Patent Publication Number: US-8116433-B2

Title: Calls per second network testing

Description:
NOTICE OF COPYRIGHTS AND TRADE DRESS 
     A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever. 
     BACKGROUND 
     1. Field 
     This disclosure relates to network communications testing involving voice calls. 
     2. Description of the Related Art 
     Networks such as the Internet carry a variety of data communicated using and through a variety of network devices including servers, routers, hubs, switches, and other devices. Before placing a network into use, the network, including the network devices, network media, network segments and network applications included therein, may be tested to ensure successful operation. Network devices and applications may be tested, for example, to ensure that they function as intended, comply with supported protocols, and can withstand anticipated traffic demands. Such testing may also be performed on already deployed network devices, network segments and network applications. 
     To assist with the construction, installation and maintenance of networks, network applications and network devices, networks may be augmented with network analyzing devices, network conformance systems, network monitoring devices, and network traffic generators, all which are referred to herein as network testing systems. The network testing systems may allow for analyzing the performance of networks, network applications and network devices by capturing, modifying, analyzing and/or sending network communications. The network testing systems may also be used to evaluate how well a network device or network segment handles data communication, streaming media and voice communications. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an environment in which calls per second network testing may be implemented. 
         FIG. 2  is a flow chart of actions taken to implement calls per second network testing. 
         FIG. 3  is a screen shot of a graphical user interface provided to a user to achieve calls per second network testing. 
     
    
    
     DETAILED DESCRIPTION 
     Apparatus 
       FIG. 1  is a block diagram of an environment in which calls per second network testing may be implemented. The environment  100  shows a network testing system  110  in which methods for receiving, processing and executing network tests may be implemented. The network test may be system default tests and may be user modified or user specified. The environment  100  includes network testing system  110  coupled via at least one network card  120  to a network  140  over a communications medium  144 . The network testing system  110  may include or be one or more of a performance analyzer, a conformance validation system, a network analyzer, a packet blaster, a network management system, a combination of these, and/or others. 
     The network testing system  110  may be used to evaluate or measure characteristics and performance of a network communication medium, a network application, a network communications device or system, including the throughput of network traffic, the number of dropped packets, jitter, packet delay, and many others. Such testing may be used to evaluate the Mean Opinion Score (MOS) or R-value score of a voice transmission, a video quality score or rating, a broadband quality score, or other similar media transmission score for a communication over a network or portion thereof and/or through a network communications device. The network testing system may be used to evaluate the performance of servers, network communications devices such as, for example, routers, gateways, firewalls, load balancers, and other network devices, as well as network applications and other software. 
     The network testing system  110  may be in the form of a chassis or card rack, as shown in  FIG. 1 , or may be an integrated unit. Alternatively, the network testing system may comprise a number of separate units such as two or more chassis cooperating to provide network analysis, network conformance testing, and other tasks. The chassis of the network testing system  110  may include one or more network cards  120  and a back plane  112 . The network cards  120  may be coupled with back plane  112 . One or more network cards  120  may be included in network testing system  110 . The network cards  120  may be permanently installed in the network testing system  110 , may be removable, or may be a combination thereof. 
     The network testing system  110  and/or one or more of the network cards  120  may include an operating system such as, for example, versions of Linux, Unix and Microsoft Windows. 
     Network card  120  is coupled with network  140  via a communications medium  144 . Although a single connection over communications medium  144  is shown, each of the network cards  120  may be connected with network  140  over a communications medium. In one embodiment, the network cards may have two or more connections each over a communications medium with the network  140  and/or with multiple networks. The communications medium may be, for example, wire lines such as an Ethernet cable, fibre optic cable, and coaxial cable, and may be wireless. 
