# Patent

## Title
Optimized data stream upload

## Abstract

Systems and methods utilize a distributed server network to allow for the optimization of the upload of a data stream from a computing device. Performance metrics are estimated for different network paths from the computing device to a variety of entry servers in the distributed server network. Based on the estimated performance metrics, one or more entry servers are then selected to receive the data stream from the computing device. As a result, the systems and methods described herein allow for high quality upload performance which addresses the first mile vulnerability issues of the data stream. The distributed server network can then transmit copies of the data stream in real-time to other computing devices.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is continuation of and claims priority to U.S. patent application Ser. No. 12/850,136 filed Aug. 4, 2010, and set to issue as U.S. Pat. No. 9,137,163 on Sep. 15, 2015, the entire disclosure of which is incorporated herein by reference. The present application is also related to the following, the entire disclosures of which are hereby incorporated herein by reference: U.S. patent application Ser. No. 12/913,694 filed on Oct. 27, 2010, now U.S. Pat. No. 8,713,130 issued on Apr. 29, 2014; U.S. patent application Ser. No. 14/179,410 filed on Feb. 12, 2014, now U.S. Pat. No. 9,092,991 issued on Jul. 28, 2015; U.S. patent application Ser. No. 14/807,798 filed on Jul. 23, 2015; PCT application number PCT/US11/25533 filed on Feb. 18, 2011, now published as WO 2012/018411 on Feb. 9, 2012; and PCT application number PCT/US11/25545 filed on Feb. 18, 2011, now published as WO 2012/018412 on Feb. 9, 2012.


BACKGROUND
Field of Invention
The present invention generally relates to streaming multimedia data. More specifically, the present invention concerns managing the upload of a data stream such as a live video data stream from a computing device.
Description of Related Art
Examinations are used to determine the ability of an exam taker such as a student or prospective practitioner as it pertains to proficiency in a particular subject or skill set. For example, a student might take an exam to determine whether the student possesses requisite knowledge in a particular subject that might be related to receiving a degree or certificate. A prospective practitioner of law or medicine similarly might sit for an examination to determine their competence as it pertains to practicing in that profession.
Students or prospective practitioners have historically gathered at the designated locale for an examination on a proscribed date and time. Examination materials are then handed out by a testing authority and the exam begins. During the allotted time, the exam takers read questions and provide answers on a provided answer sheet or in a ‘blue book.’ Throughout the course of examination, a teacher or proctor keeps careful watch over the exam takers to ensure that no instances of cheating are taking place. While a single proctor may be able to observe a small group of exam takers, such observation becomes more difficult for a larger exam taking pool or for a group of exam takers utilizing laptop computers or other computing devices.
The increased popularity of distance learning has also complicated proctoring of examinations. The distance learning instructional model delivers education material and information to students who are not physically ‘on site’ at an education facility. Distance learning provides access to learning opportunities when the source of the information and the student are separated by time or distance if not both. Thousands of distance learners may be involved in a particular distance learning program or course at any given time.
Distance learning is no different than any other educational program in that there is a need to verify the qualifications of students through examination. Because distance learners are not collectively gathered at a physical learning institution such as a university, the distance learning program often requires that the students attend an examination center—which defeats a purpose of distance learning—or administers an examination online. An online examination is difficult to proctor as an exam taker could be taking an examination in one window of a web browser while looking up answers in another window via the Internet. An exam taker could also utilize a ‘chat’ or ‘messaging’ application to relay questions to and receive answers from a knowledgeable third-party. The value of online examinations is, therefore, questionable and calls into question the overall value of the corresponding class or degree program.
Techniques for remotely monitoring the visual and/or audio environment surrounding the exam taker, through the use of an environment capture device such as a video camera or other capture device, are disclosed in commonly-owned U.S. patent application Ser. No. 12/723,666, the disclosure of which is incorporated herein by reference. In order to ensure the integrity of the exam process, the real-time audio and/or video data streams of the testing environment can be provided over a network to a remote proctor who is responsible for remotely observing the administration of the exam.
Uploading the data stream and subsequently providing it in real-time to a remote proctor is challenging for a number of reasons including high bit rates, delay, and loss sensitivity. In particular, the data stream is vulnerable to upload restrictions and/or disruptions along the “first mile” from the test taker's computing device into the network, which can cause packet loss and delay of data in the data stream. This can be due to physical upload bandwidth limitations through the use of dial-up modems, or other upload restrictions such as network service provider limitations. As a result, the so-called ‘first mile’ can become a bottleneck, which can render further downstream techniques ineffective, since these downstream techniques cannot improve the bit rate and stream integrity of the initially uploaded data stream.
There is a need in the art for managing the upload of a data stream, which addresses first mile vulnerability issues.
SUMMARY OF THE CLAIMED INVENTION
In a first claimed embodiment, a method for managing entry of a data stream from a computing device into a distributed server network that includes several entry servers includes receiving at a first server from the computing device an entry server assignment request. The entry server assignment request includes metadata and requests to transmit the data stream into the distributed server network via a network. The metadata identifies a first geographic location of the computing device based on information input by a user of the computing device and a second geographic location of the computing device based on an IP address of the computing device. The entry server assignment request is analyzed to select an entry server from the one or more servers of the entry servers to receive the data stream. The entry server is selected based on a several estimated performance metrics for a network path from the computing device to the entry server. The performance metrics are estimated based on the first geographic location and the second geographic location identified in the metadata. The entry server assignment data is transmitted from the first server to the computing device in response to the entry server assignment request. The entry server assignment data requests that the computing device transmit data in the data stream to the selected entry server.
In a second claimed embodiment, a non-transitory computer-readable storage medium has a computer program embodied on the medium. The computer program is executable by a processor to perform a method for managing entry of a data stream from a computing device into a distributed server network that includes several entry servers. An entry server assignment request is received at a first server from the computing device. The entry server assignment request includes metadata and requests to transmit the data stream into the distributed server network via a network. The metadata identifies a first geographic location of the computing device based on information input by a user of the computing device and a second geographic location of the computing device based on an IP address of the computing device. The entry server assignment request is analyzed to select an entry server from the one or more servers of the entry servers to receive the data stream. The entry server is selected based on a several estimated performance metrics for a network path from the computing device to the entry server. The performance metrics are estimated based on the first geographic location and the second geographic location identified in the metadata. The entry server assignment data is transmitted from the first server to the computing device in response to the entry server assignment request. The entry server assignment data requests that the computing device transmit data in the data stream to the selected entry server.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a system for providing optimization of entry of a data stream into a distributed server network.
FIG. 2 illustrates a method for implementing an online proctored examination.
FIG. 3 illustrates a method for uploading a data stream of the examination environment surrounding the exam taker during an online proctored examination.
FIG. 4 is illustrates a method for selecting an entry server to receive an encoded data stream.
FIG. 5 illustrates a method for transmitting an uploaded data stream of an examination environment to a proctor during an online proctored examination.
FIG. 6 illustrates a first interface that may be utilized in proctoring an online examination.
FIG. 7 illustrates a second interface that may be utilized in proctoring an online examination upon detecting aberrant behavior in the interface of FIG. 6.



