WO2015119591A1

WO2015119591A1 - Network switch extension

Info

Publication number: WO2015119591A1
Application number: PCT/US2014/014543
Authority: WO
Inventors: Jechun CHIU; Craig Joseph MILLS; Tomas Kubica
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2014-02-04
Filing date: 2014-02-04
Publication date: 2015-08-13

Abstract

Disclosed herein are a system, non-transitory computer readable medium, and method for extending a network switch. A first amount of memory of a network switch is extended or supplemented with a second amount of memory. Additional logic is implemented over that of the network switch.

Description

NETWORK SWITCH EXTENSION

BACKGROUND

[0001] Telecommunication networks today may transfer information in packets of data ("packet switching"). Application specific integrated circuits ("ASICS") have been used to deal with such data packets. Such ASICS have specific features or architectures that are designed to enhance and optimize packet processing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] FIG. 1 is an example system in accordance with aspects of the present disclosure.

[0003] FIG. 2 is an example flow diagram in accordance with aspects of the present disclosure.

[0004] FIG. 3 is an example implementation in accordance with aspects of the present disclosure.

[0005] FIG. 4 is a further example implementation in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

[0006] As noted above, network processors or ASICS may be used to process packets of data. Data packet processing may include a control plane that determines where to route a packet and a data plane that simply forwards the packet to destinations determined at the control plane. Recently, alternate approaches to packet processing have evolved. For example, software defined networking ("SDN") decouples the control plane and the data plane in order to abstract lower levels of functionality. SDN systems may utilize a protocol to define a standard of communication between the control plane and the data plane. Through the use of such protocols, the path of a data packet may be determined by software executing in a router or switch. This separation between the control and data plane may permit more sophisticated traffic management.

[0007] While SDN has grown in popularity, ASICs have limited flexibility and functionality that cannot change at the pace SDN is evolving. Static resources contained in ASICS prevent some networking systems from taking full advantage of the SDN architecture. For example, connections between an SDN switch and a controller are currently limited to on board packet processing capabilities of an existing ASIC, which in many instances cannot scale to the needs of SDN applications. Furthermore, as modern SDN protocols change and mature, ASIC tables are required to meet certain protocol specifications. Unfortunately, meeting such specifications may be complex and expensive. Some of the requirements may not even be possible to implement due to limitations in some ASICs.

[0008] In view of the foregoing, disclosed herein are a system, non-transitory computer readable medium, and system for extending a network switch. In one aspect, a first amount of memory of a network switch is extended to or supplemented with a second amount of memory. In a further example, additional logic is implemented over the logic of the network switch. The subject matter of the present disclosure provides a solution that may overcome the lack of flexibility, programmability, and resource limitations of a fixed ASIC SDN implementation. The techniques disclosed herein may also enhance the ability to abstract a network switch by providing additional logic that may be reprogrammed without affecting underlying switch firmware. Furthermore, the solutions provided herein may permit fixed ASICS to scale by permitting a distributed implementation of SDN policy. In addition, by extending or supplementing the memory of a network switch, a switch's virtual table space may be extended. For example, by extending its memory, a network switch may appear like it has more ternary content addressable memory space ("TCAMS") than it actually contains. The aspects, features and advantages of the present disclosure will be appreciated when considered with reference to the following description of examples and accompanying figures. The following description does not limit the application; rather, the scope of the disclosure is defined by the appended claims and equivalents.

[0009] FIG. 1 presents a schematic diagram of an illustrative computer apparatus 100 for executing the techniques disclosed herein. Computer apparatus 100 may comprise any device capable of processing instructions and transmitting data to and from other computers, including a laptop, a full-sized personal computer, a high-end server, or a network computer lacking local storage capability. Computer apparatus 100 may include all the components normally used in connection with a computer. For example, it may have a keyboard and mouse and/or various other types of input devices such as pen-inputs, joysticks, buttons, touch screens, etc., as well as a display, which could include, for instance, a CRT, LCD, plasma screen monitor, TV, projector, etc. Computer apparatus 100 may also comprise a network interface (not shown) to communicate with other devices over a network.

[0010] The computer apparatus 100 may also contain a processor 1 10, which may be any number of well known processors, such as processors from Intel ® Corporation. In another example, processor 1 10 may be an application specific integrated circuit ("ASIC"). Non-transitory computer readable medium ("CRM") 1 12 may store instructions that may be retrieved and executed by processor 1 10. As will be discussed in more detail below, the instructions may include a switch extension 1 14. In one example, non-transitory computer readable medium ("CRM") 1 12 may be used by or in connection with any instruction execution system that can fetch or obtain the logic from non-transitory CRM 1 12 and execute the instructions contained therein.

