Transmission of digital information in a frame switched data network

• US 8,189,475 B2
• Filed: 10/25/2007
• Issued: 05/29/2012
• Est. Priority Date: 10/27/2006
• Status: Active Grant

• Current Assignee: Coriant Oy (Infinera Corp.)
• Original Assignee: Tellabs Oy (Infinera Corp.)
• Inventors: Laulainen, Mikko, Jekunen, Heikki
• Primary Examiner(s): Shah, Chirag
• Assistant Examiner(s): Patel, Jay P
• Application Number:
  US11/923,704
• Publication Number:
  US 20080273530A1
• Time in Patent Office: 1,678 Days
• Field of Search: 370/235, 370/471, 370/475, 370/476
• US Class Current: 370/235
• CPC Class Codes: H04L 12/407 with decentralised control

Abstract

The invention relates to transmitting digital information between the network elements of a frame switched data network. In the present invention, it has surprisingly been discovered that the padding bits of the data field of a minimum sized Ethernet frame can be used for transmitting digital information between the elements of a data network. In that case the frame data field (109) of a minimum sized Ethernet frame contains an information unit (DIU), the size of which in bytes is smaller than the minimum size of a frame data field, as well as other digital information (DI) that is written in an area (107) of the frame data field that corresponds to the padding bits. The invention makes it possible to also utilize the data transmission capacity needed for transmitting the padding bits.

Claims

1. A system for transmitting digital information from a first network element to a second network element in an Ethernet frame switched data network, the system including:

in said first network element a writing unit that defines which bits of a frame data field of a minimum sized Ethernet frame correspond to padding bits in a frame data field of said minimum sized Ethernet frame on the basis of a type of an information unit placed in said frame data field and on the basis of a predetermined rule and to write said digital information into a first portion of the padding bits, and

in said second network element a reading unit that reads said digital information from said padding bits,

wherein said writing unit writes flag data into a second portion of the padding bits of said frame data field of said minimum sized Ethernet frame, said flag data indicates whether said first portion of the padding bits represent said digital information.

2. The system according to claim 1, wherein said writing unit writes said digital information in said first portion of the padding bits during transmission of said minimum sized Ethernet frame from said first network element, and said reading unit reads said digital information from said first portion of the padding bits during reception of said minimum sized Ethernet frame in said second network element.

3. The system according to claim 2, wherein said digital information represents time stamp information that indicates a transmission moment of said minimum sized Ethernet frame from said first network element.

4. The system according to claim 1, wherein said digital information represents time stamp information that indicates a transmission moment of said minimum sized Ethernet frame from said first network element.

5. The system according to claim 1, wherein said digital information represents operation control information of said Ethernet frame switched data network.

6. The system according to claim 1, wherein said digital information represents management information of said Ethernet frame switched data network.

7. The system according to claim 1, wherein the information unit located in said frame data field is an IP-packet that contains data indicating the size of said IP-packet (Internet Protocol).

8. The system according to claim 1, wherein said information unit placed in the frame data field is an SSM-message, and that said predetermined rule is represented by a known size of the SSM-message (Synchronization Status Messaging in synchronous Ethernet).

9. The system according to claim 1, wherein said writing unit divides a digital information entity into at least two parts, each of said parts representing the digital information to be written into the first portion of the padding bits of a frame data field of one minimum sized Ethernet frame.

10. The system according to claim 9, wherein said reading unit compiles said digital information entity of at least two parts, each of said parts representing the digital information read from the first portion of the padding bits of a frame data field of one minimum sized Ethernet frame.

11. A network element, comprising:

a writing unit, wherein said writing unit defines which bits of a frame data field of a first minimum sized Ethernet Frame correspond to padding bits in the frame data field of the first minimum sized Ethernet frame on the basis of a type of an information unit placed in said frame data field and on the basis of a predetermined rule,

writes digital information to be transmitted into a first portion of the padding bits of the frame data field of the first minimum sized Ethernet frame, and

writes flag data into a second portion of the padding bits of said frame data field of said first minimum sized Ethernet frame, said flag data being indicates whether said first portion of the padding bits represent said digital information,

wherein the network element further comprises a reading unit that reads received digital information from a first portion of padding bits of a frame data field of a second minimum sized Ethernet frame during reception of the second minimum sized Ethernet frame in said network element.

12. The network element according to claim 11, wherein said writing unit writes said digital information to be transmitted in the first portion of the padding bits of the frame data field of said first minimum sized Ethernet frame during transmission of said first minimum sized Ethernet frame from said network element.

13. The network element according to claim 12, wherein said digital information to be transmitted represents time stamp information that indicates a transmission moment of said first minimum sized Ethernet frame from said network element.

14. The network element according to claim 11, wherein the network element is an IP router (Internet Protocol).

15. The network element according to claim 11, wherein the network element is an Ethernet switch.

16. The network element according to claim 11, wherein the network element is a mobile phone network base station.

17. A method for transmitting digital information from a first network element to a second network element in an Ethernet frame switched data network, the method comprising:

in said first network element, defining which bits of a frame data field of a minimum sized Ethernet frame correspond to padding bits in a frame data field of said minimum sized Ethernet frame on the basis of a type of an information unit placed in said frame data field and on the basis of a predetermined rule,

in said first network element, writing said digital information into a first portion of the padding bits of the frame data field of the minimum sized Ethernet frame,

the frame data field containing a digital information unit in addition to the padding bits

in said first network element, writing flag data into a second portion of the padding bits of said frame data field of said minimum sized Ethernet frame, said flag data indicates whether said first portion of the padding bits represent said digital information,

transmitting said minimum sized Ethernet frame from said first network element to said second network element, and

reading said digital information from said first portion of the padding bits in said second network element.

18. The method according to claim 17, wherein said digital information is written in said first portion of the padding bits during transmission of said minimum sized Ethernet frame from said first network element, and that said digital information is read from said first portion of the padding bits during reception of said minimum sized Ethernet frame in said second network element.

19. The method according to claim 18, wherein said digital information represents time stamp information that indicates a transmission moment of said minimum sized Ethernet frame from said first network element.

20. The method according to claim 17, wherein said digital information represents time stamp information that indicates a transmission moment of said minimum sized Ethernet frame from said first network element.

21. The method according to claim 17, wherein said digital information represents operation control information of said Ethernet frame switched data network.

22. The method according to claim 17, wherein digital information represents management information of said Ethernet frame switched data network.

23. The method according to claim 17, wherein said information unit placed in the frame data field is an IP-packet that contains data indicating the size of said IP-packet (Internet Protocol).

24. The method according to claim 17, wherein the information unit placed in the frame data field is an SSM-message, and that the applied predetermined rule is data indicating a size of the SSM-message (Synchronization Status Messaging in synchronous Ethernet).

25. The method according to claim 17, wherein a digital information entity is divided in said first network element into at least two parts, each of said parts representing digital information to be written into the first portion of the padding bits of a frame data field of one minimum sized Ethernet frame.

26. The method according to claim 25, wherein said digital information entity is compiled in said second network element of at least two parts, each of said parts representing digital information read from the first portion of padding bits of a frame data field of one minimum sized Ethernet frame.