DETAILED DESCRIPTION
A distributed server network that allows for the optimization of the upload of a data stream from a computing device is described herein. Performance metrics are estimated for different network paths from the computing device to a variety of entry servers in the distributed server network. Based on the estimated performance metrics, one or more entry servers are then selected to receive the data stream from the computing device. As a result, the systems and methods described herein allow for high quality upload performance which addresses the first mile vulnerability issues of the data stream. The distributed server network can then transmit copies of the data stream in real-time to other computing devices.
Based on the estimated performance metrics, the one or more entry servers are selected as the “optimum” entry point or points into the distributed server network for the data stream. The criteria for the selection of the “optimum” entry server or servers can vary. The criteria may, for example, be based on minimizing delay and/or packet loss of the data stream into the distributed server network. Other criteria such as upload bandwidth may also be used.
A video camera device or other visual and/or audio environment capture device may be used to generate a data stream of the examination environment surrounding the taker of an online examination. This data stream is encoded and uploaded into the distributed server network. The distributed server network can then transmit copies of the data stream for display on the computing device of a remote proctor during the administration of the examination. The proctor may view the data stream in real-time, and determine if any visual or audio activity in the examination environment constitutes activity not in accordance with the exam protocol.
FIG. 1 illustrates a system 100 for providing optimization of entry of a data stream into a distributed server network such as a content delivery network (CDN) 162. The system 100 of FIG. 1 includes computing devices 110, 112, 114 that may be utilized by a user (exam taker) to take an examination, CDN 162 for administering an examination and for routing exam data including real-time data streams via a communications network 150, a central office proctoring center 180, and geographically distributed proctoring centers 190, 192, 194.
The computing devices 110, 112, 114 may be any sort of computing device as is known in the art. The computing devices 110, 112, 114 include memory for storage of data and software applications, a processor for accessing data and executing applications, and input and output devices that allow for user interaction. The computing devices 110, 112, 114 further include components that facilitate communication over the communications network 150 such as an RJ-45 connection for use in twisted pair based 10baseT networks or a wireless network interface card allowing for connection to a radio-based communication network (e.g., an 802.11 wireless network).
The computing devices 110, 112, 114 may be a general purpose computing device such as a desktop or laptop computer. The computing devices 110, 112, 114 may belong to a particular user rather than being a computing device dedicated to exam taking as might be found in a examination center. Thin client or netbook client devices may be implemented in the context of computing devices as might mobile computing devices such as smart phones.
Communication network 150 may be a local, proprietary network (e.g., an intranet) and/or may be a part of a larger wide-area network. The communication network 150 may be a local area network (LAN), which may be communicatively coupled to a wide area network (WAN) such as the Internet. The Internet is a broad network of interconnected computers and servers allowing for the transmission and exchange of Internet Protocol (IP) data between users connected through a network service provider. Examples of network service providers are the public switched telephone network, a cable service provider, a provider of digital subscriber line (DSL) services, or a satellite service provider. Communication network 150 allows for communication between the various components of system 100.
The computing device 110 is representative of the computing devices 110, 112, 114. As described below, a video camera device 120 or other visual and/or audio environment capture device is used to monitor the exam taking environment surrounding the user (exam taker) of the computing device 110 during administration of an examination. The video camera device 120 generates a real-time data stream of the exam taking environment. This data stream is encoded and uploaded by the computing device 110 into the CDN 162, which in turn can transmit the data stream in real-time to the central office proctoring center 180, and/or one or more geographically distributed proctoring centers 190, 192, 194. A proctor may then view the data stream via a streaming technique in real-time (i.e., during administration of the examination), and determine if any visual activity in the examination environment constitutes activity not in accordance with the exam protocol. The term “streaming” as used herein refers to the transmission of data in the data stream by the CDN 162 to the computing device of an end user such as proctor, without requiring that the data stream first be uploaded in its entirety to the CDN 162.
The CDN 162 is coupled to the communications network 150. The CDN includes a CDN data center 170 and a plurality of entry servers 160-1 to 160-6. In the system 100 illustrated in FIG. 1, six entry servers 160-1 to 160-6 are shown. Notwithstanding the six illustrated servers, the system 100 may include more of less entry servers.
