Abstract:
To analyze the performance of a network including edge routers and a hub router coupled together by communication links, an analysis method includes discovering the topology of the network that is initially unknown. An information handling system (IHS) determines baseline performance information with respect to the discovered topology of network, the baseline performance information including network capacity information on a per link basis. The discovered topology of the network is speculatively changed to provide a speculatively changed network with prospects for performance improvement. The IHS determines an estimated impact of the speculative change to the discovered topology of the network by repeating the topology discovery and the determination of baseline performance using the speculative changed topology.

Description:
BACKGROUND 
     The disclosures herein relate generally to information handling systems (IHSs), and more specifically, to communications between IHSs in a network system. 
     Network systems may include information handling systems (IHSs) that couple together via communication routers. The connections of various routers to one another and to the IHSs form a network topology. A network may distribute routers and IHSs among a large number of different geographic locations. It is desirable to configure the network topology to make efficient use of network resources such as communication links among the routers of the network. 
     BRIEF SUMMARY 
     In one embodiment, a method of network performance determination is disclosed. The method includes discovering, by a first information handling system (IHS), a topology of a network that includes a plurality of routers coupled together by a plurality of communication links, the plurality of routers including edge routers and at least one hub router, thus providing a discovered topology. The method includes determining baseline performance information, by the first IHS, with respect to the discovered topology of network, the baseline performance information including network capacity information on a per link basis. The method also includes speculatively changing the discovered topology of the network to provide a speculatively changed network. The method further includes determining, by the first IHS, an estimated impact of the speculative change to the discovered topology of the network by repeating the discovering and determining steps. 
     In another embodiment, a network analysis system is disclosed. The network analysis system includes an information handling system (IHS) that is configured to discover a topology of a network that includes a plurality of routers coupled together by a plurality of communication links, the plurality of routers including edge routers and at least one hub router, thus providing a discovered topology. The IHS is also configured to determine baseline performance information with respect to the discovered topology of the network, the baseline performance information including network capacity information on a per link basis. The IHS is further configured to speculatively change the discovered topology of the network to provide a speculatively changed network. The IHS is also configured to determine an estimated impact of the speculative change to the discovered topology of the network by repeating the discovering and determining steps. 
     In yet another embodiment, a computer program product is disclosed. The computer program product includes a computer readable storage medium. The computer program product also includes first program instructions to discover a topology of a network that includes a plurality of routers coupled together by a plurality of communication links, the plurality of routers including edge routers and at least one hub router, thus providing a discovered topology. The computer program product further includes second program instructions to determine baseline performance information with respect to the discovered topology of network, the baseline performance information including network capacity information on a per link basis. The computer program product still further includes third program instructions to speculatively change the discovered topology of the network to provide a speculatively changed network. The computer program product also includes fourth program instructions to determine an estimated impact of the speculative change to the discovered topology of the network by repeating the discovering of the topology and determining of baseline performance information. The first, second, third and fourth program instructions are stored on the computer readable storage medium. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The appended drawings illustrate only exemplary embodiments of the invention and therefore do not limit its scope because the inventive concepts lend themselves to other equally effective embodiments. 
         FIG. 1  shows a block diagram of a representative network system. 
         FIG. 2  is a block diagram of a network system with modified topology. 
         FIG. 3  is a block diagram of a network system with another modified topology. 
         FIG. 4  is a block diagram of a network system including an information handling system (IHS) that employs the disclosed network analysis methodology. 
         FIG. 5  is a block diagram of the IHS of  FIG. 4 . 
         FIG. 6  is a flowchart of the disclosed network analysis methodology. 
     
    
    
     DETAILED DESCRIPTION 
     In one embodiment, the disclosed methodology evaluates the topology of a network together with network performance information to determine the effect of proposed network changes on network performance. This methodology may assist the network designer in determining how to invest network upgrade resources in an efficient manner. 
     Advanced networks may have a large number of devices and nodes that could benefit from monitoring when making a decision regarding which particular network resources to upgrade. One approach is to collect large amounts of information to determine which particular links are congested and to upgrade bandwidth on those congested links. However, this may not result in the most effective use of network upgrade resources. 
