Separation of data and control in a switching device

• US 8,681,796 B2
• Filed: 05/07/2012
• Issued: 03/25/2014
• Est. Priority Date: 12/16/1996
• Status: Expired due to Fees

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Sindhu, Pradeep S., Kompella, Kireeti, Ferguson, Dennis C., Liencres, Bjorn O., Agarwal, Nalini, Ju, Hann-Hwan, Lim, Raymond Marcelino Manese, Oskouy, Rasoul Mirzazadeh, Veeragandham, Sreeram
• Primary Examiner(s): HO, DUC CHI
• Application Number:
  US13/465,566
• Publication Number:
  US 20120219001A1
• Time in Patent Office: 687 Days
• Field of Search: 370/413, 370/401, 370/392, 370/389
• US Class Current: 370/392
• CPC Class Codes: G06F 15/167 using a common memory, e.g. mailbox
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/5652 Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly
• CPC Class Codes: H04L 2012/5679 Arbitration or scheduling
• CPC Class Codes: H04L 2012/5681 Buffer or queue management
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/72 Routing based on the source address
• CPC Class Codes: H04L 45/74591 using content-addressable memories [CAM]
• CPC Class Codes: H04L 47/6225 Fixed service order, e.g. Round Robin
• CPC Class Codes: H04L 49/103 using a shared central buffer; using a shared memory
• CPC Class Codes: H04L 49/108 using shared central buffer
• CPC Class Codes: H04L 49/1538 Cell slicing
• CPC Class Codes: H04L 49/203 ATM switching fabrics with multicast or broadcast capabilities
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/252 Store and forward routing
• CPC Class Codes: H04L 49/3072 Packet splitting
• CPC Class Codes: H04L 49/3081 ATM peripheral units, e.g. policing, insertion or extraction
• CPC Class Codes: H04L 49/608 ATM switches adapted to switch variable length packets, e.g. IP packets
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 49/9042 : Separate storage for different parts of the packet, e.g. header and payload
• CPC Class Codes: H04L 49/9047 : including multiple buffers, e.g. buffer pools
• CPC Class Codes: H04L 49/9057 : Arrangements for supporting packet reassembly or resequencing
• CPC Class Codes: H04L 69/22 : Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 : Network security protocols
• CPC Class Codes: H04Q 11/0478 : Provisions for broadband connections

Abstract

A method and apparatus for switching a data packet between a source and destination in a network. The data packet includes a header portion and a data portion. The header portion includes routing information for the data packet. The method includes defining a data path in the router comprising a path through the router along which the data portion of the data packet travels and defining a control path comprising a path through the router along which routing information from the header portion travels. The method includes separating the data path and control path in the router such that the routing information can be separated from the data portion allowing for the separate processing of each in the router. The data portion can be stored in a global memory while routing decisions are made on the routing information in the control path.

Claims

1. A method comprising:

receiving, by a network device, data at an input port of the network device;

transferring, by the network device, the data to a memory via an input switch of the network device;

reading, by the network device, a key from a header of the data at the input switch;

identifying, by the network device, a destination and an output port based on the key;

transmitting, by the network device, information identifying the destination and information identifying the output port to an output switch of the network device; and

initiating, by the output switch, transfer of the data from the memory to the output port based on the information identifying the destination and the information identifying the output port.

2. The method of claim 1, further comprising:

generating a notification based on the key and a storage location of the data in the memory; and

where transmitting the information identifying the destination and information identifying the output port includes;

transmitting the notification to the output switch.

3. The method of claim 1, further comprising:

calculating statistical information associated with a transmission of the data to the destination;

storing the statistical information with information identifying a route, associated with the destination, in the memory;

identifying the statistical information and the route based on the key; and

transmitting the statistical information and the data to the destination based on the output port initiating the transfer of the data from the memory.

4. The method of claim 1, further comprising:

performing a search for routing information based on the key; and

identifying the output port based on a result of performing the search for the routing information.

5. The method of claim 1, further comprising:

determining information associated with the data,

the information associated with the data identifying one or more of a source of the data, a flow associated with the data, or a length of the data;

generating a notification based on the information identifying the destination, the information identifying the output port, and the information associated with the data; and

transmitting the notification to the output switch,

the output switch initiating the transfer of the data from the memory based on the notification.

6. The method of claim 1, further comprising:

determining a location of the data in the memory; and

transmitting information identifying the location of the data in the memory to the output switch,

the transfer of the data from the memory being initiated further based on the information identifying the location of the data in the memory being received by the output switch.

7. The method of claim 1,

performing, based on particular bits of data included in the key, a search of a data structure associated with routing the data through the network device to determine a route;

and

identifying the output port based on the determined route.

8. A device comprising:

a memory;

an input switch to;

receive data via an input port of the device, and

transmit the data to the memory, and

determine a key based on a header of the data;

a controller to;

receive the key from the input switch,

determine a route for transmitting the data through the network device based on the key,

identify an output port of the device based on the key, and

transmit, based on the route, information identifying the data and information identifying the output port; and

an output switch to;

receive the information identifying the data and the information identifying the output port, and

initiate a transfer of the data from the memory to the output port based on the information identifying the data and the information identifying the output port.

9. The device of claim 8, where the controller is further to:

generate a notification based on the key and a storage location of the data in the memory, and

transmit the notification to the output switch.

10. The device of claim 8, where the controller is further to:

obtain statistical information associated with a transmission of the data to a particular destination,

identify the statistical information based on the key, and

transmit the statistical information and the data to the particular destination based on the output port initiating the transfer of the data from the memory.

11. The device of claim 8, where the controller is further to:

generate a notification based on the key and a storage location of the data in the memory, and

transmit the notification to the output switch to initiate the transfer of the data from the memory.

12. The device of claim 8, where the controller is further to:

perform a search of routing information based on the key, and

identify the output port based on a result of performing the search of the routing information.

13. The device of claim 8, where the controller is further to:

determine information associated with the data,

the information associated with the data identifying one or more of a source of the data, a flow associated with the data, or a length of the data,

generate a notification based on the information identifying the destination, the information identifying the output port, and the information associated with the data, and

transmit the notification to the output switch to initiate the transfer of the data from the memory.

14. The device of claim 8, where, when determining the route, the controller is further to:

perform, based on particular bits included in the key, a search of a data structure associated with routing the data through the device to determine the route, and

identify the output port based on the route.

15. A system comprising:

a network device to;

receive data at an input port of the network device,

store the data in a memory,

a data path used to transfer the data to the memory flowing directly from the input port to the memory,

read a key from a header of the data,

determine, while the data is stored in the memory, a routing decision based on the key,

the routing decision being made via a control path that is separate from the data path used to transfer the data to the memory,

generate a notification based on the routing decision and a location of the data in the memory,

initiate a transfer of the data from the memory based on the notification, and

transfer the data from the memory to an output port based on the routing decision.

16. The system of claim 15, where the network device is further to:

perform, based on the key, a search of a data structure associated with routing the data through the network device to determine a route, and

identify the output port based on the determined route.

17. The system of claim 16, where the search of the data structure is performed based on particular bits of data included in the key.

18. The system of claim 15, where, when reading the key, the network device is to:

read the key from the header of the data at an input switch of the network device, and

identify a destination and the output port based on the key.

19. The system of claim 18, where the network device is further to:

transmit information identifying the destination and information identifying the output port to an output switch, of the network device, to initiate the transfer of the data from the memory.