The CDN data center 170 also manages the real-time upload and distribution of data streams of the examination environments from the computing devices 110, 112, 114, as well as the storing of the data streams for retrieval and playback in a non-streaming fashion. The CDN data center 170 includes an application server 172, database server 174, and media server 176. The application server 172, database server 174, and media server 176 are each a computing device and include memory, a processor for accessing data and executing applications, and components to facilitate communication over communications network 150. The application server 172 includes an upload optimization module 173 stored in memory and executed by a processor to invoke its corresponding functionality.
The upload optimization module 173 is executable to handle assignment requests from the computing devices 110, 112, 114 to upload data streams such as those captured by the environment capture devices during administration of an exam. These assignment requests are analyzed by the upload optimization module 173 to select one or more “optimum” entry servers in the plurality of entry servers 160-1 to 160-6. The “optimum” entry server or servers then serve as an entry point or points for the data stream into the CDN 162. The database server 174 stores entry server information such as data indicating the physical or network location of each of the entry servers 160-1 to 160-6. This information can then be used by the upload optimization module 173 to select the entry point or points for the data stream.
The upload optimization module 173 in the illustrated embodiment includes a rate allocation algorithm and a network/location proximity algorithm. The rate allocation algorithm is used to determine the sending rate or upload bandwidth from each the computing devices 110, 112, 114 to assist in minimizing packet loss in the uploaded data streams. The network/location proximity algorithm is used to determine the location of the computing devices 110, 112, 114 to assist in minimizing the probability of packets arriving late to the selected entry server. The upload optimization module 173 is described in further detail below with respect to FIGS. 3 and 4.
The application server 172 also operates as an origin server for the exam content during the administration and proctoring of an examination. The exam content includes the uploaded data streams.
The exam content may also include exam data such as the actual exam (e.g. prompts and questions) or other data concerning an exam, as well and answers to the questions provided by the exam takers during an examination. Registration information of the exam takers, such as a name or examination identification number as well as a password, may also be stored in the database server 174. Other registration information might include a geographic location or address provided by the exam taker via a graphical user interface.
Biometric information such as a visual image of the exam taker may also be stored in the database server 174 and compared against a previously stored and known ‘good’ image of the exam taker. A similar comparison may be made with respect to a voice print. Retinal scans and finger prints, subject to the presence of the appropriate peripheral device, may also be stored and used for verifying exam taker identity. These peripheral devices may be implemented in the context of the use of video camera device 120, microphone 130, or other environment capture device.
The media server 176 handles the requests for the non real-time playback of the uploaded data streams, which may be stored in the database server 174 as well as the entry servers 160-1 to 160-6.
The entry servers 160-1 to 160-6, in conjunction with the application server 172 and database server 174, provide high-performance upload and delivery of the exam content to the exam takers and the proctors.
Each of the entry servers 160-1 to 160-6 is a computing device which includes memory, a processor for accessing data and executing applications, and components to facilitate communication over communications network 150. The application server 172 handles the distribution of copies of the exam content to the entry servers 160-1 to 160-6. The exam content can then be stored and transmitted to the exam takers and proctors by way of the entry servers 160-1 to 160-6 using a variety of different load balancing techniques, instead of being transmitted directly by the application server 172. The distribution of the exam content to the entry servers 160-1 to 160-6 may include on-demand or push-based mechanisms that move the exam content from the database server 174 to the entry servers 160-1 to 160-6. In addition, the distribution of the uploaded data streams may consist of on-demand or push-based mechanisms that move the uploaded data streams between entry servers 160-1 to 160-6, without requiring that the uploaded data stream first enter the CDN data center 170.
The entry servers 160-1 to 160-6 are arranged at various physically remote locations or regions. For example, entry server 160-1 may be located in North America, entry server 160-2 may be located in Asia, and entry server 160-3 may be located in Europe. The entry servers 160-1 to 160-6 may be arranged at the “edge” of the communication network 150 so that the entry servers 160-1 to 160-6 can be located physically close to the exam takers and proctors. Due to this physical proximity, the entry servers 160-1 to 160-6 can provide faster, higher quality data transmissions to achieve better load balancing, lower latency, and higher throughput in delivering the data streams than may be otherwise achieved using solely the application server 172.
Central office proctoring center 180 is an operations center with computing devices staffed with one or more proctors observing the data streams of various examination environments for exam takers at one or more examination sites. These examination sites may be physically remote from the central office proctoring center 180. Examination sites can be examination centers dedicated to the offering of examinations, traditional classroom settings, as well as personal space such as a home or office workspace. The geographically distributed proctoring centers 190, 192, 194 include computing devices which may belong to a particular proctor, rather than being a computing device dedicated to proctoring as might otherwise be found in the central office proctoring center 180. The proctors at the central office proctoring center 180 and geographically distributed proctoring centers 190, 192, 194 may observe and analyze a variety of different types of information to help ensure the integrity of the examination. The observation and analysis of information is described in further detail below with respect to secure testing application 140 and video camera device 120.