       FIG. 1  shows a network  100  that includes a hub router  105  that couples to edge routers  110 ,  115 ,  120  and  125  via communication links  130 ,  135 ,  140  and  145 , respectively, as shown. A hub router is a router that locates in the interior of a network, whereas an edge router is a router that locates on the edge of a network.  FIG. 1  shows both edge routers and a hub router. Edge router  125  couples to an information handling system (IHS)  150 . Edge router  115  may couple to other IHSs and devices (not shown) via an Internet cloud  155 . Edge routers  110 ,  115 ,  120  and  125  may connect to other IHSs and devices not shown. 
     Network  100  of  FIG. 1  exhibits a “hub and spoke” topology, i.e. a star topology. As network use climbs, it is possible than one of links  130 ,  135 ,  140  and  145  may approach a capacity threshold. For example, link  130  exhibits 80% bandwidth usage. Increases in network traffic may ultimately exceed the bandwidth capabilities of link  130 . In contrast, links  135 ,  140  and  145  exhibit 40%, 40% and 60% bandwidth usage, respectively. 
     One approach to address the high bandwidth consumption on link  130  is seen in  FIG. 2  which shows a modified or upgraded network  100 ′. Upgraded network  100 ′ includes two communication links  130 A,  130 B in place of communication link  130 . This upgraded network topology or configuration reduces the 80% bandwidth consumption of communication link  130  to 40% on each of communication links  130 A,  130 B. 
     While the upgraded network topology of  FIG. 2  does alleviate congestion on communication link  130 , depending on how traffic flows in the network, it may be more cost effective to create a new link between two spokes (i.e. links) because in a star topology such is in network  100 , the majority of traffic flow may be between two spokes of the network. For example, a majority of the traffic between edge router  110  and hub router  105  may actually be traffic between edge router  110  and edge router  125 . In this instance, the upgraded network topology of network  100 ″ of  FIG. 3 , which adds a communication link  305  between edge router  110  and edge router  125 , offers a better investment in upgraded network resources. Adding capacity without understanding traffic flow may result in upgrade resource decisions that are not as efficient as they could be. 
       FIG. 4  shows a network system  400  that includes an IHS  500  that couples to one of the routers of network  405 , for example to edge router  110 . IHS  500  includes an upgrade analysis application  585  that assists the network designer or other entity in evaluating network upgrade changes for improved network performance. IHS  500  also includes a flow collector application  590  that collects traffic flows from the routers of network  400 . In network  405 , each of edge routers  110 ,  115 ,  120  and  125  tracks traffic flows or conversations that pass on the exterior surfaces of the network, the exterior surfaces being formed by the edge routers and respective links  130 ,  135 ,  140  and  145  that couple thereto. A flow or conversation includes all packets that exhibit the same source/destination address pair, the same source/destination port pair and the same class of service. In other words, each edge router groups all packets that exhibit the above common characteristics into a flow. The edge routers  110 ,  115 ,  120  and  125  aggregate their respective flows on a regular basis and send the aggregated volume of traffic in bytes to flow collector application  590  in IHS  500 . Flow collector application  590  collects the aggregated traffic flows from each of edge routers  110 ,  115 ,  120  and  125  and stores these aggregated traffic flows. Flow collector application  590  stores the aggregated traffic flows for each edge router as a series of aggregated traffic flows for each router. Flow collector application  590  may also store the aggregated traffic flow from hub router  105 . 
     Upgrade analysis application  585  performs network discovery on network  405  to determine the topology of network  405 . Initially, upgrade analysis application  585  does not know the topology of network  405 . When upgrade analysis application  585  launches, upgrade analysis application  585  tests network  405  to determine its topology. In other words, upgrade analysis application  585  determines all routers and devices in network  405  and determines the links among those routers and devices. For example, in conducting topology determining operations on network  405 , upgrade analysis application  585  determines that network  405  includes a central hub router  105  with four edge routers  110 ,  115 ,  120  and  125  that couple thereto in a star or “hub and spoke” configuration. In conducting topology determining operations on network  405 , upgrade analysis application  585  also locates the communication links  130 ,  135 ,  140  and  145  between hub router  105  and edge routers  110 ,  115 ,  120  and  125 , respectively. In this manner, upgrade analysis application  585  determines the topology of network  405 . 
