# US 2014/0156836 A1 · Cooperative proxy auto-discovery and connection interception > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0156836 A1 - Document ID: US20140156836A1 - Status: Published application - Kind: A1 - Application number: 14/172,459 - Filed: 2014-02-04 - Published: 2014-06-05 - Earliest claimed: 2003-08-12 - Assignees: Riverbed Technology, Inc. - Applicants: Riverbed Technology, Inc. - Inventors: Michael J. Demmer; Steven McCanne; Alfred Landrum - Web page: https://patentgrep.com/patent/US20140156836A1 ## CPC - H04W 4/02: Services making use of location information - H04L 43/04: Processing captured monitoring data, e.g. for logfile generation - H04L 43/12: Network monitoring probes - H04L 67/52: specially adapted for the location of the user terminal - H04L 67/535: {Tracking the activity of the user (network monitoring arrangements H04L43/00; recording of computer activity G06F11/34)} - H04W 4/20: Services signaling; Auxiliary data signalling, i.e. transmitting data via a non-traffic channel - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In a network supporting transactions between clients and servers and proxies that are interposable in a network path, a pair of proxies can modify a packet stream such that packet data from client to server is transformed at a client-side proxy of the pair and untransformed at a server-side of the pair and packet data from server to client is transformed at the server-side proxy and untransformed at the client-side proxy. A discovering proxy transparently discovers its position in a proxy pair by using proxy signals. A discovering proxy might determine that it is a client-side proxy by receipt of a packet from client without a proxy signal, or that it is a server-side proxy by receipt of a packet from server without a return proxy signal. Once a proxy pair is discovered, it might transform traffic from server to client or vice versa, transforming and untransforming the traffic. ## Claims ### Claim 1 A method of probing for devices on a network path, the method comprising: monitoring, at a first probe node in the network path, packets directed at a target client and apparently from a target server to detect packets containing return signals, wherein the return signal is an indication that the device at a second probe node has detected a previously sent presence signal as being a probing signal; upon determining that a return signal is responsive to a previously sent presence signal, storing information associated with the second probe node at the first probe node; and using the stored information in future communications between the target client and the target server. ### Claim 2 (depends on 1) The method of claim 1, wherein prior to said monitoring, the method further comprises: receiving at the first probe node, a first packet from the target client, wherein the first packet is directed at the target server; and generating a modified first packet by adding the presence signal to the first packet. ### Claim 3 (depends on 2) The method of claim 2, wherein the method further comprises forwarding the modified first packet toward the target server. ### Claim 4 (depends on 1) The method of claim 1, wherein storing information involves updating a mapping table that is in storage and that is accessible to the first probe node. ### Claim 5 A non-transitory computer-readable storage medium storing instructions that, when executed by a computer, cause the computer to perform a method of probing for devices on a network path, the method comprising: monitoring, at a first probe node in the network path, packets directed at a target client and apparently from a target server to detect packets containing return signals, wherein the return signal is an indication that the device at a second probe node has detected a previously sent presence signal as being a probing signal; upon determining that a return signal is responsive to a previously sent presence signal, storing information associated with the second probe node at the first probe node; and using the stored information in future communications between the target client and the target server. ### Claim 6 (depends on 5) The computer-readable storage medium of claim 5, wherein prior to said monitoring, the method further comprises: receiving at the first probe node, a first packet from the target client, wherein the first packet is directed at the target server; and generating a modified first packet by adding the presence signal to the first packet. ### Claim 7 (depends on 6) The computer-readable storage medium of claim 6, wherein the method further comprises forwarding the modified first packet toward the target server. ### Claim 8 (depends on 5) The computer-readable storage medium of claim 5, wherein storing information involves updating a mapping table that is in storage and that is accessible to the first probe node. ### Claim 9 An apparatus for probing for devices on a network path, the apparatus comprising: a processor; a monitoring mechanism configured to monitor, at a first probe node in the network path, packets directed at a target client and apparently from a target server to detect packets containing return signals, wherein the return signal is an indication that the device at a second probe node has detected a previously sent presence signal as being a probing signal; a storage mechanism configured to store information associated with the second probe node at the first probe node upon determining that a return signal is responsive to a previously sent presence signal; and a usage mechanism configured to use the stored information in future communications between the target client and the target server. ### Claim 10 (depends on 9) The apparatus of claim 9, further comprising: a receiving mechanism configured to receive, prior to the monitoring, at the first probe node, a first packet from the target client, wherein the first packet is directed at the target server; and a generating mechanism configured to generate, prior to the monitoring, a modified first packet by adding the presence signal to the first packet. ### Claim 11 (depends on 10) The apparatus of claim 10, further comprising a forwarding mechanism configured to forward the modified first packet toward the target server. ### Claim 12 (depends on 9) The apparatus of claim 9, further comprising a storing mechanism configured to store information by updating a mapping table that is in storage and that is accessible to the first probe node.