The computing devices 110, 112, 114 are secured in order to prevent access to files or other types of data such as notes, outlines, and exam preparation material during an examination, as well as preventing access to applications that themselves allow for access to data. The computing devices 110, 112, 114 may be secured for the taking of an exam as described in co-pending U.S. patent application Ser. No. 12/571,666, the disclosure of which has been previously incorporated by reference.
The computing device 110, 112, 114 may be secured through the download and subsequent installation of a secure testing application (e.g., secure testing application 140 installed on computing device 110). Secure testing application 140 may be downloaded from application server 172 or another computing device coupled to communications network 150. Secure testing application 140 may also be installed from a computer-readable storage device such as a CD-ROM. The secure testing application 140 may then be stored in memory at the corresponding computing device 110 and executed by a processor to invoke its corresponding functionality.
Secure testing application 140 is a security application software that prevents computing device 110 from accessing certain data or applications that might otherwise be in violation of examination regulations or protocols as identified by application server 172. The security application software 140 causes the computing device 110 to operate in a secure mode by introducing certain changes to the system registry such that only those applications or files deemed necessary or appropriate by the exam administrator and as embodied in a corresponding exam protocol may be allocated address space, loaded into memory and ultimately executed by the computing device 110.
For example, an exam protocol for a particular examination may deny access to a web browser, e-mail client, and chat applications such that an exam taker may not electronically communicate with other individuals during the examination. This particular protocol may be downloaded to the computing devices 110 from the CDN 162 along with exam data. The secure testing application 140 then operates in accordance with the downloaded testing protocol such that certain applications are not allowed to be loaded and executed.
Similar prohibitions or permissions may apply to hardware components of the computing device 110 as well as any number of hardware peripherals that might be introduced to the computing devices 110. Examples of such peripherals that might be introduced include a second computer monitor, docking stations, a traditional full-sized keyboard as might be used with a laptop computer. Other peripherals might include thumb drives, ‘time-shift’ recording devices that offer TiVo®-like functionality, as well as any number of other plug-and-play peripherals.
The secure testing application 140 may also operate in conjunction with the CDN 162 to properly execute an exam routine for the given examination event. For example, the exam routine may allow for the user to have access to all questions at any given time such that the user may answer and not answer questions at their leisure and subsequently return to any questions at a later time for further review. The exam routine may alternatively require the exam taker to lock in an answer or set of answers and have the same reported to the CDN 162 prior to receiving a subsequent question.
The secure testing application 140 may also observe activity on the computing device 110 during administration of an examination. If an exam taker attempts to make changes to the system registry that were implemented by the secure testing application 140, the secure testing application 140 may identify and report these attempts to the central office monitoring center 180, and distributed proctor monitoring centers 190, 192, 194.
The secure testing application 140 operates in conjunction with video camera device 120 or other visual and/or audio capture device to monitor the exam environment surrounding the exam taker of the computing device 110. Video camera device 120, which may be a commercially available web camera or other image acquisition device, generates a real-time data stream of the exam environment. If the exam taker leaves their seat or another individual enters the exam area during the course of the examination, the video camera device 120 will capture this visual information. The video camera device 120 provides the data stream to the secure testing application 140. As described in more detail below, the secure testing application 140 encodes and uploads the captured data stream into the CDN 162. The CDN 162 in turn delivers the data stream to the central office monitoring center 180, and/or one or more geographically distributed proctor monitoring centers 190, 192, 194, during the administration of the examination.
A proctor at the central office monitoring center 180 and/or the proctor monitoring centers 190, 192, 194 may then view the data stream provided by the CDN 162 and determine if any visual activity constitutes activity not in accordance with the exam protocol. The proctor may then log the information for further assessment by the actual exam administrator (e.g., the professor or professional association administrating the examination) or make a direct inquiry of the exam taker as to the nature of the observed behavior, and/or provide a warning as to terminate that behavior. Other external devices may also be used to gather environment data that can be provided in the encoded data stream uploaded to the CDN 172, such as a microphone 130 or other environment capture device.
