DEVICE AND METHOD FOR INTERCONNECTING TWO SUBNETWORKS

• US 20150120897A1
• Filed: 05/17/2013
• Published: 04/30/2015
• Est. Priority Date: 05/22/2012
• Status: Active Grant

• Current Assignee: Sagemcom Broadband SAS (Sagemcom Holding SAS)
• Original Assignee: Sagemcom Broadband SAS (Sagemcom Holding SAS)
• Inventors: Colin, Stphane
• Granted Patent: US 11,683,275 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: H04L 12/2809 indicating that an appliance service is present in a home automation network monitoring functionality H04L43/0817; discovery or management thereof, e.g. service location protocol [SLP] or web services, H04L67/51
• CPC Class Codes: H04L 12/2832 Interconnection of the control functionalities between home networks single bridge functionality H04L12/4625
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 49/15 Interconnection of switching modules
• CPC Class Codes: H04L 49/309 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 61/2528 Translation at a proxy
• CPC Class Codes: H04L 61/2585 through application level gateway [ALG]
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04L 61/59 using proxies for addressing

Abstract

An interconnection device for interconnecting two sub-networks, on which UPnP devices are connected: determines actual IP addresses and port numbers of servers of the UPnP device; allocates a port number to each server, establishes a connection with a UPnP device of the femtocell and a connection with a UPnP device of the local area network; replaces, in frames received via one of said connections, each actual server IP address and port number allocated by the interconnection device to said server; and replaces, in frames received via one of said connections, each actual IP address and port number with an IP address of the interconnection device to said server; and replaces, in said received frames, each IP address of the interconnection device and port number allocated by the interconnection device to a server with the IP address and port number of the corresponding server.

Claims

1. An interconnection method for interconnecting first and second sub-networks, said first sub-network being a local network to which a gateway connecting said first sub-network to a third sub-network is connected, said first and second sub-networks being adapted for enabling UPnP devices to be connected thereto, each UPnP device comprising at least one server associated with an IP address and a port number, wherein an interconnection device interconnecting said first and second sub-networks performs:

determining, for said first and second sub-networks, actual IP addresses and port numbers of servers of UPnP devices;

allocating a port number to each one of said servers;

establishing, upon receiving a connection request corresponding to a port number allocated by the interconnection device to one said server, a connection between the interconnection device and said server, and a connection between the interconnection device and the UPnP device that sent said request;

and, in at least one frame, received by the interconnection device via one of said connections;

replacing in said frame, each actual IP address and port number of a server belonging to the sub-network where said frame was sent by an IP address of the interconnection device, usable for routing the data over the sub-network other than the one to which said server is connected among said first and second sub-networks, and the port number allocated by the interconnection device to said server; and

replacing, in said frame, each IP address of the interconnection device usable on the sub-network where the frame was sent and port number allocated by the interconnection device to a server by the IP address and the port number of the corresponding server.

2. The interconnection method according to claim 1, wherein the interconnection device determines the actual server IP addresses and port numbers, from UDP datagrams transmitted by said servers during a UPnP discovery phase and, for each said UDP datagram, the interconnection device performs:

replacing each actual IP address and port number of server belonging to the sub-network where said UDP datagram was sent with an IP address of the interconnection device, usable for routing the data over the sub-network other than the one to which said server is connected among said first and second sub-networks, and the port number allocated by the interconnection device to said server; and

replacing each IP address of the interconnection device usable on the sub-network where said UDP datagram was sent and port number allocated by the interconnection device to a server by the IP address and the port number of the corresponding server.

3. The interconnection method according to claim 2, wherein the interconnection device firstly subscribes, on each of the first and second sub-networks, to a predefined IP address and port number to which the multicast UDP datagrams transmitted during the UPnP discovery phase are sent, and listens out for UDP datagrams transmitted to said IP address of the interconnection device and the port number allocated by the interconnection device to said server.

