TRANSMISSION OF DIGITAL INFORMATION IN A FRAME SWITCHED DATA NETWORK

• US 20080273530A1
• Filed: 10/25/2007
• Published: 11/06/2008
• 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
• Granted Patent: US 8,189,475 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• 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 is arranged to write said digital information into first padding bits of a frame data field of a minimum sized Ethernet frame, and

in said second network element a reading unit that is arranged to read said digital information from said padding bits,

wherein said writing unit is arranged to write flag data into second padding bits of said frame data field of said minimum sized Ethernet frame, said flag data being arranged to indicate whether said first padding bits represent said digital information.

2. A system according to claim 1, wherein said writing unit is arranged to write said digital information in said first padding bits essentially during transmission of said minimum sized Ethernet frame from said first network element, and said reading unit is arranged to read said digital information from said first padding bits essentially during reception of said minimum sized Ethernet frame in said second network element.

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

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

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

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

7. A system according to claim 1, wherein said writing unit is arranged to define the share corresponding to padding bits in said frame data field on the basis of contents of an information unit located in said frame data field

8. A system according to claim 7, 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).

9. A system according to claim 1, wherein said writing unit is arranged to define the share corresponding to padding bits in said frame data field on the basis of a type of an information unit placed in said frame data field and on the basis of a predetermined rule.

10. A system according to claim 9, 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).

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

12. A system according to claim 11, wherein said reading unit is arranged to compile said digital information entity of at least two parts, each of said parts representing the digital information read from first padding bits of a frame data field of one minimum sized Ethernet frame.

13. A network element including a writing unit that is arranged to write digital information to be transmitted into first padding bits of a frame data field of a first minimum sized Ethernet frame, wherein said writing unit is arranged to write flag data into second padding bits of said frame data field of said minimum sized Ethernet frame, said flag data being arranged to indicate whether said first padding bits represent said digital information.

14. A network element according to claim 13, wherein the network element includes a reading unit that is arranged to read received digital information from first padding bits of a frame data field of a second minimum sized Ethernet frame.

15. A network element according to claim 13, wherein said writing unit is arranged to write said digital information to be transmitted in the first padding bits of the frame data field of said first minimum sized Ethernet frame essentially during transmission of said first minimum sized Ethernet frame from said network element.

16. A network element according to claim 14, wherein said reading unit is arranged to read said received digital information from the first padding bits of the frame data field of said second minimum sized Ethernet frame essentially during reception of the second minimum sized Ethernet frame in said network element.

17. A network element according to claim 15, wherein said digital information to be transmitted represents time stamp information that essentially indicates a transmission moment of said first minimum sized Ethernet frame from said network element.

18. A network element according to claim 13, wherein the network element is an IP router (Internet Protocol).

19. A network element according to claim 13, wherein the network element is an Ethernet switch.

20. A network element according to claim 13, wherein the network element is a mobile phone network base station.

21. 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, writing said digital information into first padding bits of a frame data field of a minimum sized Ethernet frame,

in said first network element, writing flag data into second padding bits of said frame data field of said minimum sized Ethernet frame, said flag data being arranged to indicate whether said first 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 padding bits in said second network element.

22. A method according to claim 21, wherein said digital information is written in said first padding bits essentially during transmission of said minimum sized Ethernet frame from said first network element, and that said digital information is read from said first padding bits essentially during reception of said minimum sized Ethernet frame in said second network element.

23. A method according to claim 21, wherein said digital information represents time stamp information that essentially indicates a transmission moment of said minimum sized Ethernet frame from said first network element.

24. A method according to claim 22, wherein said digital information represents time stamp information that essentially indicates a transmission moment of said minimum sized Ethernet frame from said first network element.

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

26. A method according to claim 21, wherein digital information represents management information of said Ethernet frame switched data network.

27. A method according to claim 21, wherein the share of the frame data field corresponding to padding bits is defined on the basis of contents of an information unit placed in said frame data field.

28. A method according to claim 27, 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).

29. A method according to claim 21, wherein the share of the frame data field corresponding to padding bits is defined on the basis of a type of an information unit placed in said frame data field and on the basis of a predetermined rule.

30. A method according to claim 29, 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).

31. A method according to claim 21, 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 first padding bits of a frame data field of one minimum sized Ethernet frame.

32. A method according to claim 31, 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 first padding bits of a frame data field of one minimum sized Ethernet frame.