FIG. 2 illustrates a method for implementing an online proctored examination. In step 210, an account is created by an exam taker. In step 220, an exam taker registers for and/or schedules an examination. In step 230, an exam taker engages in biometric enrollment and authentication. In step 240 the exam is delivered and proctoring commences at step 250. The aforementioned steps may be carried out as described in co-pending U.S. patent application Ser. No. 12/723,667 entitled “Secure Online Testing,” the disclosure of which is incorporated herein by reference.
Proctoring step 250 takes place over the course of the examination and may be implemented as part of step 240. The proctoring step 250 utilizes a variety of security technologies and processes to deter and detect aberrance during the exam process. In particular, the exam taking environment surrounding the exam taker is monitored in real-time by a proctor utilizing a live video feed of the exam taker. The live video feed is captured utilizing a video camera device or other visual and/or audio environment capture device, and uploaded in real-time to the CDN 162 utilizing the techniques described herein.
FIG. 3 illustrates a method 300 for uploading a data stream of the examination environment surrounding the exam taker during an online proctored examination. At step 305, the computing device 110 transmits an assignment request to the application server 172. The assignment request is a request for identification information of an entry server of the entry servers 160-1 to 160-6, which will serve as the entry point for the data stream into the CDN 162. The transmission of the assignment request may be initiated automatically by the secure testing application 140 upon successful completion of the enrollment and authentication of the exam taker. The assignment request will be describe in more detail with respect to FIG. 4.
At step 310, the application server 172 receives the assignment request. At step 315 the assignment request is analyzed to select an entry server of the entry servers 160-1 to 160-6, which will be entry point for the data stream. This determination is made based on one or more estimated performance metrics for a network path from the computing device 110 to the selected entry server of the entry servers 160-1 to 160-6. The performance metrics can be computed using an estimated physical location of the computing device 110, as well as entry server information such as the physical location of each of the entry servers 160-1 to 160-6 stored in the database server 174. The analysis of the assignment request and the selection of the particular entry server in step 315 are described in further detail below with respect to FIG. 4.
An assignment request may include data representing a second geographic location specified by a user of the computing device. Selection of the entry server may be further based on the second geographic location.
At step 320, the application server 172 transmits assignment data to the computing device 110 requesting that the computing device 110 upload the data stream to the selected entry server. The assignment data may include data representing an IP address of the selected entry server, or other unique identifying information of the selected entry server which can be used to facilitate connection between the computing device 110 and the selected entry server.
At step 325, the computing device 110 receives the assignment data. At step 330, the secure testing application 140 launches the examination on the computing device 110. The secure testing application 140 may then provide the exam taker with instructions concerning the positioning of the video camera device 120 or other visual and/or audio environment capture device. Alternatively, this process may be undertaken at the enrollment and authentication stage.
The video camera device 120 operates in conjunction with the secure testing application 400 to generate a real-time data stream of the examination environment. This data stream is provided to secure testing application 140, which in turn encodes the data stream into an encoded data stream. The data stream is encoded in a format dependent upon the application, and in the illustrated embodiment is encoded as defined by the well-known H.264/AVC standard. The encoded data stream includes not only the image and audio data itself, but also the information to enable a decoder to decode the data stream, and information about the structure of the encoded data and the compression tools used during encoding. These streams may be referred to as “bitstreams,” but the units of the encoded data stream in various embodiments can be bits, bytes, picture fields, frames, or any other unit that is appropriate for the embodiment.
At step 335, the computing device 110 transmits the encoded data stream in real-time to the selected entry server using the assignment data received at step 325. The selected entry server acts as the entry point for the encoded data stream into the CDN 162, and receives the data in the encoded data stream at step 340. The CDN 162 can then in turn transmit copies of the encoded data stream in real-time to the central office proctoring center 180, and/or one or more geographically distributed proctoring centers 190, 192, 194, during the administration of the examination. A proctor may then view the data stream via a streaming technique, and determine if any visual activity in the examination environment constitutes activity not in accordance with the exam protocol.
