Network path probing using available network connections

Patent metadata

Field	Value
Publication number	US-10158998-B2
Application number	US-201615187837-A
Country	US
Kind code	B2
Filing date	Jun 21, 2016
Priority date	Jun 21, 2016
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

Various embodiments provide methods, devices, and non-transitory processor-readable storage media enabling network path probing with a communications device by sending probes via a network connection to a STUN server and receiving probe replies. The communications device may increment a counter and transmit a test probe configured to be dropped at the first access point (NAT) causing all subsequent NATs to release their IP/port mappings. The communications device may send another probe to the STUN server and receive a probe reply. The communications device may compare the first and second probe replies to determine whether the final IP addresses within the network path match. By continuously incrementing the counter and querying access points, the communications device may determine the number of access points lay along any given network path. The presence of addition or unexpected numbers of NAT Servers may indicate the presence of a rogue access point.

First claim

What is claimed is:

1. A method of network probing by a communications device, comprising:
transmitting a first probe addressed to a Simple Traversal Utilities for NATs (STUN) server from the communications device via a network connection to a first Network Address Translator (NAT);
receiving, at the communications device, a first probe reply from the STUN server;
incrementing a probe timeout counter that indicates a number of NATs along a network traffic path that a probe will traverse before being dropped;
transmitting a first test probe including the incremented probe timeout counter in packet header information of the first test probe via the network connection, the first test probe causing each of the number of NATs indicated by the incremented probe timeout counter to maintain an active address translation mapping for the communications device;
transmitting a second probe addressed to the STUN server from the communications device via the network connection;
receiving, at the communications device, a second probe reply from the STUN server;
determining whether packet header information of the first probe reply matches packet header information of the second probe reply; and
determining that the number of NATs in the network traffic path is equal to the incremented probe timeout counter in response to determining that the packet header information of the first probe reply matches the packet header information of the second probe reply.

2. The method of claim 1 , wherein the first probe and the second probe each comprises a communications device Internet Protocol (IP) address, a communications device communications port number, a STUN server IP address, a STUN server communications port number, and a communication protocol used to transmit the probe.

3. The method of claim 1 , further comprising:
in response to determining that the packet header information of the first probe reply does not match the packet header information of the second probe reply
incrementing the incremented probe timeout counter to produce an updated probe timeout counter;
transmitting a second test probe including the updated probe timeout counter in packet header information of the second probe via the network connection, the second test probe causing each of the number of NATs indicated by the updated probe timeout counter to maintain an active address translation mapping for the communications device;
transmitting a third probe addressed to the STUN server from the communications device via the network connection;
receiving, at the communications device, a third probe reply from the STUN server;
determining whether packet header information of the third probe reply matches packet header information of the second probe reply; and
determining that the number of NATs in a network path is equal to the updated probe timeout counter in response to determining that the packet header information of the third probe reply matches the packet header information of the second probe reply.

4. The method of claim 1 , further comprising determining that a rogue access point is present in the network path in response to determining that the determined number of NATs in the network path does not match a predetermined number of NATs.

5. The method of claim 1 , wherein the packet header information of the first probe reply is a final IP address and port number, and the packet header information of the second probe reply is a second final IP address and port number.

6. The method of claim 1 , further comprising initializing the probe timeout counter to zero prior to transmitting the first probe.

7. The method of claim 1 , wherein IP addresses and local ports of multiple computing devices are mapped to the same global IP address and global port of the first NAT.

8. A communications device, comprising:
a transceiver configured to send and receive packets over a communications network; and
a processor coupled to the transceiver and configured to:
transmit a first probe addressed to a Simple Traversal Utilities for NATs (STUN) server via a network connection to a first Network Address Translator (NAT);
receive a first probe reply from the STUN server;
increment a probe timeout counter indicating that indicates a number of NATs along a network traffic path that a probe will traverse before being dropped;
transmit a first test probe including the incremented probe timeout counter in packet header information of the first test probe via the network connection, the first test probe causing each of the number of NATs indicated by the incremented probe timeout counter to maintain an active address translation mapping for the communications device;
transmit a second probe addressed to the STUN server via the network connection;
receive a second probe reply from the STUN server;
determine whether packet header information of the first probe reply matches packet header information of the second probe reply; and
determine that the number of NATs in a network path is equal to the incremented probe timeout counter in response to determining that the packet header information of the first probe reply matches the packet header information of the second probe reply.

9. The communications device of claim 8 , wherein the first probe and the second probe each comprises a communications device Internet Protocol (IP) address, a communications device communications port number, a STUN server IP address, a STUN server communications port number, and a communication protocol used to transmit the probe.

10. The communications device of claim 8 , wherein the processor is further configured with processor-executable instructions to:
in response to determining that the packet header information of the first probe reply does not match the packet header information of the second probe reply
increment the incremented probe timeout counter to produce an updated probe timeout counter;
transmit a second test probe including the updated probe timeout counter in packet header information of the second probe via the network connection, the second test probe causing each of the number of NATs indicated by the updated probe timeout counter to maintain an active address translation mapping for the communications device;
transmit a third probe addressed to the STUN server via the network connection;
receiving a third probe reply from the STUN server;
determine whether packet header information of the third probe reply matches packet header information of the second probe reply; and
determine that the number of NATs in a network path is equal to the updated probe timeout counter in response to determining that the packet header information of the third probe reply matches the packet header information of the second probe reply.

11. The communications device of claim 8 , wherein the processor is further configured with processor-executable instructions to determine that a rogue access point is present in the network path in response to determining that the determined number of NATs in the network path does not match a predetermined number of NATs.

12. The communications device of claim 8 , wherein the packet header information of the first probe reply is a final IP address and port number, and the packet header information of the second probe reply is a second final IP address and port number.

13. The communications device of claim 8 , wherein the processor is further configured with processor-executable instructions to initialize the probe timeout counter to zero prior to transmitting the first probe.

14. The communications device of claim 8 , wherein IP addresses and local ports of

Assignees

• Qualcomm Inc

Inventors

• Ahmadzadeh Seyed Ali
• Das Saumitra Mohan
• Gupta Rajarshi

Classifications

• H04L61/2503

  Translation of Internet protocol [IP] addresses · CPC title

• H04L61/2575

  using address mapping retrieval, e.g. simple traversal of user datagram protocol through session traversal utilities for NAT [STUN] · CPC title

• H04W48/16

  Discovering, processing access restriction or access information · CPC title

• H04L63/1425

  Traffic logging, e.g. anomaly detection · CPC title

• H04L43/10

  Active monitoring, e.g. heartbeat, ping or trace-route · CPC title