[0011] Non-transitory CRM 1 12 may comprise any one of many physical media such as, for example, electronic, magnetic, optical, electromagnetic, or semiconductor media. More specific examples of suitable non-transitory computer- readable media include, but are not limited to, a portable magnetic computer diskette such as floppy diskettes or hard drives, a read-only memory ("ROM"), an erasable programmable read-only memory, a portable compact disc or other storage devices that may be coupled to computer apparatus 100 directly or indirectly. The non-transitory CRM 1 12 may also include any combination of one or more of the foregoing and/or other devices as well. While only one processor and one non-transitory CRM are shown in FIG. 1 , computer apparatus 100 may actually comprise additional processors and memories that may or may not be stored within the same physical housing or location. Thus, although all the components of computer apparatus 100 are functionally illustrated as being within the same block, it will be understood that the components may or may not be stored within the same physical housing. [0012] The instructions of residing in non-transitory CRM 1 12 may comprise any set of instructions to be executed directly (such as machine code) or indirectly (such as scripts) by processor 1 10. In this regard, the terms "instructions," "scripts," or "modules" may be used interchangeably herein. The computer executable instructions may be stored in any computer language or format, such as in object code or modules of source code. Furthermore, it is understood that the instructions may be implemented in the form of hardware, software, or a combination of hardware and software and that the examples herein are merely illustrative.

[0013] In one example, a switch extension may instruct processor 1 10 to implement additional logic over that of a network switch and to extend the first amount of memory to a second amount of memory larger than the first. In a further example, the network switch extension disclosed herein may be an SDN switch extension such that the SDN capabilities of the underlying switch are enhanced. Thus, it is understood that the network switch extension disclosed herein may comply with any number of SDN protocols including, but not limited to, proprietary protocols, simple network management protocol ("SDN"), network configuration protocol ("NETCONF"), Openflow, and/or command line interface ("CLI") based commands.

[0014] Working examples of the system, method, and non-transitory computer readable medium are shown in FIGS. 2-4. In particular, FIG. 2 illustrates a flow diagram of an example method 200 for extending a network switch. FIGS. 3-4 show a working example in accordance with the techniques disclosed herein. The actions shown in FIGS. 3-4 will be discussed below with regard to the flow diagram of FIG. 2.

[0015] Referring now to FIG. 2, the memory of a network switch may be extended or supplemented, as shown in block 202. Furthermore, logic may be implemented in addition to the logic of the network switch, as shown in block 204. Referring now to FIG. 3 an example implementation of the techniques disclosed herein are shown. FIG. 3 shows a chassis 300 housing network switches 304, 306, 308, 310, and 314 and a blade server 312. Blade server 312 and the network switches 306, 308, 310, and 314 may each comprise a thin, modular electronic circuit board, containing at least one processor and memory and optionally permanent storage. Furthermore, the blade server and network switches may have a connectivity that screws into a slot on a standard space-saving computer rack within chassis 300. The modules within chassis 300 of FIG. 3 may share a power supply, fans, and a backbone. The connectivity of the blade servers and network switches to the backbone may be proprietary or standards-based (e.g., PCI-E and/or Ethernet backplane).

[0016] The blade server and network switches may be used in conjunction to forward packets to destinations determined by controller 316. Controller 316 may use a routing algorithm to determine where to route a data packet. Main module 302 may orchestrate or otherwise manage the blade server and network switches within chassis 300 and balance the workload among them. The storage required by the blades and network switches could be embedded therein, or available externally via standard connectivity mechanisms such as Storage Area Networks ("SAN"), or Network Attached Storage ("NAS"). For example, the operating system and applications required to operate blade server 312 may be loaded from the storage device(s) available thereto.

[0017] In the example implementation of FIG. 3, blade server 312 may comprise a network switch extension in accordance with aspects of the present disclosure. Thus, blade server 312 may extend the memory of each network switch (e.g., Network switch 304, 306, 308, 310, and 314) and implement additional logic over that of each network switch. The additional logic may include, but not be limited to, enabling a network switch to comply with a different SDN protocol or different SDN protocol version, and perform additional processing on packets before forwarding the packets, such as providing additional features and functionality that augment the existing behavior and capabilities of a network switch. By way of example, the existing behavior may be augmented to implement deep packet inspection and matching to trigger events. Thus, blade server 312 may behave as an SDN protocol proxy or translator. Moreover, blade server 312 may cause each network switch in chassis 300 to appear as if it contains more memory and computing capacity than it actually has. From the perspective of controller 316, blade server 312 is the network switch and, from the perspective of each network switch in chassis 300, blade server 312 is the controller. In another example, blade server 312 may associate one network switch with a plurality of network switches, but may still provide a controller with an appearance of a single network switch. The additional logic provided by blade server 312 may permit the network switches within chassis 300 to adjust to changes in controller 316. For example, if controller 316 is upgraded to a new protocol, only blade server 312 would need to be adjusted. Thus, from the perspective of controller 316, each network switch would comply with the new protocol.

