TRANSFERRING DOCSIS FRAMES USING A LABEL SWITCHING NETWORK

• US 20090016458A1
• Filed: 07/11/2007
• Published: 01/15/2009
• Est. Priority Date: 07/11/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Martini, Luca, Asati, Rajiv, Guichard, James Neil, Chapman, John
• Granted Patent: US 7,773,594 B2
• Time in Patent Office: Days
• US Class Current: 375/261
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 45/507 Label distribution
• CPC Class Codes: H04L 45/68 Pseudowire emulation, e.g. IETF WG PWE3
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6168 involving cable transmission, e.g. using a cable modem

Abstract

In one embodiment, label distribution sessions are established between a Modular Cable Modem Termination System (M-CMTS) core and one or more remote PHYs. The label distribution sessions facilitate association of labels with either Radio Frequency (RF) channels or groups of the RF channels that extend from the remote PHYs to one or more cable modems. The labels are then used to facilitate communications between the M-CMTS core and the remote PHYs over a MultiProtocol Label Switching (MPLS) network.

Claims

1. A Cable Modem Termination System (CMTS) comprising:

one or more processors; and

a memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to;

conduct a label distribution session with a remote PHYsical layer (PHY) device, the PHY device having established at least one data path over a cable network;

establish a label switched path with the PHY device for communicating with one or more cable modems; and

use the label distribution session to associate the label switched path with the data path.

2. The CMTS of claim 1 wherein the label switched path operates according to a Packet Stream Protocol (PSP) mode that designates different priorities for sessions associated with the label switched path.

3. The CMTS of claim 1 wherein the label switched path operates according to a DOCSIS Moving Pictures Experts Group (MPEG) Packet Transport (D-MPT) mode.

4. The CMTS of claim 1,

wherein the data path is established over at least one Quadrature Amplitude Modulation (QAM) channel;

and

the processors are further operable to exchange at least one Label Distribution Protocol (LDP) message during the label distribution session, the LDP message identifying capabilities of both the PHY device and the QAM channel.

5. The CMTS of claim 4 wherein the LDP message includes a Forwarding Equivalence Class (FEC) Type-Length-Value (TLV) field that identifies the capabilities of both the PHY device and the QAM channel.

6. The CMTS of claim 4 wherein the LDP message identifies a QAM channel frequency and a transmit power amount used for the QAM channel.

7. The CMTS of claim 4 wherein the LDP message identifies a modulation algorithm used by the PHY device to modulate downstream messages.

8. The CMTS of claim 4 wherein the LDP message indicates when the QAM channel is configured with a muted Radio Frequency (RF) output.

9. The CMTS of claim 1 wherein the processors are further operable to:

associate a label with the label switched path;

associate the PHY device with the label; and

associate a QAM channel established by the PHY device with the label.

10. The CMTS of claim 1 wherein the processors are further operable to encapsulate a payload with a MultiProtocol Label Switching (MPLS) header, the MPLS header containing a label that causes the PHY device to forward the payload over the data path associated with the label switched path.

11. The CMTS of claim 1 wherein the processors are further operable to:

receive an encapsulated payload from the PHY device; and

remove one or more MPLS headers encapsulating the payload before handing over the payload for further processing.

12. A system comprising:

means for conducting a label distribution session with a remote PHYsical layer (PHY) device, the PHY device having established at least one data path over a cable network;

means for establishing a label switched path with the PHY device for communicating with one or more cable modems; and

means for associating the label switched path with the data path.

13. The system of claim 12 wherein the label switched path is established over a Downstream External Physical Interface (DEPI) and the data path is established over Hybrid Fiber Coax (HFC) cabling.

14. The system of claim 12 wherein the label distribution session associates the data path with a distributed Internet Protocol (IP) flow established between the PHY device and a Cable Modem Termination System (CMTS).

15. The system of claim 12 wherein the data path is a Quadrature Amplitude Modulation (QAM) channel that couples the PHY device to the cable modems.

16. The CMTS of claim 15 wherein the label switched path comprises a pseudowire and the processors are further operable to:

identify a channel identifier value for the QAM channel; and

select a pseudowire label value for the pseudowire to numerically correspond with the identified channel identifier value.

17. The CMTS of claim 16 wherein the pseudowire label correlates one of a plurality of pseudowire sessions with the QAM channel.

18. A method comprising:

conducting a label distribution session with a remote PHYsical layer (PHY) device, the PHY device having established at least one data path over a cable network;

establishing a label switched path with the PHY device for communicating with one or more cable modems; and

using the label distribution session to associate the label switched path with the cable network data path.

19. The method of claim 18 wherein the label distribution session associates the data path with a distributed Internet Protocol (IP) flow established between the PHY device and a Cable Modem Termination System (CMTS).

20. The method of claim 18 further comprising establishing one or more layer two tunnels for the label switched path, the tunnels for transferring communications received from a data network.

21. An apparatus comprising:

a first interface for exchanging packetized communications over a packet switched network;

a second different interface for exchanging modulated signals with one or more cable modems; and

one or more processors to exchange at least one label mapping message over the packet switched network, the label mapping message associating a label switched path extending from the first interface with at least one channel extending from the second interface.

22. The apparatus of claim 21 further comprising a mapping table formatted with an entry that associates a label value for the label switched path with and a channel identifier for the channel.

23. The apparatus of claim 22 wherein the label value is selected to numerically correspond with the channel identifier.

24. The apparatus of claim 21 wherein the label switched path is established across a MultiProtocol Label Switching (MPLS) network.

25. The apparatus of claim 21 wherein the channel comprises a plurality of Internet Protocol (IP) flows distributed over at least one physical connection that couples the apparatus to the cable modem.