Cooperative proxy auto-discovery and connection interception

• US 9,172,620 B2
• Filed: 02/04/2014
• Issued: 10/27/2015
• Est. Priority Date: 08/12/2003
• Status: Expired due to Term

• Current Assignee: Riverbed Technology, LLC (Riverbed Technology Incorporated)
• Original Assignee: Riverbed Technology Incorporated
• Inventors: Demmer, Michael J., McCanne, Steven, Landrum, Alfred
• Primary Examiner(s): HOANG, HIEU T
• Application Number:
  US14/172,459
• Publication Number:
  US 20140156836A1
• Time in Patent Office: 630 Days
• Field of Search: 709/227, 709/228
• US Class Current: 1/1
• CPC Class Codes: H04L 43/04 Processing captured monitoring data, e.g. for logfile generation
• CPC Class Codes: H04L 43/12 Network monitoring probes
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04L 67/535 Tracking the activity of the user network monitoring arrangements H04L43/00; recording of computer activity G06F11/34
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/20 Services signaling; Auxiliary data signalling, i.e. transmitting data via a non-traffic channel

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

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, wherein storing information involves updating a mapping table that is in storage and that is accessible to the first probe node; and

using the stored information in future connections between the target client and the target server.

2. 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.

3. The method of claim 2, wherein the method further comprises forwarding the modified first packet toward the target server.

4. 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, wherein storing information involves updating a mapping table that is in storage and that is accessible to the first probe node; and

using the stored information in future connections between the target client and the target server.

5. The computer-readable storage medium of claim 4, 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.

6. The computer-readable storage medium of claim 5, wherein the method further comprises forwarding the modified first packet toward the target server.

7. An apparatus for probing for devices on a network path, the apparatus comprising:

a processor; and

a non-transitory storage medium storing instructions that, when executed by the processor, cause the apparatus to perform a set of operations 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, wherein storing information involves updating a mapping table that is in storage and that is accessible to the first probe node; and

using the stored information in future connections between the target client and the target server.

8. The apparatus of claim 7, wherein the set of operations further comprising:

receiving, 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

generating, prior to the monitoring, a modified first packet by adding the presence signal to the first packet.

9. The apparatus of claim 8, wherein the set of operations further comprising forwarding the modified first packet toward the target server.