4. The interconnection method according to claim 3, wherein, the second sub-network being a femtocell, the interconnection device subscribes, on each of the first and second sub-networks, to said predefined IP address and port number, when the interconnection device detects the presence of a UPnP mobile terminal in the femtocell.

5. The interconnection device according to claim 1, wherein the interconnection device determines the actual server IP addresses and port numbers, from HTTP frames transported by TCP frames received by the interconnection device via said connections.

6. The interconnection method according to claim 1, wherein the interconnection device performs:

checking whether the actual port number of a server is already allocated by the interconnection device to another server;

allocating to the server the same port number as said actual port number, in case of positive verification;

otherwise allocating another port number to the server.

7. The interconnection method according to claim 1, wherein the interconnection device analyses an HTTP header in the frames received by the interconnection device via one of said connections, and the interconnection device makes a frame modification only if the CONTENT-TYPE field of the HTTP header is of the text type.

8. The interconnection method according to claim 1, wherein the interconnection device analyses an HTTP header in the frames received by the interconnection device via one of said connections and, if the HOST field is present in the HTTP header, the interconnection device performs:

if the IP address contained in the HOST field is a server address, replacing said IP address with an IP address of the interconnection device, usable for routing the data over the sub-network other than the one to which said server is connected among said first and second sub-networks; and

if the IP address contained in the HOST field is an IP address of the interconnection device, replacing said IP address with the IP address of the server with which a said connection is established and which is connected to the sub-network other than the one from which said frames are received among the first and second sub-networks.

9. The interconnection method according to claim 1, wherein, after having established said connections, the interconnection device performs:

activating a timer having a predefined duration;

verifying whether at least one frame is received by the interconnection device via at least one of said connections; and

closing said connections when no frame has been received by the interconnection device via at least one of said connections before expiry of said timer.

10. The interconnection method according to claim 9, wherein the interconnection device also closes said connections when said interconnection device receives, via one of said connections, a connection closure request for said connection.

11. The interconnection method according to claim 1, wherein said second sub-network is a femtocell and the gateway is an Internet gateway.

16. A non-transitory computer-readable storage medium storing a computer program comprising instructions for implementing, by an interconnection device, the method according to claim 1, when said program is executed by a processor of the interconnection device.

12. An interconnection device intended to interconnect first and second sub-networks, said first sub-network being a local network to which a gateway connecting said first sub-network and a third sub-network is connected, said first and second sub-networks being adapted for enabling connecting UPnP devices thereto, each UPnP device comprising at least one server associated with an IP address and a port number wherein the interconnection device comprises:

means for determining, for said first and second sub-networks, actual IP addresses and port numbers of servers of UPnP devices;

means for allocating a port number to each one of said servers;

means for establishing, upon receiving a connection request corresponding to a port number allocated by the interconnection device to one said server, a connection between the interconnection device and said server, and a connection between the interconnection device and the UPnP device that sent said request;

means for receiving at least one frame via one of said connections; and

means for replacing in said frame each actual IP address and port number of server belonging to the sub-network where said frame was sent with an IP address of the interconnection device, usable for routing the data over the sub-network other than the one to which said server is connected among said first and second sub-networks, and the port number allocated by the interconnection device to said server; and

means for replacing in said frame each IP address of the interconnection device usable on the sub-network where the frame was sent and port number allocated by the interconnection device to a server by the IP address and the port number of the corresponding server.

13. The interconnection device according to claim 12, comprising:

a discovery assistant module adapted for analysing and modifying UDP datagrams transmitted by servers during a UPnP discovery phase; and

an address-translation module adapted for analysing and modifying HTTP frames transmitted by servers via said connections.

14. The interconnection device according to claim 12, wherein said second sub-network is a femtocell and said gateway is an Internet gateway.

17. The interconnection device according to claim 13, wherein said second sub-network is a femtocell and said gateway is an Internet gateway.

15. (canceled)