System and method for a software-based TCP/IP offload engine for digital media renderers

• US 20080117911A1
• Filed: 03/13/2007
• Published: 05/22/2008
• Est. Priority Date: 11/21/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rajakarunanayake, Yasantha, Severin, Lars
• Granted Patent: US 7,773,546 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/40 using split connections
• CPC Class Codes: H04L 65/764 at the destination reformatting of additional data in video clients H04N21/4355
• 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 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

A method of receiving data from a first computing device to a second computing device through a network is disclosed. The transfer adheres to a packet-based network protocol. A connection between the first and second computing devices is established according to the protocol. A data packet is received from the first device at the second device, where the data packet includes payload data and a header. A packet header template is defined for acknowledging receipt of the data packet, and the template has static fields filled with static values and variable fields that can acquire packet-dependent values. The header template is stored in a memory device of the second device. Packet-dependent values of the variable fields of the template are updated. An ACK packet that includes a copy of the updated packet header is sent from the first computing device to the second computing device to acknowledge the receipt of the packet.

Claims

1. A method of receiving data transferred from a first computing device to a second computing device through a network, the transfer of data adhering to a packet-based network protocol the method comprising:

establishing a connection between the first computing device and the second computing device for a session according to the network protocol;

receiving a data packet from the first computing device at the second computing device, wherein the data packet includes payload data and a header;

defining a packet header template for acknowledging the receipt of the data packet, the template having a plurality of static fields filled with static values and variable fields that can acquire packet-dependent values;

storing the header template in a memory location of a memory device of the second computing device;

updating the packet-dependent values of the variable fields of the template stored in the memory device; and

sending an ACK packet that includes the a copy of the updated packet header from the first computing device to the second computing device to acknowledge the receipt of the packet.

2. The method of claim 1, wherein the network is a wireless network.

3. The method of claim 1, wherein the protocol comprises TCP/IP and wherein a variable field is adapted for carrying the value of a sequence number identifying the ACK packet within a sequence of a plurality of ACK packets sent from the first computing device to the second computing during the session.

4. The method of claim 1, wherein the protocol comprises TCP/IP and wherein a variable field is adapted for carrying the value of an acknowledgement number corresponding to the value of a sequence number of the received data packet.

5. The method of claim 1, wherein the protocol comprises TCP/IP and wherein the static fields include a source field, a destination field, and a window size field, wherein the variable fields include a checksum field, and the method further comprising:

performing a checksum analysis on the data packet and adding the result of the checksum analysis to the checksum field.

6. The method of claim 1, wherein the protocol comprises TCP/IP and further comprising writing updated packet-dependent values from a CPU cache to the template stored in the memory, wherein at least one static value used in ACK packet header is not written from the template to the CPU cache and back to the memory device.

7. The method of claim 1, further comprising routing the payload data to a video display device.

8. A method of receiving data transferred from a first computing device to a second computing device through a network, the transfer of data adhering to a TCP/IP protocol, the method comprising:

establishing a connection between the first computing device and the second computing device for a session according to the TCP/IP protocol;

receiving a data packet from the first computing device at the second computing device, wherein the data packet includes payload data and a header;

defining a packet header template for acknowledging the receipt of the data packet, the template having a plurality of static fields filled with static values and variable fields that can acquire packet-dependent values;

storing the header template in a memory location;

assigning a sequence number value with a central processing unit of the second computing device to the sequence number field of the header template;

assigning an acknowledgement number value with the central processing unit to the acknowledgement number field of the header template; and

then

sending an ACK packet that includes a copy of the packet header template, including the assigned acknowledgement and sequence numbers, from the second computing device to the first computing device to acknowledge the receipt of the packet.

9. The method of claim 8, wherein when the data packet corresponds to an expected packet, the acknowledgment number value is equal to a value of data packet'"'"'s sequence number plus a length of the received data packet.

10. The method of claim 8, wherein when the data packet corresponds to an unexpected packet, the acknowledgment number value is equal to the value of an acknowledgement number of an ACK packet that was previously-sent from the second computing device to the first computing device.

11. The method of claim 8, wherein the sequence number value is equal to an acknowledgement number value of the received data packet.

12. The method of claim 8, wherein the network is a wireless network.

13. The method of claim 8, wherein the first computing device is a settop gateway and the second computing device is a settop client, and wherein both computing devices are located within the same building.

14. A playback computing-device for receiving data transferred from a streaming computing through a network, the transfer of data adhering to a TCP/IP protocol, the playback computing-device comprising:

a central processing unit;

a random access memory;

a network interface device; and

a memory for storing computer-executable instructions, that when executed;

cause the network interface device to establish a connection with the playback computing device for a session according to the TCP/IP protocol;

cause the central processing unit to define a packet header template and store the header template in the random access memory, the template having a plurality of static fields filled with static values and variable fields that can acquire packet-dependent values, wherein the variable fields include a sequence number field and an acknowledgement number;

cause the central processing unit to assign sequence number values to the sequence number fields of the header template for each of the plurality of packets;

cause the central processing unit to assign acknowledgement number values to the acknowledgement number fields of the header template for each of the plurality of packets; and

cause the network interface device to send ACK packets to the streaming computing device to acknowledge the receipt of a data packets, wherein the ACK packets include a copy of the packet header template, including the assigned acknowledgement and sequence numbers.

15. The playback computing-device of claim 14, wherein the network is a wireless network.

16. The playback computing-device of claim 14, wherein the streaming computing device is a settop gateway and the playback computing device is a settop client, and wherein both computing devices are located within the same building.

17. The playback computing-device of claim 14, further comprising a buffer, and wherein the memory further comprises computer-executable instructions that when executed cause the playback computing device to:

store data packets received from the streaming computing device in the buffer;

determine whether a received data packet is an expected data packet; and

when the received data packet is an expected data packet to send the ACK packet with an acknowledgment number value that is equal to a value of received data packet'"'"'s sequence number plus a length of the received data packet.

18. The playback computing-device of claim 14, further comprising a buffer, and wherein the memory further comprises computer-executable instructions that when executed cause the playback computing device to:

store data packets received from the streaming computing device in the buffer;

determine whether a received data packet is an expected data packet; and

when the received data packet is not an expected data packet to send an ACK packet having an acknowledgment number value that is equal to the value of an acknowledgement number value of an ACK packet that was previously-sent to the streaming computing device.

19. The playback computing-device of claim 14, wherein the sequence number values are equal to an acknowledgement number value of data packets received from the streaming computing device.

20. The playback computing-device of claim 14, wherein the central processing unit, the random access memory, the memory, and the network interface device are located within a system on a chip.