Access Node Comprising VOIP Cards with Common IP/MAC Address

• US 20120014383A1
• Filed: 03/18/2009
• Published: 01/19/2012
• Est. Priority Date: 03/18/2009
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Grandi, Vittoriano, Risso, Luca, Geromel, Paola
• Granted Patent: US 8,989,175 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2517 using port numbers
• CPC Class Codes: H04L 65/1046 Call controllers; Call servers

Abstract

Disclosed are methods and arrangements in a VoIP access node for handling downstream and upstream RTP packets associated with an ongoing VoIP call. One common IP address can be assigned to the all of the RTP traffic of an access node instead of assigning one IP address per VoIP card, This may be done by identifying the destination VoIP card based on the destination UDP port number in a received RTP packet. The number of public IP addresses needed for VoIP service may be reduced without increasing the cost of the access node.

Claims

1. An access node configured to handle downstream RTP packets associated with an ongoing VoIP call, the access node comprising:

a controller card connectable to an IP network; and

a first and at least one additional VoIP card connectable to the controller card, wherein the first VoIP card is the destination of the RTP packets and is configured with at least one UDP port number, the VoIP cards are assigned a common IP address and a common MAC address for the RTP packets;

means for receiving an RTP packet from the IP network, the RTP packet comprising the common IP address as a destination IP address, the common MAC address as a destination MAC address and a destination UDP port number; and

means for identifying a destination VoIP card based only on the destination UDP port number.

2. The access node according to claim 1, wherein the controller card comprises an access gateway application operable to configure the first VoIP card with the destination UDP port number during the setup of the VoIP call.

3. The access node according to claim 1, wherein the means for receiving is operable to also forward the received RTP packet to all of the VoIP cards, and wherein the means for identifying is located on each of the VoIP cards, and is further operable to discard the received RTP packet when the destination UDP port number of the RTP packet does not correspond to a UDP port number configured on the VoIP card.

4. The access node according to claim 1, wherein the controller card is configured with a range of non overlapping UDP port numbers for each of the VoIP cards, and wherein the means for identifying is located in the controller card and is further operable to forward the received packet to the one of the VoIP cards corresponding to a range of non overlapping UDP port numbers comprising the destination UDP port number of the RTP packet.

5. An access node according to claim 1, wherein the common MAC address is a MAC address of the controller card.

6. An access node according to claim 1, wherein the common MAC address is a unique MAC address.

7. An access node according to claim 1, wherein the controller card is further operable to reply to all ARP request messages or ICMP messages received from the IP network.

8. An access node according to claim 1, further configured to handle upstream RTP packets associated with an ongoing VoIP call, wherein the first VoIP card is operable to generate an RTP packet comprising the common IP address as a source IP address and the common MAC address as a source MAC address, and to forward the generated RTP packet to the IP network.

9. An access node according to claim 8, wherein the generated RTP packet further comprises a destination MAC address configured on the first VoIP card during setup of the VoIP call.

10. An access node according to claim 8, wherein the generated RTP packet further comprises a destination MAC address provided by the controller card using ARP.

11. An access node according to claim 1, wherein the controller card is further operable to handle all ICMP messages towards the IP network.

12. A method in an access node for handling downstream RTP packets associated with an ongoing VoIP call, the access node comprising a controller card connected to an IP network, and a first and at least one additional VoIP card connected to the controller card, wherein the first VoIP card is a destination of the RTP packets, and is configured with at least one UDP port number, the method comprising:

assigning a common IP address and a common MAC address for the RTP packets to the VoIP cards;

receiving an RTP packet from the IP network, the RTP packet comprising the common IP address as a destination IP address, the common MAC address as a destination MAC address and a destination UDP port number; and

identifying a destination VoIP card based only on the destination UDP port number.

13. A method according to claim 12, wherein the first VoIP card is configured with the destination UDP port number during the setup of the VoIP call by an access gateway application on the controller card.

14. A method according to claim 12, wherein the receiving of the RTP packet also comprises forwarding the received RTP packet to all of the VoIP cards, and wherein the identifying of the destination VoIP card is performed by each of the VoIP cards by discarding the received RTP packet when the destination UDP port number of the RTP packet does not correspond to a UDP port number configured on the VoIP card.

15. A method according to claim 12, wherein the controller card is configured with a range of non overlapping UDP port numbers for each of the VoIP cards, and wherein the identifying of the destination VoIP card is performed by the controller card by forwarding the received RTP packet to a VoIP card corresponding to the range of non overlapping UDP port numbers comprising the destination UDP port number of the RTP packet.

16. A method according to claim 12, wherein the common MAC address is a MAC address of the controller card.

17. A method according to claim 12, wherein the common MAC address is a unique MAC address.

18. A method according to claim 12, wherein the controller card is operable to reply to all ARP request messages or ICMP messages received from the IP network.

19. A method in an access node for handling upstream RTP packets associated with an ongoing VoIP call, the access node comprising a controller card connected to an IP network, and a first and at least one additional VoIP card connected to the controller card, the first VoIP card being the origin of the RTP packets, and wherein the VoIP cards have been assigned a common IP address and a common MAC address for the RTP packets, the method comprising the following performed by the first VoIP card:

generating an RTP packet comprising the common IP address as a source IP address and the common MAC address as a source MAC address; and

forwarding the generated RTP packet to the IP network.

20. A method according to claim 19, wherein the common MAC address is a MAC address of the controller card.

21. A method according to claim 19, wherein the common MAC address is a unique MAC address.

22. A method according to claim 19, wherein the generated RTP packet further comprises a destination MAC address configured on the first VoIP card during setup of the VoIP call.

23. A method according to claim 19, wherein the generated RTP packet further comprises a destination MAC address provided by the controller card using ARP.

24. A method according to claim 19, wherein the controller card is operable to handle all ICMP messages towards the IP network.