     Upgrade analysis application  585  employs the aggregated traffic flows from each of the edge routers as input and determines the network capacity on a “per link” basis using this input. In this manner, upgrade analysis application  585  determines a baseline network capacity on a per link basis before a proposed change is made to network  405 . A user may input a proposed network change to upgrade analysis application  585  and, in response, upgrade analysis application  585  again determines the network capacity on a per link basis. In this manner, the user may see the difference between network capacity on a per link basis both before and after the proposed network change. An example of a proposed change that the user may input to upgrade application  585  is to add a communication link between edge router  110  and edge router  125 , similar to link  305  shown in  FIG. 3 . By comparing the network capacity on a per link basis both before and after the proposed network change, the user may observer whether or not the proposed network change is efficient. 
     The upgrade analysis application  585  combines network discovery information that determines the network topology together with network performance information such as the network capacity on a per link basis to establish a network performance baseline. In one embodiment, the disclosed methodology may display a graphical or block diagram representation of network  405  on a display  540  of IHS  500 . In this manner, upgrade analysis application  585  displays the discovered network topology to the user. Upgrade analysis application  585  may also display the network capacity on a per link basis adjacent each communication link of the topology that display  540  depicts. 
     Upgrade analysis application  585  monitors the flows at the exterior surfaces of the network that the links of network  405  forms. Application  585  monitors both traversing flows and terminating flows. Traversing flows are those flows that enter network  405  and exit network  405  such as those within the dashed line the designates network  405  of  FIG. 4 . In other words, traversing traffic flow are those traffic flows that go into network  405  and then go back out of network  405  without interacting with network  405  other than network  405  providing transportation for those traffic flows. In other words, in the case of traversing traffic flows, the network acts as a transporter without interacting with the traffic. In contrast, terminating traffic flow refers to traffic that goes into network  405  and reaches a destination within network  405  at which point the traffic terminates. Terminating traffic includes at least one end point within network  405 . Upgrade analysis application  585  may also receive aggregated traffic flows from internal routers such as hub router  105  to assist in the evaluation of traffic flow within the network. 
       FIG. 5  is a block diagram of IHS  500  of network system  400  shown  FIG. 4 . IHS  500  is configured to practice the disclosed network analysis methodology. IHS  500  includes a processor  510  that may include multiple cores. IHS  500  processes, transfers, communicates, modifies, stores or otherwise handles information in digital form, analog form or other form. IHS  500  includes a bus  515  that couples processor  510  to system memory  520  via a memory controller  525  and memory bus  530 . In one embodiment, system memory  520  is external to processor  510 . System memory  520  may be a static random access memory (SRAM) array or a dynamic random access memory (DRAM) array. Processor  510  may also includes local memory (not shown) such as L1 and L2 caches (not shown). A video graphics controller  535  couples display  540  to bus  515 . Nonvolatile storage  545 , such as a hard disk drive, CD drive, DVD drive, or other nonvolatile storage couples to bus  515  to provide IHS  500  with permanent storage of information. I/O devices  550 , such as a keyboard and a mouse pointing device, couple to bus  515  via I/O controller  555  and I/O bus  560 . 
     One or more expansion busses  565 , such as USB, IEEE 1394 bus, ATA, SATA, PCI, PCIE, DVI, HDMI and other busses, couple to bus  515  to facilitate the connection of peripherals and devices to IHS  500 . A network interface adapter  505  couples to bus  515  to enable IHS  500  to connect by wire or wirelessly to a network and other information handling systems. In this embodiment, network interface adapter  505  may also be called a network communication adapter or a network adapter. While  FIG. 5  shows one IHS that employs processor  510 , the IHS may take many forms. For example, IHS  500  may take the form of a desktop, server, portable, laptop, notebook, or other form factor computer or data processing system. IHS  500  may take other form factors such as a gaming device, a personal digital assistant (PDA), a portable telephone device, a communication device or other devices that include a processor and memory. 
     IHS  500  includes a network upgrade analysis computer program product on digital media  575  such as a CD, DVD or other media. In one embodiment, digital media  575  includes an application  585  that are configured to practice the disclosed network analysis methodology. Digital media  575  may also store flow collector application  590 . In practice, IHS  500  may store an operating system  581  (OPERATING SYS), application  585  and flow collector application  590  on nonvolatile storage  545  as operating system  581 ′, application  585 ′ and application  590 . When IHS  500  initializes, the IHS loads operating system  581 ′ into system memory  420  for execution as operating system  581 ″. IHS  500  also loads application  585 ′ into system memory  520  as application  585 ″. IHS  500  further loads application  590 ′ into system memory  520  as application  590 ″. 