     The network testing system  110  and the network cards  120  may support one or more well known higher level (OSI Layers 3-7) communications standards or protocols such as, for example, one or more versions of the User Datagram Protocol (UDP), Transmission Control Protocol (TCP), Internet Protocol (IP), Internet Control Message Protocol (ICMP), Internet Group Management Protocol (IGMP), Stream Control Transmission Protocol (SCTP), Session Initiation Protocol (SIP), Hypertext Transfer Protocol (HTTP), Address Resolution Protocol (ARP), Reverse Address Resolution Protocol (RARP), File Transfer Protocol (FTP), Real-time Transport Protocol (RTP), Real-time Transport Control Protocol (RTCP), Real-Time Streaming Protocol (RTSP), the Media Gateway Control Protocol (MEGACO), the Session Description Protocol (SDP), Border Gateway Protocol (BGP), Enhanced Interior Gateway Routing Protocol (EIGRP), Multiple Spanning Tree Protocol (MSTP), Open Shortest Path First (OSPF), Protocol-Independent Multicast-Sparse Mode (PIM-SM), Intermediate System to Intermediate System (IS-IS or ISIS), Per-VLAN Spanning Tree Plus (PVST+), Rapid Per-VLAN Spanning Tree Plus (RPVST+), and Simple Mail Transfer Protocol (SMTP); may support one or more well known lower level communications standards or protocols (OSI Layers 1-2) such as, for example, the 10 and/or 40 Gigabit Ethernet standards, the Fibre Channel standards, one or more varieties of the IEEE 802 Ethernet standards, Asynchronous Transfer Mode (ATM), X.25, Integrated Services Digital Network (ISDN), token ring, frame relay, Point to Point Protocol (PPP), Fiber Distributed Data Interface (FDDI), Universal Serial Bus (USB), IEEE 1394 (also known as i.link® and Firewire®); may support proprietary protocols; and may support other protocols. Each network card  120  may support a single communications protocol, may support a number of related protocols, or may support a number or combination of related or unrelated protocols. 
     The term “network card” as used herein encompasses line cards, test cards, analysis cards, network line cards, load modules, interface cards, network interface cards, data interface cards, packet engine cards, service cards, smart cards, switch cards, relay access cards, CPU cards, port cards, and others. 
     The network cards  120  may include one or more processors  124  and one or more network communications units  128 . In another embodiment, the network cards  120  may have no processors  124  and may include one or more network communications units  128 . In the embodiment in which the network cards do not include a processor, processing may be performed by a processor on a motherboard of the network testing system  110 , on another card, on the backplane or by a remote or external unit. When the network card  120  includes two or more network communications units  128 , the network card  120  is in effect two or more network devices. That is, a network card  120  having n network communications units  128  may function as n network devices. 
     The network communications unit  128  may be implemented as one or more field programmable gate arrays (FPGA), application specific integrated circuits (ASIC), programmable logic devices (PLD), programmable logic arrays (PLA), other kinds of devices, and combinations of these. The network communications unit  128  may support one or more communications protocols. The network communications unit  128  may include a network interface through which the network card  120  may transmit and/or receive communications over the network  140 . 
     The network card  120  may include and/or have access to local and/or remote memory, storage media and storage devices. Instructions to be executed by the processor  124  may be stored on and executed from a local or remote computer readable storage medium or storage device. A computer readable medium includes, for example, without limitation, magnetic media (e.g., hard disks, tape, floppy disks), optical media (e.g., CD, DVD, BLU-RAY DISCO), flash memory products (e.g., MEMORY STICK®, COMPACTFLASH® and other flash memory media), and volatile and non-volatile silicon memory products (e.g., random access memory (RAM), programmable read-only memory (PROM), electronically erasable programmable read-only memory (EEPROM), and others). A storage device is a device that allows for the reading from and/or writing to a storage medium. Storage devices include hard disk drives, magnetic tape, solid-state drives (SSDs), DVD drives, BLU-RAY DISC® drives, flash memory devices, and others. 
     The processor  124 , network communications unit  128 , and memory may be included in one or more FPGAs, PLAs, PLDs on the network card  120 . Additional and fewer units, hardware and firmware may be included in the network card  120 . 
     The back plane  112  may serve as a bus or communications medium for the network cards  120 . The back plane  112  may also provide power to the network cards  120 . 