[0018] By way of example, blade server 312 may provide an appearance that each network switch in chassis 300 comprises more virtual table space by supplementing that virtual table space with a second virtual table space. By way of further example, blade server 312 may supplement the TCAM space of each network switch with a second TCAM space larger than the first. TCAM is widely used for searching information in network switches by using certain content of a message as an input for the TCAM search. The TCAM may compare the input with all table entries stored therein. When a completely matched table entry is found, the TCAM may trigger the execution of some action associated with the table entry (e.g., discarding the message, allowing to forward the message, or modifying certain information of the message). By way of example, a destination IP address of an input message may be taken as input to the TCAM to search information related to the next hop.

[0019] Referring to FIG. 4, an alternate implementation of the techniques disclosed herein is provided. In this example, switch extension 404 may execute in a proxy server 402 and may behave as the SDN protocol proxy for controller 406 and switch 408. As with the blade server discussed above, switch extension 404 may extend the memory of switch 408 and may implement additional logic in addition to that of switch 408 to comply with other protocols than the protocol actually configured in switch 408 or to augment other behavior of switch 408. Also, as with the network switch and the controller discussed above, proxy server 402, switch 408, and controller 406 may be interconnected via a network that may use various protocols including virtual private networks, local Ethernet networks, private networks using communication protocols proprietary to one or more companies, cellular and wireless networks, HTTP, and various combinations of the foregoing. Although proxy server 402 is depicted as being a single computer, it should be appreciated that proxy server 402 may comprise additional interconnected computers, such as a load balancing cluster.

[0020] Advantageously, the above-described system, non-transitory computer readable medium, and method extend the capabilities of a legacy network switch. In this regard, the legacy network switch can be made to appear as a cutting edge, high-bandwidth switch with the latest features. Thus, the network extension disclosed herein may be used and adjusted indefinitely or until the underlying legacy ASIC is replaced. In turn, users of such legacy network switches may be able to upgrade without having to change the firmware of the network switch, which can be burdensome and time consuming.

[0021] Although the disclosure herein has been described with reference to particular examples, it is to be understood that these examples are merely illustrative of the principles of the disclosure. It is therefore to be understood that numerous modifications may be made to the examples and that other arrangements may be devised without departing from the spirit and scope of the disclosure as defined by the appended claims. Furthermore, while particular processes are shown in a specific order in the appended drawings, such processes are not limited to any particular order unless such order is expressly set forth herein. Rather, various steps can be handled in a different order or simultaneously, and steps may be omitted or added.

Claims

1 . A system comprising:

a network switch which upon execution instructs at least one processor to forward data packets to network destinations, the network switch being configured with a first protocol and a first amount of memory; and

a switch extension which upon execution instructs at least one processor to implement additional logic over that of the network switch and to extend the first amount of memory to a second amount of memory larger than the first.

2. The system of claim 1 , wherein the switch extension adds to a virtual table space of the network switch.

3. The system of claim 2, wherein the switch extension upon execution instructs at least one processor to associate a plurality of network switches with the network switch.

4. The system of claim 1 , wherein the switch extension is contained in a switch chassis.

5. The system of claim 1 , wherein the switch extension is software defined network switch extension.

6. A non-transitory computer readable medium having instructions therein which, if executed, cause at least one processor to:

establish communication with a network switch that forwards data packets to network destinations;

supplement a first amount of memory in the network switch with a second amount of memory; and

implement additional logic over that of the network switch.

7. The non-transitory computer readable medium of claim 6, wherein the instructions therein upon execution further instructs at least one processor to supplement a virtual table space of the network switch with a second virtual table space.

8. The non-transitory computer readable medium of claim 6, wherein the instructions therein upon execution further instructs at least one processor to associate a plurality of network switches with the network switch.

9. The non-transitory computer readable medium of claim 6, wherein the instructions therein further instruct at least one processor to supplement a ternary content addressable memory space of the network switch with a second ternary content addressable memory space.

10. The non-transitory computer readable medium of claim 9, wherein the network switch is an application specific integrated circuit.

1 1 . A method comprising

establishing, using at least one processor, communication with a network switch that forwards data packets to network destinations, the network switch being configured with a first protocol and a first amount of memory;

extending, using at least one processor, the first amount of memory in the network switch to a second amount of memory larger than the first; and implementing, using at least one processor, additional logic over that of the network switch.

12. The method of claim 1 1 , further comprising extending, using at least one processor, a virtual table space of the network switch.

13. The method of claim 12, further comprising associating, using at least one processor, a plurality of network switches with the network switch.

14. The method of claim 1 1 , further comprising extending, using at least one processor, a ternary content addressable memory space of the network switch.

15. The method of claim 1 1 , wherein the network switch is an application specific integrated circuit.