Published: 2015-08-06 - Granted: 2016-12-13 - Earliest claimed: 2001-04-30 - Assignees: Facebook, Inc. - Applicants: Facebook, Inc. - Inventors: Scott K. Brown - Web page: https://patentgrep.com/patent/US9521006B2 ## CPC - H04L 65/752: adapting media to network capabilities - H04L 12/1813: {for computer conferences, e.g. chat rooms (instant messaging H04L51/04; protocols for multimedia communication H04L65/1101; arrangements for multi-party communication H04L65/403; telephonic conference arrangements H04M3/56; television conference systems H04N7/15)} - H04L 12/1822: {Conducting the conference, e.g. admission, detection, selection or grouping of participants, correlating users to one or more conference sessions, prioritising transmission} - H04L 12/1827: {Network arrangements for conference optimisation or adaptation} - H04L 45/16: Multipoint routing - H04L 65/403: Arrangements for multi-party communication, e.g. for conferences (data switching systems for conference H04L12/18; arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities H04M3/56; television conferencing systems H04N7/15) - H04L 65/4038: with floor control - H04L 65/765: {intermediate} - H04N 7/147: {Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals (selecting H04Q)} - H04N 7/15: Conference systems - H04L 51/04: Real-time or near real-time messaging, e.g. instant messaging [IM] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Using switching technologies to duplicate packets of a digital stream (e.g., digital video stream) sent from one workstation to multiple recipient workstations, where the switching technologies enable the multiple streams sent from the switch to the recipient workstations to be generated from a single digital stream sent from the sending workstation to the switch. Data units, such as video data units, may be transmitted by using a switch to enable receipt of a stream of data units including a payload portion and an attribute portion from at least two conferencing participants. The switch is used to duplicate at least a subportion of the payload portion of a data unit within the stream of data units, and to enable access to the duplicated subportion of the data unit by two or more conferencing participants. ## Claims ### Claim 1 A method of transmitting data units, the method comprising: using a switch to receive a stream of data units including a payload portion and an attribute portion from at least two conferencing participants; using the switch to duplicate at least a subportion of the payload portion of a data unit within the stream of data units; and using the switch to enable access to the duplicated subportion of the data unit by two or more conferencing participants. ### Claim 2 (depends on 1) The method of claim 1 wherein the data unit includes an Internet Protocol packet. ### Claim 3 (depends on 2) The method of claim 2 wherein the attribute portion of the data unit includes an Internet Protocol header. ### Claim 4 (depends on 1) The method of claim 1 wherein the attribute portion of the data unit specifies one or more pieces of layer three information. ### Claim 5 (depends on 1) The method of claim 1 further comprising using the switch to generate and associate different attribute portions with duplicates of the payload portion generated by the switch. ### Claim 6 (depends on 5) The method of claim 5 wherein using the switch to associate different attribute portions with duplicates of the payload portion includes associating destination information that differs with the duplicates of the payload portion. ### Claim 7 (depends on 5) The method of claim 5 wherein using the switch to generate and associate different attribute portions includes changing an IP destination address. ### Claim 8 (depends on 7) The method of claim 7 wherein changing the IP destination address includes changing the IP destination address to an IP address corresponding to one or more conferencing participants to which access to the payload portion will be enabled. ### Claim 9 (depends on 1) The method of claim 1 wherein using the switch to duplicate at least the payload portion includes duplicating only the payload portion of the data unit. ### Claim 10 (depends on 1) The method of claim 1 wherein using the switch to duplicate includes using the switch to duplicate the payload portion and the attribute portion. ### Claim 11 (depends on 1) The method of claim 1 wherein a request is received from a device other than the conferencing participants. ### Claim 12 (depends on 11) The method of claim 11 further comprising receiving the request to receive the stream of data units from one of the two or more conferencing participants. ### Claim 13 (depends on 12) The method of claim 12 wherein using the switch to enable access to the duplicated subportion of the data unit includes enabling access to the conferencing participant in response to the request. ### Claim 14 (depends on 1) The method of claim 1 wherein using the switch to enable access to the duplicated subportion of the data unit by two or more conferencing participants includes transmitting two or more duplicated subportions to two or more conferencing participants using the switch. ### Claim 15 (depends on 14) The method of claim 14 wherein using the switch to enable access to the duplicated subportion of the data unit by two or more conferencing participants includes transmitting two or more duplicated subportions from a transmitting participant to all of the other conferencing participants using the switch. ### Claim 16 (depends on 14) The method of claim 14 wherein using the switch to enable access to the duplicated subportion of the data unit by two or more conferencing participants includes transmitting two or more duplicated subportions from all of the conferencing participants to each other of the conferencing participants using the switch. ### Claim 17 (depends on 16) The method of claim 16 wherein transmitting two or more duplicated subportions from all of the conferencing participants to all of the conferencing participants comprises enabling the switch to filter an originating stream so that a stream of data units from an originating conferencing participant is not transmitted back to the originating conferencing participant. ### Claim 18 (depends on 1) The method of claim 1 wherein using the switch to duplicate at least the duplicated subportion of the data unit includes partitioning content from a combined stream comprising a forwarded signal and a filtered signal. ### Claim 19 (depends on 1) The method of claim 1 wherein the forwarded signal differs from the filtered signal. ### Claim 20 (depends on 1) The method of claim 1 wherein using the switch to duplicate at least the subportion of the payload portion of a data unit within the stream of data units includes transcoding an underlying media format of the data unit to a different bit rate.