Determining the service set identification of an access point in a wireless local area network

• US 7,836,166 B2
• Filed: 06/28/2004
• Issued: 11/16/2010
• Est. Priority Date: 04/08/2002
• Status: Expired due to Fees

• Current Assignee: NetScout Systems Incorporated
• Original Assignee: Airmagnet (NetScout Systems Incorporated)
• Inventors: Kuan, Chia-Chee, Wu, Miles, Au, Dean
• Primary Examiner(s): Nguyen; Thu Ha T
• Application Number:
  US10/880,222
• Publication Number:
  US 20040236851A1
• Time in Patent Office: 2,332 Days
• Field of Search: 709223-224, 709/225, 370/338, 370/329, 370/252, 370/270, 455/432, 455/446
• US Class Current: 709/224
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/0847 Transmission error
• CPC Class Codes: H04L 43/12 Network monitoring probes
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 63/1408 by monitoring network traffic monitoring network traffic per se H04L43/00
• CPC Class Codes: H04L 63/162 at the data link layer
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 8/22 Processing or transfer of terminal data, e.g. status or physical capabilities
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The service set identification (SSID) of an access point (AP) in a wireless local area network (WLAN), where the AP suppresses its SSID in beacon frames broadcasted by the AP, is determined. At a detector located in the WLAN, a probe request broadcasted by a station through the WLAN is received. At the detector, a probe response sent by the AP to the station through the WLAN in response to the probe request broadcasted by the station is received. At the detector, the SSID of the AP is obtained from the received probe response.

Claims

1. A method to perform at a detector located in a wireless local area network (WLAN) to determine a service set identification (SSID) of an access point (AP) in the WLAN, wherein the AP suppresses a SSID in beacon frames broadcasted by the AP, the method comprising:

receiving, at the detector, a beacon frame sent by the AP;

determining from the beacon frame that the SSID of the AP has been suppressed;

if the SSID of the AP has been suppressed and the SSID cannot be obtained from the beacon frame,

receiving, at the detector, a probe request sent by a station through the WLAN to the AP that suppresses the SSID in the beacon frames;

receiving, at the detector, a probe response sent by the AP to the station through the WLAN in response to the probe request sent by the station;

determining, at the detector, the SSID of the AP from the received probe request that has been sent by the station to the AP, which sent the probe response; and

obtaining, at the detector, the SSID of the AP from the received probe response.

2. The method of claim 1, wherein the station and AP are all in the same basic service set (BSS).

3. The method of claim 2, wherein the detector, station and AP operate in accordance with the IEEE 802.11 standard.

4. The method of claim 1, further comprising:

at the detector, scanning a plurality of channels used in the WLAN to receive the probe request and the probe response.

5. The method of claim 1, further comprising:

at the detector, scanning one or more specified channels to receive the probe request and the probe response.

6. The method of claim 1, further comprising:

associating the SSID with the AP that sent the probe response.

7. A non-transitory computer-readable storage medium containing computer executable code to determine a service set identification (SSID) of an access point (AP) in a wireless local area network (WLAN), wherein the AP suppresses the SSID in beacon frames broadcasted by the AP, the computer executable code instructing a computer to operate as follows:

receiving, at a detector, a beacon frame sent by the AP;

determining from the beacon frame that the SSID of the AP has been suppressed;

if the SSID of the AP has been suppressed and the SSID cannot be obtained from the beacon frame,

receiving, at the detector, a probe request sent by a station through the WLAN to the AP that suppresses the SSID in the beacon frames;

receiving, at the detector, a probe response sent by the AP to the station through the WLAN in response to the probe request sent by the station;

determining, at the detector in the WLAN the SSID of the AP from the received probe request that has been sent by the station to the AP, which sent the probe response; and

obtaining, at the detector, the SSID of the AP from the received probe response.

8. The non-transitory computer-readable storage medium of claim 7, wherein the station and AP are all in the same basic service set (BSS).

9. The non-transitory computer-readable storage medium of claim 8, wherein the detector, station and AP operate in accordance with the IEEE 802.11 standard.

10. The non-transitory computer-readable storage medium of claim 7, further comprising:

at the detector, scanning a plurality of channels used in the WLAN to receive the probe request and the probe response.

11. The non-transitory computer-readable storage medium of claim 7, further comprising:

at the detector, scanning one or more specified channels to receive the probe request and the probe response.

12. The non-transitory computer-readable storage medium of claim 7, further comprising:

associating the SSID with the AP that sent the probe response.

13. A system to determine a service set identification (SSID) of an access point (AP) in a wireless local area network (WLAN), wherein the AP suppresses the SSID in beacon frames broadcasted by the AP, the system comprising:

a station located in the WLAN, wherein the station sends a probe request having a SSID through the WLAN to the AP that suppresses the SSID in the beacon frames; and

a detector located in the WLAN, wherein the detector is configured to;

receive a beacon frame sent by the AP;

determine from the beacon frame that the SSID of the AP has been suppressed; and

if the SSID of the AP has been suppressed and the SSID cannot be obtained from the beacon frame receive the probe request sent by the station;

receive a probe response sent by the AP to the station through the WLAN in response to the probe request sent by the station; and

determine that the SSID of the AP from the received probe request that has been sent by the station is the SSID of the AP, which sent the probe response; and

obtain, at the detector, the SSID of the AP from the received probe response.

14. The system of claim 13, wherein the station and AP are all in the same basic service set (BSS).

15. The system of claim 14, wherein the detector, station and AP operate in accordance with the IEEE 802.11 standard.

16. The system of claim 13, wherein the detector is configured to scan a plurality of channels used in the WLAN to receive the probe request and the probe response.

17. The system of claim 13, wherein the detector is configured to scan one or more specified channels to receive the probe request and the probe response.

18. The system of claim 13, wherein the detector is configured to associate the SSID with the AP that sent the probe response.