     The network testing system  110  may have a computer (not shown) coupled thereto. The computer may be local to or remote from the network testing system  110 . The network testing system  110  may have coupled therewith a display  118  and user input devices such as a keyboard  114  and a mouse  116 , as well as other user input devices including, for example, pens and trackballs. The user input devices may be coupled to a network card, other card, motherboard, or backplane included in the chassis. 
     The network testing system  110  may be implemented in a computer such as a personal computer, server, or workstation, as well as the chassis shown. The network testing system  110  may be used alone or in conjunction with one or more other network testing systems  110 . The network testing system  110  may be located physically adjacent to and/or remote to the network devices  130  in the network  140 . The network testing system  110  may be used to test and evaluate the network  140  and/or portions thereof, network devices  130 , applications running on network devices  130 , and/or services provided by network  140  and/or network devices  130  and/or network applications. The network testing system  110 , the network cards  120 , and the network communications units  128  may all be network devices. 
     The network  140  may be a local area network (LAN), a wide area network (WAN), a storage area network (SAN), or a combination of these. The network  140  may be wired, wireless, or a combination of these. The network  140  may include or be the Internet. The network  140  may be public or private, may be a segregated test network, and may be a combination of these. The network  140  may be comprised of a single or numerous nodes providing numerous physical and logical paths for packets to travel. Each node may be a network device as described herein. A node may be a computing device, a data communications device, a network device, a network card, or other devices as defined and described herein. 
     Communications on the network  140  may take various forms, including frames, cells, datagrams, packets, messages, higher level logical groupings, or other units of information, all of which are referred to herein as packets. Those packets that are communicated over a network are referred to herein as network traffic. The network traffic may include packets that represent electronic mail messages, streaming media such as music (audio) and video, telephone (voice) conversations, web pages, graphics, documents, and others. 
     The network devices  130  may be devices capable of communicating over the network  140  and/or listening to, injecting, delaying, dropping, relaying, processing, and/or modifying network traffic on network  140 . The network devices  130  may be computing devices such as computer workstations, personal computers, servers, portable computers, set-top boxes, video game systems, media players such as BLU-RAY DISC® players, personal video recorders, telephones, personal digital assistants (PDAs), computing tablets, and the like; peripheral devices such as printers, scanners, facsimile machines and the like; network capable storage devices including disk drives such as network attached storage (NAS) and SAN devices; testing equipment such as network analyzing devices, network conformance systems, emulation systems, network monitoring devices, and network traffic generators; components such as processors, network cards and network communications units; and networking devices such as routers, relays, firewalls, hubs, switches, bridges, traffic accelerators, and multiplexers. In addition, the network devices  130  may include home appliances such as refrigerators, washing machines, and the like as well as residential or commercial heating, ventilation, and air conditioning (HVAC) systems, alarm systems, may also include point of sale systems and bank teller machines, and other devices or systems capable of communicating over a network. One or more of the network devices  130  may be devices to be tested and may be referred to as devices or systems under test. 
     The network testing system  110  may send communications over the network  140  to a or through a network device  130 . The destination of communications sent by the network testing system  110  may be a device under test such as a network device  130 , may be the network testing system  110  such as a test between two network cards in the same network testing system  110 , and may be a second network testing system  111 . The network testing system  111  may be similar to or the same as network testing system  110 . A first network card  120  in the network testing system  110  may send communications over the network  140  to a or through a network device  130  that are received by a second network card  120  in the network testing system  110  or are received by a third network card in the network testing system  111 . A first network communications unit in a first network card in the first network testing system  110  may send communications over the network  140  to a second network testing system  111 , and a second network communications unit the first network card in the first network testing system  110  may receive communications over the network  140  from the second network testing system  111 . A first network communications unit in a first network card in the network testing system  110  may send communications over the network  140  and optionally through a network device  130  to a second network communications unit on the same network card in the same network testing system. The network testing system  110  may listen to and capture communications on the network  140 . 