     As will be appreciated by one skilled in the art, aspects of the disclosed network upgrade analysis method may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product, such as CPP  575  embodied in one or more computer readable medium(s) having computer readable program code embodied thereon. 
     Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing. 
     Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). 
     Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart of  FIG. 6  illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart of  FIG. 9  and/or block diagram block or blocks. 
     These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart of  FIG. 6  described below. 
     The flowchart of  FIG. 6  illustrates the architecture, functionality, and operation of possible implementations of systems, methods and computer program products that perform network analysis in accordance with various embodiments of the present invention. In this regard, each block in the flowchart of  FIG. 6  may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in  FIG. 6 . For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of  FIG. 6  and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. 
       FIG. 6  is a flowchart that depicts the process steps that upgrade analysis application  585  of IHS  500  performs to carry out one implementation of the disclosed network analysis methodology. Process flow commences at start block  605  at which IHS  500  initializes and launches operating system  581 , upgrade analysis application  585 ′ and flow collector application  590 ′. Upgrade analysis application  585 ″ tests network  405  and determines the topology of network  405 , as per block  610 . In the particular network topology example of  FIG. 4 , application  585 ″ determine the existence of hub router  105  and edge routers  110 ,  115 ,  120  and  125 . Upgrade analysis application  585 ″ also determines the communication links  130 ,  135 ,  140  and  145  between the hub router and the edge routers. 
     Upgrade analysis application  585 ″ also gathers interface-based performance information, as per block  615 . Each router couples to a communication link via a communication interface (not shown). Each router includes multiple communication interfaces for respective communication links. Upgrade analysis application  585 ″ gathers interface-based performance information from these communication interfaces that couple the routers to the communication links. An example of the gathered interface-based performance information is Simple Network Management Protocol (SNMP) performance information. For example, the method instruments an individual port or virtual port on a particular router to obtain interface-based performance information from that router. The method may instrument multiple ports in this manner to obtain performance information from multiple ports on multiple routers in network  405 . 
     Upgrade analysis application  585 ″ gathers flow information, as per block  620 . For example, application  585 ″ collects aggregated flows from each hub router such as router  105  and edge routers  110 ,  115 ,  120  and  125 . Upgrade analysis application  585 ″ stores the aggregated flows for each router of network  405  as a series of aggregated flows for each router. In actual practice, upgrade analysis application  585 ″ may use flow collector application  590  to collect and store this flow information. 
     Upgrade analysis application  585 ″ applies the performance information to the topology information, as per block  625 . Upgrade analysis application  585 ″ credits the interfaced-based performance information or port information to the topology to determine the bandwidth performance on each of the communication links of the topology, as per block  630 . Links may be assigned different line widths, different colors and other visual distinctions to show the respective bandwidth used for each link and total bandwidth. The upgrade analysis application  585 ″ then causes the display  540  of IHS  500  to show the discovered network topology together with the credited performance information for each communication link, as indicated by the above described visual distinctions, per block  635 . By observing this display, the user may judge which particular link or links are congested and in need of a resource upgrade. It may be more effective to add a link between edge routers, such as between edge routers  110  and  125 , rather than add another link between hub router  105  and edge router  110  in some applications. In this manner, the user may or may not identify a problem with the current topology at decision block  640 . If the user finds no network performance problem using the current topology, then the upgrade analysis application  585 ″ terminates at end block  645 . However, if the user identifies a network performance problem at decision block  640  by looking at display  540 , then the user may alter the topology and observe the resultant network performance effects, as per block  650 . More particularly, the user alters the topology and process flow continues back to block  610  at which the network upgrade analysis process begins again, except using the new candidate network topology. If the new candidate network topology exhibits superior network performance in comparison with the previous topology, then the user may decide to make the appropriate investment in network infrastructure to implement the candidate topology, for example by adding an appropriately positioned communication link between routers. 
     As will be appreciated by one skilled in the art, aspects of the disclosed memory management technology may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.