FIG. 4 is a method for selecting an entry server to receive the encoded data stream. At step 400, the assignment request is analyzed to determine the geographic location of the computing device 110. In the illustrated embodiment, the geographic location of the computing device 110 is determined by inspecting the IP address of the computing device 110 which is included in the assignment request. In alternative embodiments, other techniques for determining the geographic location of the computing device 110 may be used. For example, metadata in the assignment request may include the geographic location or address provided by the exam taker during registration or verification stages, or other metadata which can be used to identify the location of the computing device. In some embodiments, the geographic location or address of the computing device 110 may be determined utilizing the address information provided by the corresponding exam taker, which may for example be stored in the database server 174. As described above, this address information may be provided by the exam taker during the registration or verification stages. Alternatively, the exam taker may be prompted to provide such information prior to the launch of the examination.
At step 405, a set of one or more entry servers of the entry servers 160-1 to 160-6 are identified as possible entry points for the encoded data stream into the CDN 162. These identified entry servers may be a subset of the entry servers 160-1 to 160-6, which may be selected based on proximity to the determined geographic location of the computing device 110. For example, if it is determined that the computing device 110 is located in San Francisco, Calif., the set of entry servers may be those which are closest to San Francisco, Calif.
At step 410, expected performance metrics for different network paths from the computing device 110 to each of the identified entry servers are calculated. For example, if the set includes entry servers 160-1, 160-2 and 160-3, then the network paths from the computing device 110 through the network 150 to each of the entry servers 160-1, 160-2 and 160-3 are evaluated. These expected performance metrics may include bandwidth, packet loss, and delay for each of the various network paths. In some embodiments, these expected performance metrics are estimated without requiring an analysis of the actual performance metrics of the network paths. In such a case, relative values of the expected performance metrics may be determined by comparing the geographic location of the computing device 110 to the geographic and/or network locations of the identified entry servers. For example, the network path for the geographically closest entry server may be assigned the lowest estimated delay value. Alternatively, the actual performance metrics of the networks may be collected and analyzed.
At step 415, the performance metrics for the set of identified entry servers are compared to one another. The selected entry server to act as the entry point for the encoded data stream is then selected from the set based on this comparison. This selected entry server is selected as the “optimum” entry point into the CDN 162 for the encoded data stream, to allow for an optimal first mile experience for the data stream. The criteria for the selection of the “optimum” entry server can vary from embodiment to embodiment. The criteria may, for example, be performed by weighting each of the expected performance metrics for a given network path, and selecting the entry server based on comparison of the weighted results. The criteria may, for example, be based on minimizing delay and/or packet loss of the uploaded data stream into the CDN 162. Other and/or additional criteria such as upload bandwidth may also or alternatively be used.
The selection of the particular entry server may be based for example on which of the entry servers 160-1 to 160-6 is the closest to the computing device 110 in terms of network proximity. Network proximity may for example be represented by the delay or number of handoffs for the different network paths from the computing device 110 to each entry server of the set. In such a case, the selected entry server may correspond to the network path with the least number of handoffs.
The selection of the entry server may alternatively be based for example on which of the entry servers 160-1 to 160-6 is closest to the computing device 110 in terms of physical proximity. In such a case, the selected entry server may be the entry server which is geographically the closest to the computing device 110.
A backup entry server of the entry servers 160-1 to 160-6 may also be selected as an additional entry point for the data stream into the CDN 162. The backup entry server may be selected for example as the second most “optimum” entry point into the CDN 162, using the same criteria used to select the “optimum” entry point. In such a case, the assignment data transmitted to the computing device 110 by the application server 172 will further request that the computing device 110 also transmit the data stream to the selected backup entry server.
The utilization of the techniques for the optimization of the upload of a data stream as described herein provide for high data stream quality with low startup latency, as well ensuring network friendliness and upload fairness. In addition, the techniques can be implemented within existing CDN infrastructures.
FIG. 5 illustrates a method for transmitting an uploaded data stream of the examination environment to a proctor during an online proctored examination. At step 505, the application server 172 receives a request for a particular data stream. In the illustrated example, the request is during the administration of the examination and is from a computing device associated with a proctor. The computing device may be for example located in the central office proctoring center 180, or one or the geographically distributed proctoring centers 190, 192, 194.
In response to the request, at step 510 the application server 172 assigns an entry server in the entry servers 160-1 to 160-6 to transmit the data stream in a streaming fashion to the requesting computing device. The application server 172 may assign the entry server using load balancing techniques as known in the art. At step 515, the data stream is transmitted by the assigned entry server to the computing device associated with the proctor.