     The methods described herein may be implemented on one or more FPGAs and/or other hardware devices, such as, for example, digital logic devices. The methods described herein may be implemented as software, namely network testing software, running on a network testing system and executed by a processor, such as a processor on a network card or a processor in a network testing system. The network testing software may be stored on a volatile or nonvolatile memory device or storage medium included in or on and/or coupled with a computing device, a network testing system, a network card, or other card. The methods may be implemented on one or more network cards  120  in a single network testing system or may be implemented on one or more network cards  120  on each of two or more network testing systems. 
     Network tests run on network testing system  110  may test the functionality and features of network devices  130  coupled with network  140  and of applications or other software running on servers or network devices  130  coupled with network  140 . In one embodiment, when testing the functionality and features of devices coupled with network  140 , a first network card  120  in network testing system  110  would perform certain actions recited in  FIG. 2  described below causing packets to be transmitted to a network device  130  (commonly referred to as a device under test or DUT) coupled with the network  140  and directed to, for example, the first or originating network card, to a second network card  120  or to a network card in another testing system coupled to the network. 
     In other embodiments, the testing environment shown in  FIG. 1  may be virtualized such that some of the hardware components are implemented virtually as software. 
     The network testing software may provide a graphical user interface that allows users to prepare network tests, view the results of network tests, monitor network traffic, and perform other actions. The network testing software may support or provide access to tests and analysis of network traffic according to a plurality of communications protocols, including higher level and/or lower level communications protocols. 
     Methods 
       FIG. 2  is a flow chart of actions taken to implement calls per second network testing. As preliminary action, a network testing software user interface is provided to allow a user to prepare a network test, as shown in block  210 . This is typically achieved after a user has started execution of network testing software on a network testing system or other computing device. Within the network testing software, the user may elect to prepare a network test. The network testing software provides the user the ability to select from multiple kinds of network tests, including a network test with Internet telephone calls based on the number of calls initiated per second, as shown in block  212 . Pertinent to the disclosure herein, the network testing software allows the user the ability to prepare a large volume of network calls and run tests involving VOIP calls and transmissions that typically involve SIP. The calls created according to the methods described herein are evenly distributed over a relatively short period or timeframe, such as for example, over a period of 1, 10, 100, etc. milliseconds or over a period of 1, 2, 4, 5, 10, etc. seconds. In one embodiment, the calls are evenly distributed every second. For example, to achieve an objective of 100 calls per second, a call is initiated each 10 milliseconds (system defined interval). In this example, any 10 millisecond timeframe that contains over 5 initiated calls is considered a burst. For an objective of 1000 calls per second, 50 initiated calls in a 10 millisecond timeframe is considered a burst. 
     The network testing software receives user selection to create a network test with bulk Internet telephone calls based on the number of calls initiated per second, as shown in block  214 . In response to receiving a user selection to create a network test with bulk Internet telephone calls based on the number of calls initiated per second as shown in block  214 , the network testing software prompts the user for and receives the user specification of the number of calls to be initiated every second as shown in block  216 . The calls initiated per second is one part of call transmission criteria, some of which are user specified and some of which are calculated by the network testing software. The network testing software then provides a user interface allowing a user to create a network test with bulk Internet telephone calls according to various call transmission criteria, as shown in block  218 . In one embodiment the actions of block  216  may be included in block  218  such that the call transmission criteria for a network test with bulk calls includes the number of calls to be initiated every second. 
