Systems and methods of improving performance of transport protocols in a multi-path environment

• US 8,576,875 B2
• Filed: 09/13/2007
• Issued: 11/05/2013
• Est. Priority Date: 09/13/2006
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Sivakumar, Raghupathy, Velayutham, Aravind
• Primary Examiner(s): Rinehart, Mark
• Assistant Examiner(s): KHIRODHAR, MAHARISHI V
• Application Number:
  US11/854,784
• Publication Number:
  US 20080062879A1
• Time in Patent Office: 2,245 Days
• Field of Search: 709/250, 709/206, 709/230, 370/532, 370/417, 370/400
• US Class Current: 370/464
• CPC Class Codes: H04L 45/125 based on throughput or bandwidth
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS
• CPC Class Codes: H04L 61/256 NAT traversal
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols
• 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 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Devices, systems, and methods of improving transport protocol performance in a multi-path environment are disclosed. One network device comprises a transport-layer proxy; and a multi-path traffic distributor coupled to the transport-layer proxy. The transport-layer proxy is configured to receive packets, each associated with a transport-layer connection, from a transport-layer endpoint. The proxy is further configured to deliver at least a portion of the received packets to the multi-path traffic distributor. The multi-path traffic distributor is configured to: assign each of the delivered packets to one of a plurality of data flows, and to transmit each of the delivered packets on an outbound path associated with the assigned data flow.

Claims

1. A network device comprising:

a transport-layer proxy;

a multi-path traffic distributor coupled to the transport-layer proxy; and

a quality of service (QoS) manager;

wherein the transport-layer proxy is configured to;

receive packets, each associated with a transport-layer connection, from a transport-layer endpoint; and

classify the received packets and deliver at least a portion of the received packets to the multi-path traffic distributor based on the classification;

wherein the multi-path traffic distributor is configured to;

independently assign each of the delivered packets to one of a plurality of data flows; and

transmit each of the delivered packets on an outbound path associated with the assigned data flow; and

wherein the quality of service (QoS) manager configured to set the number of data flows in the plurality of data flows to achieve a quality of service specified by traffic classes in use on the transport-layer connections corresponding to the received packets.

2. The network device of claim 1, wherein the outbound path is one of a plurality of outbound paths.

3. The network device of claim 1, wherein the outbound path a single outbound path associated with all of the data flows.

4. The network device of claim 1, wherein the QoS manager is further configured to set the number of data flows to produce relative service differentiation.

5. The network device of claim 1, wherein the QoS manager is further configured to set the number of data flows to produce absolute service differentiation.

6. A network device comprising:

a transport-layer proxy; and

a multi-path traffic distributor coupled to the transport-layer proxy, wherein the transport-layer proxy is configured to;

receive packets, each associated with a transport-layer connection, from a transport-layer endpoint;

store the received packets in buffers associated with the corresponding connections;

wherein the multi-path traffic distributor is configured to;

transmit packets from the buffers to an outbound path;

receive congestion control information from a peer multi-path traffic distributor indicating congestion on the outbound path;

wherein the transport-layer proxy is further configured to;

transmit control packets to the transport-layer endpoint based on occupancy of the buffers, wherein the control packets indicate the congestion control information; and

wherein the multi-path traffic distributor is further configured to;

receive information from the peer multi-path traffic distributor indicating congestion on a path between the peer multi-path traffic distributor and a second transport-layer endpoint, wherein receiving the information is based on occupancy of buffers in the peer multi-path traffic distributor.

7. A network device comprising:

a transport-layer proxy; and

a multi-path traffic distributor coupled to the transport-layer proxy, wherein the transport-layer proxy is configured to;

receive packets, each associated with a transport-layer connection, from a transport-layer endpoint; and

store the received packets in buffers associated with the corresponding connections;

wherein the multi-path traffic distributor is configured to;

transmit packets from the buffers to an outbound path in response to congestion control information received from a peer multi-path traffic distributor indicating congestion on the outbound path; and

wherein the transport-layer proxy is further configured to;

transmit flow control packets to the transport-layer endpoint based on occupancy of the buffers; and

wherein the multi-path traffic distributor is further configured to;

receive information from the peer multi-path traffic distributor indicating receive buffer occupancy in the peer multi-path traffic distributor; and

transmit packets from the buffers to an outbound path in response to the information indicating receive buffer occupancy.

8. A network device comprising:

a transport-layer proxy; and

a multi-path traffic distributor coupled to the transport-layer proxy, wherein the transport-layer proxy is configured to;

receive packets, each associated with a transport-layer connection, from a transport-layer endpoint; and

deliver each of the received packets to the multi-path traffic distributor if the packet is in sequence; and

wherein the multi-path traffic distributor is configured to;

store each of the delivered packets in an unbound buffer which is not assigned to an outbound path; and

transmit each of the delivered packets on an outbound path;

wherein the multi-path traffic distributor is further configured to;

receive packets from a peer multi-path traffic distributor;

store received packets that are not in sequence in an out-of-order buffer; and

deliver packets from the out-of-order buffer to the transport-layer proxy when additional packets have been received from the peer to produce an in-order sequence; and

wherein the transport-layer proxy is further configured to;

store packets delivered from the out-of-order buffer into a receive buffer; and

transmit packets stored in the receive buffer to the transport-layer endpoint.

9. The network device of claim 8, wherein a packet data structure used to store one of the received packets includes a number-of-references field that is increased as each component begins processing of the packet and is decreased as each component completes processing of the packet.

10. The network device of claim 8, further comprising:

logic configured to receive an acknowledgment for a transmitted packet, the acknowledgement including sequence number of the transmitted packet;

logic configured to store the sequence number in response to the received acknowledgment; and

logic configured to delay freeing of memory associated with the transmitted packet to a time later than the received acknowledgment.

11. The network device of claim 8, wherein the multi-path traffic distributor is further configured to:

determining a maximum transmission unit (MTU) for the outbound path;

setting a local MTU to be the MTU for the outbound path reduced by a size of an extended transport-layer protocol header used by the multi-path traffic distributor; and

notifying a peer network device on the outbound path of the local MTU.

12. The network device of claim 8, wherein the network device further comprises:

logic configured to detect presence and capabilities of a peer network device on the outbound path.

13. The network device of claim 8, wherein the network device further comprises:

logic configured to transmit heartbeat messages to a peer network device on the outbound path.