FIG. 6 illustrates an interface 600 that can be utilized in proctoring an online examination as might be observed on a computing device at the central office proctoring center 180. Interface 600 may allow for simultaneous observation of a number of data streams of the examination environment surrounding different exam takers. As shown in FIG. 6, the data stream of a single examination environment 610 is being observed from a total of twelve available examination environments 620. As illustrated in FIG. 6, the examination environment 610 being monitored exhibits aberrant behavior as reflected by alert 630. Aberrant behavior may be automatically detected, or generated in response to proctor input. FIG. 6 also illustrates a session ID 640, which is unique to the exam taker; a proctor identification 650, which identifies a proctor responsible for observing the examination session; as well as a start and end time 660 for the examination session. All of this information may be utilized in generating assessment data or logs following completion of the examination. In some instances, aberrant behavior may result in the data stream of the examination environment being ‘exploded’ into a larger view (like in FIG. 7) in the case where the proctor is responsible for monitoring a large number of exam takers.
Upon the exhibition of aberrant behavior as reflected by alert 630 in FIG. 6, the specific examination session may be singled out for further investigation through the interface 700 illustrated in FIG. 7.
FIG. 7 illustrates a second interface 700 that can be utilized in proctoring an online examination. The interface 700 may be launched in response to detecting aberrant behavior observed in the interface 600 of FIG. 6. The interface 700 of FIG. 7 (like that of interface 600 of FIG. 6) displays real-time video of the examination environment 610 of the exam taker. Recording of the video may take place upon detection of aberrant behavior for the purpose of validating or providing requisite evidence related to addressing disciplinary activity following an affirmative determination that an exam taker violated an exam taking protocol. In some instances the aberrant behavior may simply be that the examination environment needs to be modified to ensure proper proctoring, which could include raising the light level or decreasing background noise (e.g., closing a window). A proctor may provide this information to an exam taker.
The interface 700 of FIG. 7 also illustrates a current alert log 720 that identifies the specific aberrant behavior that lead to the automated alert 630 in the interface 600 of FIG. 6. The proctor may log the outcome of their determination related to the aberrant behavior in response log 730. Response log 730 allows a proctor to identify the particular behavior that was at issue (e.g., an audio problem or multiple people being present) (732) and the results of monitoring the aberrant behavior (734), which could include clearing the alert as a false alert, terminating the examination, or allowing the exam to continue. A proctor may also launch an on-demand verification of audio, visual, or keystroke analytics. Notes related to the incident may also be maintained in notes section 736 to further detail the specific incident. In some instances, the proctor may launch a live chat session with the exam taker while maintaining real-time observation.
The interface 700 may also maintain additional information such as a historical alert log 740 that maintains a running list of all aberrant behavior for the exam taker in question as well as security information 750, session information 760, and testing program information 770. Security information 750 may display specific information about an exam taker, including biometric information such as a photograph. Session information 760 may display information such as the name of the exam taker, the number of exam items answered, the number of breaks taken, and so forth as illustrated in FIG. 7. Information concerning specific protocols related to the examination may be identified in exam program information window 770.
Logging of aberrant behavior may be tied to audio and video feeds of the examination environment. In such instances, a proctor may simply log the unusual behavior but leave it to the exam assessment authority as to the ultimate disciplinary behavior. Providing audio and video context tied to the alert may be useful in this regard.
Computer-readable storage media refer to any non-transitory storage medium and that may allow for instructions to be provided to a central processing unit (CPU) for execution. Such media can take many forms, including, but not limited to, non-volatile and volatile media such as optical or magnetic disks and dynamic memory, respectively. Common forms computer-readable media include, for example, a floppy disk, a flexible disk, a hard disk, magnetic tape, any other magnetic medium, a CD-ROM disk, digital video disk (DVD), any other optical medium, RAM, PROM, EPROM, a FLASHEPROM, and any other memory chip or cartridge.
Computer-readable storage medium, which are non-transitory in nature, differ from the various forms of transmission media may be involved in carrying one or more sequences of one or more instructions to a CPU for execution. A bus carries the data to system RAM, from which a CPU retrieves and executes the instructions. The instructions received by system RAM can optionally be stored on a fixed disk either before or after execution by a CPU. Various forms of storage may likewise be implemented as well as the necessary network interfaces and network topologies to implement the same.
While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. The descriptions are not intended to limit the scope of the invention to the particular forms set forth herein. To the contrary, the present descriptions are intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

