Method for ensuring VLAN integrity for voice over internet protocol telephones

• US 7,227,859 B1
• Filed: 04/17/2002
• Issued: 06/05/2007
• Est. Priority Date: 04/19/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: McCloghrie, Keith, Finn, Norman W., Habib, Ahsan, Testa, Stefano
• Primary Examiner(s): Pham; Chi
• Assistant Examiner(s): ABELSON, RONALD B
• Application Number:
  US10/125,208
• Time in Patent Office: 1,875 Days
• Field of Search: 370/352, 370/354, 370/389, 370/392, 370/396
• US Class Current: 370/354
• CPC Class Codes: H04L 12/4645 Details on frame tagging routing of packets H04L45/00; support for virtual LAN H04L49/354
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 47/2483 involving identification of individual flows
• CPC Class Codes: H04L 47/31 by tagging of packets, e.g. using discard eligibility [DE] bits
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/80 Responding to QoS

Abstract

A system and method for implementing telephony devices in a distributed network environment is disclosed. The present invention provides for checking data packets to ensure that non-voice data packets are properly tagged to be transmitted on a native virtual local area network (“VLAN”). Voice data packets transmitted on a separate VLAN with a higher priority.

Claims

1. A method for ensuring data packet tag integrity, the method comprising:

receiving a message in a first telephony device to check contents of incoming data packets;

checking the contents of the incoming data packets; and

re-marking the incoming data packets virtual local area network information with a tag for one of a plurality of virtual local area networks based on the contents of the incoming data packets in response to the message.

2. The method of claim 1 further comprising the first telephony device sending a second message to a second telephony device to check contents of incoming data packets to the second telephony device.

3. A method for ensuring information integrity within virtual local area networks, the method comprising:

maintaining a first identifier corresponding to a voice virtual local area network;

maintaining a second identifier corresponding to a data virtual local area network;

receiving a packet having the first identifier;

determining whether the packet encodes voice information;

if the packet does not encode voice information, changing the first identifier to the second identifier in the packet; and

communicating the packet.

4. The method of claim 3, further comprising:

receiving a second packet having the second identifier;

determining whether the second packet encodes voice information;

if the second packet encodes voice information, changing the second identifier to the first identifier in the second packet; and

communicating the second packet.

5. The method of claim 3, wherein the first identifier and the second identifier each comprise virtual local area network type-length value fields.

6. The method of claim 3, further comprising receiving a message from a remote device, the message indicating a first mode of operation.

7. The method of claim 6, further comprising forwarding the message to a second remote device.

8. The method of claim 6, wherein in the first mode of operation, the method comprises, for each of a plurality of received packets each having the first identifier:

determining whether the received packet encodes voice information;

if the received packet does not encode voice information, changing the first identifier to the second identifier in the received packet; and

communicating the packet.

9. An apparatus comprising:

a memory maintaining a first identifier corresponding to a voice virtual local area network and maintaining a second identifier corresponding to a data virtual local area network;

a first port operable to receive a packet having the first identifier;

a switching module operable to determine whether the packet encodes voice information and, if the packet does not encode voice information, to change the first identifier to the second identifier in the packet; and

a second port operable to communicate the packet.

10. The apparatus of claim 9, wherein:

the first port is further operable to receive a second packet having the second identifier;

the switching module is further operable to determine whether the second packet encodes voice information and, if the second packet encodes voice information, to change the second identifier to the first identifier in the second packet; and

the second port is further operable to communicate the second packet.

11. The apparatus of claim 9, wherein the first identifier and the second identifier each comprise virtual local area network type-length value fields.

12. The apparatus of claim 9, further operable to receive a message from a remote device using a selected one of the first port and the second port, the message indicating a first mode of operation.

13. The apparatus of claim 12, wherein in response to the message, the apparatus is operable to enter the first mode of operation, in the first mode of operation:

the first port operable to receive a plurality of packets each having the first identifier;

the switching module operable, for each of the received packets, to determine whether the packet encodes voice information and, if the packet does not encode voice information, to change the first identifier to the second identifier in the received packet.

14. The apparatus of claim 9, wherein the apparatus further comprises telephony communication circuitry operable to generate voice packets each having the first identifier and to communicate the voice packets using a selected one of the first port and the second port.

15. The apparatus of claim 9, wherein the apparatus comprises a network switch.

16. A system for ensuring data packet tag integrity, the system comprising:

a network switch operable to transmit a message to at least one telephony device controlling a mode of operation of the at least one telephony device; and

the at least one telephony device coupled to the network switch and operable in first and second modes of operation, and if the at least one telephony device is in the first mode of operation, the at least one telephony device is operable to;

check the contents of incoming data packets; and

re-mark the incoming data packets with one of a plurality of virtual local area network tags based on the contents of the incoming data packet in response to the message received from the network switch.

17. The system of claim 16, wherein the first mode of operation is an untrusted mode of operation and the second mode of operation is a trusted mode of operation.

18. The system of claim 16, wherein the at least one telephony device comprises a multiple port switch.

19. The system of claim 16, wherein the at least one telephony device comprises an access port, the access port used to transmit and receive data from an external network device connected to the access port.

20. The system of claim 19, wherein the external network device comprises one of:

a general purpose computer or a computer server.

21. The system of claim 16, wherein the at least one telephony device comprises an access port, the access port used to transmit and receive data from a second telephony device connected to the access port.

22. The system of claim 16, wherein the at least one telephony device comprises a network port, the network port used to transmit and receive data from the network switch.

23. The system of claim 16, wherein the at least one telephony device comprises an internal telephone port, the internal telephone port used to transmit and receive data from a telephone circuit internal to the at least one telephony device.

24. The system of claim 16, wherein one of a plurality of virtual local area networks is a native virtual local area network, the native virtual local area network communicating non-voice data packets.

25. The system of claim 16, wherein one of a plurality of virtual local area networks is a voice virtual local area network, the second virtual area network being a voice virtual local area network communicating voice data packets.