     The criteria involved in testing a VOIP or other network calling system with a multitude of calls or bulk calls include the “talk time”, “number of channels”, “estimated overhead time” and the “minimum inter-call duration”. The talk time may be specified in milliseconds and refers to the duration between the moment a call is connected and the moment a call disconnect is initiated. When using SIP, the talk time may be computed as the time between [a] the time when an SIP ACK for an SIP INVITE is transmitted or the time when a first RTP packet is received, and [b] the time when an SIP BYE request message is sent. The number of channels is a whole number that that refers to the number of simulated voice channels to be used for achieving the desired testing rate. The estimated overhead time is computed in milliseconds by the network testing software and refers to the duration of other actions on the channel excluding the talk time and minimum inter-call duration. For example, in a typical call scenario, the estimated overhead time includes the sum of the call setup time, the call disconnect time, and any trigger operations. Triggers are used for call synchronization and are operations performed according to the applicable protocol at the occurrence of a specified event or events, or reaching a specified value or threshold. For example, in a testing environment, a trigger may be used to initiate a call disconnect after all RTP packets are sent and received by both caller and recipient. The minimum inter-call duration is computed in seconds by the network testing software and refers to the minimum time interval between the end of a call on a voice channel and the start of a new call on the same voice channel. As described in more detail below, in one embodiment, the network testing software computes the number of channels after the user enters the talk time, or the network testing software computes the talk time after the user specifies the number of channels. 
     The method described in  FIG. 2  may be better understood by reviewing the screen shot  300  displayed in  FIG. 3 . Referring now to  FIG. 3 , there is shown a screen shot  300  of a graphical user interface provided to a user to achieve calls per second network testing like that described regarding  FIG. 2 . The network testing software provides a user interface that may be menu driven, and may include pull down menus, text entry boxes, radio buttons, check boxes and other graphical user interface items. Among various kinds of network tests, the user may select to prepare a test of VOIP calls by selecting VoIPLink  302  (see block  214  of  FIG. 2 ). Associated with the VOIP test is a calls initiated per second objective  304 . The calls initiated per second objective is a user specified whole number. Typical calls initiated per second objective values include 10, 25, 100, 1000, and others. 
     Returning now to a discussion of  FIG. 2 , in response to receiving a user selection to create a network test with bulk Internet telephone calls based on the number of calls initiated per second as shown in block  214  and receiving the number of calls to be initiated every second as shown in block  216 , the network testing software provides a user interface allowing the user to specify criteria to create a network test with bulk Internet telephone calls, as shown in block  218 . The criteria may be presented a custom properties pane  310  shown in  FIG. 3 . The custom properties pane  310  may be provided when a user clicks on, taps on or otherwise selects the call initiated per second objective  304 . 
     Returning now to a discussion of  FIG. 2 , the network testing software provides the user the ability to select to enter information specifying the talk time or the number of channels, as shown in block  220 . The user selects to proceed by specifying either talk time  230  or number of channels  240 . In one embodiment, the user selects either talk time  230  or number of channels  240  by selecting a radio button such as radio buttons  330  and  340  shown in  FIG. 3 . Other ways of presenting this choice to the user and of receiving the user&#39;s selection may be used, including, check boxes, a slider, pull-down menu, and others. When the user elects to specify the talk time  230 , the network testing software, receives the user specified talk time, as shown in block  232 . This may be achieved by text entry field, pull down menu, or other user interface technique. The network testing software then calculates the number of voice channels based on the user (or system) specified number of calls per second and the user specified talk time, as shown in block  234 . Alternatively, when the user elects to specify the number of channels  240 , the network testing software, receives the user specified number of channels, as shown in block  242 . This may be achieved by text entry field, pull down menu, or other user interface technique. The network testing software then calculates the talk time based on the user (or system) specified number of calls per second and the user specified number of voice channels, as shown in block  244 . 
     After blocks  234  and  244 , the user may specify additional test parameters not pertinent to the discussion herein and elect to begin the network test. The network testing software receives user selection to begin the network test, as shown in block  250 . The network testing software begins transmitting packets for the network test, as shown in block  252 . To keep the calls initiated per second objective without over-exceeding it, the network testing software regularly recalculates the calls to be generated per channel at a system defined interval to avoid bursts of calls, as shown in block  254 . Bursts and over-transmission are kept near or to the user specified calls per second objective so as not to overflow or overwhelm the particular device under test that is the recipient of the calls (which may be another network testing system) or a pass-through of the call creation requests (such as, for example, a router, bridge, or switch). 