## Claims

1. A method for managing entry of a data stream from a computing device into a distributed server network having a plurality of entry servers, the method comprising:
receiving at a first server an entry server assignment request from the computing device, the entry server assignment request including metadata and requesting to transmit the data stream into the distributed server network via a network, the metadata identifying:
a first geographic location of the computing device based on information input by a user of the computing device, and
a second geographic location of the computing device based on an IP address of the computing device;

analyzing the entry server assignment request to select an entry server from the plurality of entry servers to receive the data stream, the entry server selected based on a plurality of estimated performance metrics for a network path from the computing device to the entry server, the plurality of performance metrics estimated based on the first geographic location and the second geographic location identified in the metadata; and
transmitting entry server assignment data from the first server to the computing device in response to the entry server assignment request, the entry server assignment data requesting that the computing device transmit data in the data stream to the selected entry server.

2. The method of claim 1, further comprising receiving data in the data stream at the entry server.

3. The method of claim 1, wherein the data stream is an audio data stream captured by an audio capture device.

4. The method of claim 1, wherein the data stream is a video data stream captured by a video recording device.

5. The method of claim 1, wherein the data stream is a video data stream of an environment surrounding a user of the computing device during administration of an examination on the computing device.

6. The method of claim 1, wherein the estimated performance metrics include one or more performance metrics selected from a group consisting of bandwidth, packet loss, and delay.

7. The method of claim 1, wherein the assignment data transmitted to the computing device includes data representing an IP address of the entry server.

8. The method of claim 5, wherein the distributed server network is a content delivery network.

9. The method of claim 8, further comprising transmitting the data stream to a second computing device during the entry of the data stream into the content delivery network.

10. The method of claim 9, wherein transmitting the data stream to the second computing device includes transmitting the video data stream for display on the second computing device during the administration of the examination.

11. A non-transitory computer-readable storage medium having a computer program embodied thereon, the computer program executable by a processor to perform a method for managing entry of a data stream from a computing device into a distributed server network having a plurality of entry servers, the method comprising:
receiving at a first server an entry server assignment request from the computing device, the entry server assignment request including metadata and requesting to transmit the data stream into the distributed server network via a network, the metadata identifying:
a first geographic location of the computing device based on information input by a user of the computing device, and
a second geographic location of the computing device based on an IP address of the computing device;

analyzing the entry server assignment request to select an entry server from the plurality of entry servers to receive the data stream, the entry server selected based on a plurality of estimated performance metrics for a network path from the computing device to the entry server, the plurality of performance metrics estimated based on the first geographic location and the second geographic location identified in the metadata; and
transmitting entry server assignment data from the first server to the computing device in response to the entry server assignment request, the entry server assignment data requesting that the computing device transmit data in the data stream to the selected entry server.

12. The non-transitory computer-readable storage medium of claim 11, wherein the method further comprises receiving data in the data stream at the entry server.

13. The non-transitory computer-readable storage medium of claim 11, wherein the data stream is an audio data stream captured by an audio capture device.

14. The non-transitory computer-readable storage medium of claim 11, wherein the data stream is a video data stream captured by a video recording device.

15. The non-transitory computer-readable storage medium of claim 11, wherein the data stream is a video data stream of an environment surrounding a user of the computing device during administration of an examination on the computing device.

16. The non-transitory computer-readable storage medium of claim 11, wherein the estimated performance metrics include one or more performance metrics selected from a group consisting of bandwidth, packet loss, and delay.

17. The non-transitory computer-readable storage medium of claim 11, wherein the assignment data transmitted to the computing device includes data representing an IP address of the entry server.

18. The non-transitory computer-readable storage medium of claim 15, wherein the distributed server network is a content delivery network.

19. The non-transitory computer-readable storage medium of claim 18, wherein the method further comprises transmitting the data stream to a second computing device during the entry of the data stream into the content delivery network.

20. The non-transitory computer-readable storage medium of claim 19, wherein transmitting the data stream to the second computing device includes transmitting the video data stream for display on the second computing device during the administration of the examination.