Method and system for scaling network traffic managers

• US 7,395,349 B1
• Filed: 08/20/2003
• Issued: 07/01/2008
• Est. Priority Date: 05/24/2001
• Status: Active Grant

• Current Assignee: F5 Networks, Inc. (F5 Incorporated)
• Original Assignee: F5 Networks, Inc. (F5 Incorporated)
• Inventors: Schmitt, David D., Szabo, Paul, Li, Ning X.
• Primary Examiner(s): SALAD, ABDULLAHI ELMI
• Application Number:
  US10/644,692
• Time in Patent Office: 1,777 Days
• Field of Search: 709/238, 709/245
• US Class Current: 709/238
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]

Abstract

A method and system is directed to routing a flow of packets over a network to multiple traffic management devices. An apparatus receives each packet from a network and forwards the packet to one of a group of traffic management devices. The apparatus also may receive packets from servers for which the traffic management devices are managing communications. When forwarding packets, a traffic management device is selected from the group of traffic management devices by employing a hash of an IP address and port number. The IP address and port number are selected from source or destination information in the packet that has a greater port number. When the traffic management device performs a network address translation, further actions may be performed so that packets that are part of a flow between two network devices are delivered to the same traffic management device.

Claims

1. An apparatus for routing packets over a network, the packets comprising a first packet type and a second packet type, wherein each packet of the first packet type has a corresponding packet of the second packet type, the apparatus comprising:

(a) a transceiver configured to receive and to forward each packet; and

(b) a processor, coupled to the transceiver, that is arranged to perform actions, including;

if the received packet is of the first packet type, forwarding the received packet to a first traffic manager that is selected based on at least a first field in the received packet, wherein forwarding the received packet further comprises hashing the first field in the received packet to obtain a hash key and employing the hash key to select the first traffic manager to which the packet is forwarded; and

if the received packet is of the second packet type, forwarding the received packet to a second traffic manager that is selected based on at least a second field in the received packet, wherein the first traffic manager is the same as the second traffic manager when the received packet of the first packet type corresponds to the received packet of the second packet type.

2. The apparatus of claim 1, wherein the first field of the first packet type includes a first value substantially equivalent to a second value in the second field of a corresponding packet of the second packet type.

3. The apparatus of claim 1, wherein the first packet type further comprises a packet in a first direction, and the second packet type further comprises a packet in a second direction.

4. The apparatus of claim 1, further comprising determining the packet type of the received packet in part by comparing a source port number with a destination port number.

5. The apparatus of claim 1, wherein the first field further comprises at least one of a source IP address and a source port number, and the second field further comprises at least one of a destination IP address and a destination port number.

6. The apparatus of claim 1, wherein employing the hash key to select the first traffic manager further comprises using the hash key as an index into an allocation table of traffic managers.

7. The apparatus of claim 1, wherein the processor is arranged to perform actions, further comprising, if the received packet is other than a TCP packet or a User Datagram Protocol (UDP) packet, forwarding the received packet to a third traffic manager that is selected using the first field and the second field in the received packet.

8. The apparatus of claim 1, wherein the apparatus is arranged to operate as at least one of a distributor, a router, a bridge, a firewall, and a gateway.

9. The apparatus of claim 1, wherein the processor is arranged to perform actions, further comprising, if the received packet is associated with a pre-determined group characteristic, selecting the first traffic manager and the second traffic manager from a plurality of traffic managers that are partitioned into groups of traffic managers based in part on the pre-determined group characteristic.

10. The apparatus of claim 9, wherein the pre-determined group characteristic further comprises at least one of a Secure Socket Layer (SSL) packet, Domain Name System (DNS) packet, and a UDP packet.

11. A method of routing packets between a first network device and a second network device over a network, comprising:

receiving a packet;

if the received packet is from the first network device;

determining a target traffic manager based on at least a first field in the received packet, by hashing at least the first field in the received packet to obtain a hash key and employing the hash key to select the target traffic manager to which the received packet is forwarded, and

forwarding the received packet to the target traffic manager; and

if the received packet is from the second network device;

determining the target traffic manager based on at least a second field in the received packet, wherein the first field is different from the second field; and

forwarding the received packet to the target traffic manager, wherein the received packet from the second network device is forwarded to the same target traffic manager as is the received packet from the first network device.

