Ethernet encapsulation over optical transport network

• US 7,684,419 B2
• Filed: 04/19/2005
• Issued: 03/23/2010
• Est. Priority Date: 04/19/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Loprieno, Gilberto
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): PATEL, CHANDRAHAS B
• Application Number:
  US11/109,139
• Publication Number:
  US 20060233194A1
• Time in Patent Office: 1,799 Days
• Field of Search: 370/392, 370/389, 370/474, 370/401, 370/466, 370/349, 709/236
• US Class Current: 370/401
• CPC Class Codes: H04J 2203/0085 Support of Ethernet
• CPC Class Codes: H04J 3/1658 carrying packets or ATM cells; H04J3/1664 takes precedence for payloads with different packet types
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 2212/00 Encapsulation of packets

Abstract

A method and system for encapsulating a frame for transport over an optical transport network are disclosed. A method includes receiving a packet at a network device and encapsulating the packet. The packet is received from a network having a line frequency different than a payload frequency of the optical transport network and the encapsulated packet is configured for transport directly over the optical transport network without modification to compensate for the different frequencies.

Claims

1. A method for encapsulating a packet for transport over an optical transport network, the method comprising:

receiving a Gigabit Ethernet packet at a network device;

encapsulating said packet, said encapsulating comprising;

replacing a preamble and a start of frame delimiter in said received Ethernet packet with overhead comprising a field configured to identify a client signal fail and a channel ID, wherein said overhead comprises a fewer number of bytes than the number of bytes removed from said packet, wherein replacing comprises removing eight bytes and inserting four bytes into said packet; and

transporting said packet over the optical transport network;

whereby said packet is received from a network having a line frequency different than a payload frequency of the optical transport network and said encapsulated packet is configured for transport directly over the optical transport network without modification to compensate for the different frequencies.

2. The method of claim 1 wherein said overhead further comprises a field indicating if said packet is a user data frame or a command management frame.

3. The method of claim 1 wherein said Gigabit Ethernet packet is a 10 Gigabit Ethernet LAN packet and wherein said transported packet corresponds to a frame structure set forth in ITU G.709 standard.

4. The method of claim 1 wherein said overhead further comprises a PDU length indication field and a header error check.

5. The method of claim 1 further comprising removing interpacket gap from said received packet.

6. The method of claim 1 further comprising removing a frame check sequence field from said received packet.

7. The method of claim 1 wherein transporting said packet comprises mapping said packet into an OPU2 frame.

8. The method of claim 1 further comprising performing error detection and correction and alignment, and inserting idle packets.

9. The method of claim 1 wherein said overhead comprises a PBYTE field containing said client signal fail and said channel ID.

10. An apparatus comprising:

a processor,

a computer-readable storage medium that stores instructions for execution by the processor, the instructions, comprising;

code for reading a Gigabit Ethernet packet received at a network device;

code for encapsulating said packet, said encapsulation code comprising;

code for replacing a preamble and a start of frame delimiter in said received Ethernet packet with overhead comprising a field configured to identify a client signal fail and a channel ID, wherein said overhead comprises a fewer number of bytes than the number of bytes removed from said packet, wherein replacing comprises removing eight bytes and inserting four bytes into said packet; and

code for transmitting said packet over the optical transport network;

whereby said packet is received from a network having a line frequency different than a payload frequency of the optical transport network and said encapsulated packet is configured for transport directly over the optical transport network without modification to compensate for the different frequencies.

11. The computer-readable storage medium of claim 10 further comprising code for removing interpacket gap.

12. The computer-readable storage medium of claim 10 further comprising code for removing a frame check sequence field.

13. The computer-readable storage medium of claim 10 wherein said received packet is a 10 Gigabit Ethernet LAN packet and wherein said transported packet corresponds to a frame structure set forth in ITU G.709 standard.

14. The computer-readable storage medium of claim 10 wherein said overhead comprises four or less bytes.

15. Apparatus for encapsulating a packet for transport over an optical transport network, comprising:

means for receiving a Gigabit Ethernet packet at a network device;

means for encapsulating said packet, said encapsulating means comprising;

means for replacing a preamble and a start of frame delimiter in said received Ethernet packet with overhead comprising a field configured to identify a client signal fail and a channel ID, wherein said overhead comprises a fewer number of bytes than the number of bytes removed from said packet, wherein replacing comprises removing eight bytes and inserting four bytes into said packet; and

means for transporting said packet over the optical transport network;

whereby said packet is received from a network having a line frequency different than a payload frequency of the optical transport network and said encapsulated packet is configured for transport directly over the optical transport network without modification to compensate for the different frequencies.

16. The apparatus of claim 15 wherein said overhead comprises four or less bytes.

17. A method for mapping an Ethernet frame to an optical transport network, the method comprising:

receiving an Ethernet packet from a network operating at a first frequency;

removing a preamble field and a start of frame delimiter field from the Ethernet packet;

replacing said preamble field and said start of frame delimiter field with overhead in the packet, said overhead comprising a field configured to identify a client signal fail and a channel ID, wherein replacing comprises removing eight bytes and inserting four bytes into said packet; and

transporting the packet directly over the optical transport network operating at a second frequency different from said first frequency.

18. The method of claim 17 wherein said overhead comprises at least one length indication field, a PBYTE field, and a header error correction field.

19. The method of claim 17 wherein said overhead comprises four or fewer bytes.