METHOD FOR CONTROLLING THE TRAFFIC WITHIN A NETWORK STRUCTURE AND A NETWORK STRUCTURE

• US 20120182940A1
• Filed: 08/20/2010
• Published: 07/19/2012
• Est. Priority Date: 08/20/2009
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Europe Ltd (NEC Corporation)
• Inventors: Taleb, Tarik, Schmid, Stefan
• Granted Patent: US 8,787,380 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 8/082 for traffic bypassing of mobility servers, e.g. location registers, home PLMNs or home agents

Abstract

A reliable and flexible method for controlling traffic within a network structure without the addition of remarkable complexity to the core network is provided, the structure including a PDN (Packet Data Network), an operator core network with a DNS (Domain Name System) server, a HeNB (Home evolved Node B) or HNB (Home Node B) and/or eNB (Evolved Node B) or NB (Node B) and a UE (User Equipment) that is associated with the HeNB or HNB and/or eNB or NB. On the basis of a predefinable routing policy the DNS server is controlling whether a traffic from a UE to a destination address within a local network associated to the HeNB or HNB or eNB or NB or within a PDN and/or vice versa will be routed via the core network or directly via the local network in support of local network protocol access or selected network protocol traffic offload.

Claims

1. A method for controlling the traffic within a network structure, said structure comprising a PDN (Packet Data Network), an operator core network with a DNS (Domain Name System) server, a HeNB (Home evolved Node B) or HNB (Home Node B) and/or eNB (Evolved Node B) or NB (Node B) and a UE (User Equipment) that is associated with said HeNB or HNB and/or eNB or NB,

characterized in that on the basis of a predefinable routing policy said DNS server is controlling whether a traffic from a UE to a destination address within a local network associated to the HeNB or HNB or eNB or NB or within a PDN and/or vice versa will be routed via the core network or directly via the local network in support of local network protocol access or selected network protocol traffic offload.

2. A method according to claim 1, wherein the PDN is the Internet, the network protocol is IP, the local network protocol access is LIPA (Local IP (Internet Protocol) Access) and the selected network protocol traffic offload is SIPTO (Selected IP Traffic Offload).

3. A method according to claim 1, wherein said DNS server indicates—

upon a DNS request by the UE—

in a DNS response a routing information with regard to the traffic routing via the core network or directly via the local network for local network protocol access or via a local traffic offload node nearby the Radio Access Network—

RAN for the selected network protocol traffic offload.

4. A method according to claim 1, wherein a LP-GW (Local PDN Gateway or L-GW) is associated to or collocated with the HeNB or HNB or eNB or NB.

5. A method according to claim 4, wherein said LP-GW is a LGGSN (Local GGSN) and is associated to or collocated with a HNB or NB.

6. A method according to claim 1, wherein a DNS proxy functionality is implemented at the LP-GW or at the HeNB or HNB or eNB or NB.

7. A method according to claim 3, wherein the routing information is provided by a flag in the DNS response, that indicates to the HeNB or HNB or eNB or NB or to a LP-GW the subsequent traffic routing.

8. A method according to claim 3, wherein a DNS proxy functionality is implemented at the HeNB or HNB or eNB or NB or at a LP-GW and provides a DestNAT (Destination Network Address Translation) network protocol address to the UE as part of the DNS response and to establish the binding/association between the DestNAT and the destination address within the local network or within the PDN.

9. A method according to claim 4, wherein the DNS server requests the LP-GW for a NAT for the destination address within the local network or within the PDN, if there is no DNS proxy functionality at the LP-GW.

10. A method according to claim 1, wherein the HeNB or eNB or a LP-GW has a Twice-NAT functionality for translating the addresses of both source and destination into two different addresses, a SrcNAT (Source Network Address Translation) address and DestNAT address, respectively.

11. A method according to claim 8, wherein a stateless Twice-NATing will be performed, if the DestNAT address includes the destination address within the local network or within the PDN.

12. A method according to claim 1, wherein—

without the involvement of LP-GW or HeNB or HNB or eNB or NB—

the DNS server directly provides the DestNAT address of the LP-GW or HeNB or HNB or eNB or NB, which is obtained by the DNS server from the LP-GW or HeNB or HNB or eNB or NB via some other means.

13. A method according to claim 1, wherein the HeNB or HNB or eNB or NB or an LP-GW supports a tunneling mechanism to a P-GW (PDN-Gateway) or S-GW (Serving Gateway) of the core network.

14. A method according to claim 13, wherein the P-GW is a GGSN and the S-GW is a SGSN.

15. A method according to claim 1, wherein the HeNB or HNB or eNB or NB or an LP-GW supports a tunneling mechanism to the UE.

16. A method according to claim 13, wherein a network layer of the UE maintains a per-connection or flow state to decide whether a traffic should be tunneled or not.

17. A method according to claim 13, wherein the UE supports a source routing mechanism.

18. A method according to claim 13, wherein two addresses are indicated in the DNS response, the address of the LP-GW or a local GW, routable within the core network, and the destination address within the local network or within the PDN.

19. A method according to claim 1, wherein said DNS server selects and indicates—

upon a DNS request by the UE—

in a DNS response to the UE which APN to use for a particular traffic or flow or connection, if the UE has or supports multiple PDP (Packet Data Protocol) context/PDN connections with different APNs.

20. A method according to claim 19, wherein at least one PDP context/PDN connection is dedicated for LIPA and/or SIPTO.

21. A method according to claim 19, wherein the DNS server has prior knowledge on available APNs or PDP contexts/PDN connections.

22. A method according to claim 19, wherein the UE notifies APNs currently available to UE in the prior DNS request.

23. A method according to claim 22, wherein the DNS server bases its APN selection on parameters or metrics that prioritize the available APN or APNs.

24. A method according to claim 19, wherein the UE—

preferably due to an indication or flag in a DNS response—

does not cache results of DNS responses subject to local network protocol access and/or selected network protocol traffic offload and preferably fully disables DNS caching for respective APNs.

25. A method according to claim 19, wherein the UE is involved in the final selection process of the APN or PDP context/PDN connection to be used for the traffic routing.

26. A network structure, preferably for carrying out the method according to claim 1, said structure comprising a PDN (Packet Data Network), an operator core network with a DNS (Domain Name System) server, a HeNB (Home evolved Node B) or HNB (Home Node B) and/or eNB (Evolved Node B) or NB (Node B) and a UE (User Equipment) that is associated with said HeNB or HNB and/or eNB or NB,

characterized in that the DNS server is configured in a way that on the basis of a predefinable routing policy said DNS server is controlling whether a traffic from a UE to a destination address within a local network associated to the HeNB or HNB or eNB or NB or within a PDN and/or vice versa will be routed via the core network or directly via a local network in support of local access protocol access or a selected network protocol traffic offload.