12. The method of claim 11, further comprising determining whether the received packet is from the first network device based on a comparison of a first packet header field and a second packet header field.

13. The method of claim 11, wherein the first field further comprises at least one of a source IP address and a source port number, and the second field further comprises at least one of a destination IP address and a destination port number.

14. The method of claim 11, wherein determining the target traffic manager further comprises:

employing the hash key as an index into an allocation table of traffic managers.

15. A method for routing a packet over a network, comprising:

(i) receiving the packet;

(ii) if the received packet is a packet of a first type, forwarding the received packet to a first traffic manager that is selected based in part on a first field in the received packet in part by hashing the first field to obtain a hash key and employing the hash key to select the first traffic manager, wherein a response packet to the received packet is forwarded to the first traffic manager; and

(iii) if the received packet is a packet of a second type, forwarding the received packet to a second traffic manager that is selected based in part on a second field in the received packet, wherein the response packet is forwarded to the second traffic manager and wherein the second field in the received packet is hashed to obtain another hash key that is used to select the second traffic manager.

16. The method of claim 15, wherein receiving the packet further comprises determining the packet type of the received packet based in part on comparing source information with destination information in the received packet.

17. The method of claim 15, wherein a packet of the first type further comprises a packet that includes a source port number that is greater than a destination port number.

18. The method of claim 15, wherein a packet of the second type further comprises a packet that includes a destination port number that is greater than a source port number.

19. The method of claim 15, wherein the first field in the received packet further comprises a source IP address and the source port number, and the second field in the received packet further comprises a destination IP address and the destination port number.

20. The method of claim 15, further comprising, if the first field in the received packet equals the second field in the received packet, forwarding the received packet to a pre-determined traffic manager.

21. The method of claim 15, further comprising, if source information in the received packet is to be translated, replacing a source port number in the received packet with another source port number, wherein the other source port number is greater than a destination port number associated with the received packet.

22. The method of claim 21, wherein the other source port number is selected from a pre-computed self-source port table.

23. A system for routing a packet over a network, comprising:

(a) a plurality of servers;

(b) a plurality of traffic managers arranged to direct the packet to at least one of the plurality of servers; and

(c) a distributor, coupled to the plurality of traffic managers, that is arranged to perform actions, including;

(i) if the received packet is a first packet type, forwarding the received packet to a first traffic manager in the plurality of traffic managers that is selected using in part a first field in the received packet by hashing the first field to obtain a hash key used to select the first traffic manager, wherein a response packet to the received packet is forwarded to the first traffic manager; and

(ii) if the received packet is a second packet type, forwarding the received packet to a second traffic manager in the plurality of traffic managers that is selected using in part a second field in the received packet by in part hashing the second field to obtain another hash key used to select the second traffic manager, wherein the response packet is forwarded to the second traffic manager.

24. The system of claim 23, wherein the first packet type includes a source port number in the received packet that is greater than a destination port number in the received packet, and a second packet type includes a destination port number in the received packet that is greater than a source port number in the received packet.

25. The system of claim 23, wherein using in part the first field further comprises using a source IP address and a source port number in the received packet.

26. The system of claim 24, wherein using the part the second field further comprises using a destination IP address and a destination port number in the received packet.

27. The system of claim 23, wherein in part hashing the first field further comprises:

hashing a source IP address and a source port number in the received packet to obtain the hash key; and

employing the hash key to select the first traffic manager to which the received packet is forwarded.

28. The system of claim 27, wherein hashing the source IP address includes employing a hash function that is configured to load balance the plurality of traffic managers.

29. The system of claim 23, wherein the distributor is arranged to perform actions, further comprising, if the received packet is associated with a pre-determined group characteristic, selecting the traffic manager and the other traffic manager from a plurality of traffic managers that are partitioned into groups of traffic managers based in part on the pre-determined group characteristic.