     In one embodiment, the network testing software attempts to keep the calls generated to not exceed a system defined or user specified threshold. The system defined or user specified threshold may be a percentage of the user specified call initiated per second objective. In one embodiment, the network testing software attempts to keep the calls generated to not exceed a system defined threshold of 102% of the user specified call initiated per second objective. In one embodiment, to keep the number of calls generated from creating an unintended burst, the system defined interval for recalculation is every 10 milliseconds. To maintain the precision of a 10 milliseconds timer in a single flow of execution (where all input/output events, state machine events and timer events are processed in a single flow), a lower level hardware signal may be used. The signal may be generated periodically at a 1 millisecond interval that updates a global timer. An event dispatching loop may check the global timer and preempts any activity gracefully so as to provide higher priority when required. 
     Referring now to the screen shot displayed in  FIG. 3 , in one embodiment, the user selects either talk time  230  or number of channels  240  by selecting a radio button such as radio buttons  330  and  340  shown in  FIG. 3 . When the user selects to specify the talk time  230  by selecting radio button  330 , the user enters the talk time in a text entry field  332  provided by the network testing software. Similarly, when the user selects the number of channels radio button  340 , the user enters the number of channels in a text entry field  342  provided by the network testing software. In this embodiment, when the user selects the specify talk time radio button  330 , the text entry field for the number of channels  342  is greyed out to signify that the number of channels will be system calculated based on the user specified talk time and the calls initiated per second objective value. Similarly, when the user selects the specify the number of channels radio button  340 , the text entry field for the specified talk time  332  is greyed out to signify that the talk time will be system calculated based on the user specified number of channels and the calls initiated per second objective value. When the user selects to specify the talk time (as shown in block  230 , and by radio button  330 ), the network testing software prepares and displays the calculated number of channels (as shown in block  234 ) and provides the calculated number of channels via the user interface  300  by, in one embodiment, a text label  344  and the actual value  346  in custom parameters pane  310 . 
     The user interface also allows the user to specify or the network testing software to display a system defined or computed default value for the estimated overhead time  350  and the maximum channel inter-call duration  360  in the bulk call generation settings pane  310 , both of which are part of the call transmission criteria. 
     The example depicted in  FIG. 3  shows a user or system specified calls per second objective  310  having a value  322  of 3,000 call per second. The examples shows the specify talk time radio button  330  selected with a user specified talk time value  332  of 69,000 milliseconds. Because the user elected the specify talk time radio button  330 , the specify number of channel radio button  340  is unselected, the number of channels value area  342  is greyed out, and a system computed number of channels value of 240,000 is provided in the number of channels value area  342 . In this example, the estimated time overhead  350  has a value of 10,000 milliseconds in the estimated overhead time value area  352 , and the minimum channel inter-call duration  360  has a value of 1,000 milliseconds in the minimum channel inter-call duration value area  362 . The calculated number of channels  344  is show in the calculated number of channels value area  346  as 240,000, which is also provided in the greyed out specify number of channel value area  342 . 
     Depending on the user specified network test and the configuration of the hardware devices in the specific test environment, the same network testing system that transmits packets may receive, process and analyze the packets sent in the network test. In some configurations, a second network testing system may receive the packets that initiated from a network test on a first network testing system. 
     Closing Comments 
     Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and procedures disclosed or claimed. Although many of the examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements may be combined in other ways to accomplish the same objectives. With regard to flowcharts, additional and fewer steps may be taken, and the steps as shown may be combined or further refined to achieve the methods described herein. Acts, elements and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments. 
     As used herein, “plurality” means two or more. 
     As used herein, a “set” of items may include one or more of such items. 
     As used herein, whether in the written description or the claims, the terms “comprising”, “including”, “carrying”, “having”, “containing”, “involving”, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of”, respectively, are closed or semi-closed transitional phrases with respect to claims. 
     Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. 
     As used herein, “and/or” means that the listed items are alternatives, but the alternatives also include any combination of the listed items.