SYSTEMS AND METHODS FOR HANDLING PACKET FRAGMENTATION

• US 20110142070A1
• Filed: 02/18/2011
• Published: 06/16/2011
• Est. Priority Date: 03/22/2002
• Status: Abandoned Application

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: LIM, Raymond Marcelino Manese, Libby, Jeffrey G.
• Application Number:
  US13/030,852
• Publication Number:
  US 20110142070A1
• Time in Patent Office: Days
• US Class Current: 370/470
• CPC Class Codes: H04L 45/60 Router architectures
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/36 by determining packet size, e.g. maximum transfer unit [MTU]
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/3072 Packet splitting
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/166 IP fragmentation; TCP segmentation

Abstract

A packet header processing engine receives a header of a packet. The received header includes a size of the packet. A maximum transfer unit size of a destination interface of the packet may be determined. The packet header processing engine determines whether the size of the packet exceeds the maximum transfer unit size of the destination interface. If the size of the packet does not exceed the maximum transfer unit size of the destination interface, the packet header processing engine generates a new header from the received header. If the size of the packet exceeds the maximum transfer unit size of the destination interface, the packet header processing engine generates a fragment header from the received header. The packet header processing engine may recycle the fragment header for further processing in addition to forming a first fragment packet from the fragment header.

Claims

1-21. -21. (canceled)

22. A device, comprising:

one or more memory units to store a plurality of instructions; and

one or more processors to execute instructions in the one or more memory units to;

receive a header of a packet, the header including a size of the packet and a maximum transfer unit size of a destination interface of the packet, and

generate a first fragment header from the received header if the size of the packet exceeds the maximum transfer unit size of the destination interface, where the first fragment header includes information indicating that the packet has been fragmented.

23. The device of claim 22, where the one or more processors are further to execute instructions to:

determine whether the size of the packet exceeds the maximum transfer unit size of the destination interface.

24. The device of claim 23, where the one or more processors are further to execute instructions to:

generate a new header from the received header if the size of the packet does not exceed the maximum transfer unit size of the destination interface.

25. The device of claim 24, where the one or more processors are further to execute instructions to:

form a packet including the new header.

26. The device of claim 22, where the first fragment header indicates a size of a remaining portion of the packet that exceeds the maximum transfer unit size of the destination interface.

27. The device of claim 26, where the one or more processors are further to execute instructions to:

form a first fragment packet including the first fragment header if the size of the remaining portion of the packet does not exceed the maximum transfer unit size of the destination interface.

28. The device of claim 22, where the first fragment header includes information from which a size of a remaining portion of the packet may be determined.

29. A network device, comprising:

an input component to receive packets, where the packets include header data and payload data;

a buffer, connected to the input component, to store the packets;

a descriptor reader component, connected to the input component, to receive the header data for the packets stored in the buffer and to perform lookups of descriptor information relating to the received packet header data from the input component; and

a packet header processing component, connected to the descriptor reader component, to;

construct a packet header from the packet header data and the descriptor information from the descriptor reader component,

send the packet header to the input component when a size of an associated packet exceeds a maximum transfer unit size of a destination interface of the associated packet, and

send the packet header to an output component when the size of the associated packet does not exceed the maximum transfer unit size of the destination interface of the associated packet.

30. The network device of claim 29, where the output component is coupled to the buffer and the packet header processing component, and where the output component is to construct a packet from the packet header constructed by the packet header processing component and from the payload data stored in the buffer.

31. The network device of claim 29, where the packet header data includes the size of the associated packet and the maximum transfer unit size of a destination interface for the associated packet.

32. The network device of claim 29, where the packet header processing component is further to:

determine whether the size of the packet exceeds the maximum transfer unit size of the destination interface for the packet.

33. The network device of claim 29, where the packet header includes a size of packet data, associated with the packet, to be read from the buffer.

34. A method performed by a network device, the method comprising:

receiving, by the network device, a header of a packet, the received header including a size of the packet;

determining, by the network device, whether the size of the packet exceeds a maximum transfer unit size of a destination interface for the packet; and

generating, by the network device, a first fragment header from the received header if the size of the packet exceeds the maximum transfer unit size of the destination interface.

35. The method of claim 34, further comprising:

forming a first fragment packet including the first fragment header;

processing the first fragment header, to identify information about a size of a remaining portion of the packet; and

determining whether the size of the remaining portion of the packet exceeds the maximum transfer unit size of the destination interface.

36. The method of claim 34, further comprising:

generating a new header from the received header if the size of the packet does not exceed the maximum transfer unit size of the destination interface.

37. The method of claim 36, further comprising:

forming a packet including the new header.

38. The method of claim 34, where the first fragment header includes the size of a remaining portion of the packet.

39. The method of claim 34, where the first fragment header includes information indicating that the packet has been fragmented.

40. The method of claim 34, where the received header includes the maximum transfer unit size of the destination interface.

41. The method of claim 34, further comprising:

generating a new header from the first fragment header if the size of the remaining portion of the packet does not exceed the maximum transfer unit size of the destination interface; and

forming a second fragment packet including the new header.

42. The method of claim 34, further comprising:

performing a lookup of descriptor information relating to the received packet header data to determine