1. The first section examines common performance bottlenecks that need to be considered.

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1 OAKS Online Intrductin Oregn s OAKS Online is a cmputer-based adaptive test in which items are selected accrding t each student s ability. OAKS Online has incrprated a number f features and updates based n input frm Oregn teachers familiar with the system. OAKS Online is ffered t students up t three times per year in an eight-mnth testing windw, frm Octber 2009 thrugh May G t fr mre infrmatin abut OAKS Online. This dcument prvides netwrk administratrs with infrmatin, tls, and recmmended cnfiguratin details t help districts and/r schls prepare their netwrks fr peratinal testing. Objectives This dcument cntains three primary sectins: 1. The first sectin examines cmmn perfrmance bttlenecks that need t be cnsidered. 2. The secnd sectin recmmends tls t detect, analyze, and trublesht perfrmance bttlenecks. 3. The third sectin prvides specific netwrk cnfiguratin details that need t be met in rder t access the peratinal testing system. Cpyright 2009 American Institutes fr Research Updated 9/21/2009 Page 1

2 Apprved Web Brwsers (OAKS Online Applicatins) While students will take tests using AIR s secure brwser, OAKS Online applicatins (fr administratr use) are designed t wrk using the fllwing brwsers fr the crrespnding peratin systems: Operating System Versin Supprted Brwser Windws 98 Firefx 1.5 and 2.0; Internet Explrer Firefx 2.0 and higher; Internet Explrer 6; XP Firefx 2.0 and higher; Internet Explrer 6, 7 r 8 Vista Firefx 2.0 and higher; Internet Explrer 7 r 8 Mac OS Mzilla 1.3 Mac OS X 10.2 Firefx 1.5 and Firefx 2.0 and Firefx 2.0 and higher; Safari 2 and Firefx 2.0 and higher; Safari 3 Linux K12 LTSP Firefx 2.0 and higher Disable Pp-Up Blckers Pp-up blckers must be cmpletely disabled n Test Administratrs brwsers while accessing OAKS Online systems. This step is critical fr mnitring sessin/brwser activities and ensuring that TDS applicatins are prperly clsed. Netwrk Administratrs shuld effectively cmmunicate this t Test Administratrs and take additinal steps necessary t facilitate this prcess prir t testing. Secure Brwser All schls participating in OAKS Online must install the new secure brwser. The secure brwser is incmpatible with new enhancements and security features fr the OAKS Online test, and attempts t launch the secure brwser will nt cnnect t the OAKS Online test. In rder t avid cnfusin fr students and test administratrs, AIR strngly recmmends uninstalling the secure brwser befre installing the new brwser. Cpyright 2009 American Institutes fr Research Updated 9/21/2009 Page 2

3 Frbidden Applicatin Detectin A new feature built in t the secure brwser/oaks student interface autmatically detects certain applicatins that are frbidden t run while the secure brwser is pen and a student is either attempting t start r is in the prcess f taking a test. The secure brwser detects the applicatins currently running n a cmputer when it is launched. If a frbidden applicatin is detected (OAKS system maintains a list f prcesses deemed frbidden), the student is denied entry and receives a message indicating the pen applicatin. Similarly, if a frbidden applicatin launches while the student is already in a test (i.e. scheduled tasks), the student is lgged ut and a message is displayed. Befre administering tests, TAs shuld take prper measures t ensure that n frbidden applicatins are running n student cmputers. Netwrk administratrs are encuraged t reprt applicatins that culd have a negative affect n the functinality f the secure brwser. Fr example, a prgram running in the backgrund may have an autmatic update dialg that results in the taskbar/desktp being displayed. Depending n yur schl s netwrk plicy and resurces, administratrs might cnsider creating accunts specifically fr OAKS Online testing that limit access t certain applicatins. Thin Client Installatin Administratrs installing the secure brwsers ver a terminal server shuld take these steps t ensure that unique prfiles are created fr each instance where a secure brwser is launched. This will allw the system t detect frbidden applicatins n a terminal-basis rather than a netwrk-basis. Windws Terminal Server Installatin (Thin Client) Mzilla Firefx des nt allw fr mre than ne instance f the OAKS Secure Brwser t be pen when these instances are all written t the same prfile directry in 'Applicatin Data'. T crrect this: Create a batch file that runs in the Lgn Script (under the 'User Cnfiguratin') which cntains: "C:\Prgram Files\OAKSSecureBrwser3.0\kisk.exe" -CreatePrfile %SESSIONNAME% This creates a unique prfile flder in 'Applicatin Data' with a unique sessin name. This can be placed in the 'Startup' flder n the 'Start' menu (Start --> Prgrams --> Startup). Next, create a shrtcut n the Desktp f each client machine: "C:\Prgram Files\OAKSSecureBrwser3.0\kisk.exe" -P %SESSIONNAME% LTSP (Linux) Terminal Server Installatin (Thin Client) 1. An administratr shuld install the secure brwser in a flder that is available t all users, such as /pt. 2. Create shrtcuts n each user s desktp that pints t the secure brwser n /pt. 3. On a peridic basis (thrugh a crn jb), the administratr shuld run a script t delete the /hme/<user>/desktp/.oakssecurebrwser3.0/oakssecurebrwser3.0/* a. This step is t clear the prfiles that are created each time a Secure Brwser is launched frm a terminal. Cpyright 2009 American Institutes fr Research Updated 9/21/2009 Page 3

4 Cmmn Perfrmance Bttlenecks All netwrk cmmunicatins are accmplished using the IP prtcl suite. The LAN (lcal area netwrk) must be able t rute IP traffic t and frm the Internet. The testing system is delivered directly thrugh the Internet. Fr the testing t take place, all wrkstatins where tests will be administered must have Internet cnnectivity. In general, the perfrmance f the applicatin will depend n a number f factrs including: Ttal number f students taking the test at the same time As the number f students increases, there will be cmpetitin fr netwrk bandwidth bth n the internal netwrk and when ruting t the Internet. Netwrk bandwidth resembles highway traffic as the number f cars traveling n a given rad increases, the speed f traffic flw decreases. Size f the Test Cntent The size f the test is determined by tw factrs: 1) The number f items n the test; and 2) The average size f each item. The mre items a test cntains and the larger the average size f a test item, the higher the bandwidth requirement fr a given test will be. The number f items varies by test. The number f items per test during the schl year ranged between 45 and 60. The size f each item depends n the amunt f text and images the item cntains. Secure Brwser Installatin The recmmended installatin f the secure brwser is lcal installatin n each individual testing wrkstatin. It is pssible fr it t be installed n a netwrk/shared drive and then have the testing wrkstatins run the Secure Brwser frm that drive, but there will be sme perfrmance impacts under this cnfiguratin. There will be cmpetitin fr netwrk bandwidth, and the netwrk/shared disk drive will als be subject t sme resurce cmpetitin as there will be multiple clients reading frm the netwrk drive, thus slwing the verall prcessing speed. An examinatin f the varius installatin methds and advantages/disadvantages fr each setup is available n the OAKS Online prtal at Bandwidth Bandwidth is the amunt f data traveling acrss the netwrk at a given time. Bandwidth perfrmance can be affected n either f the fllwing netwrks: internal netwrk (LAN) traffic and/r Internet traffic frm the ruter. Regardless f hardware r netwrk tplgy, the LAN shuld be analyzed t determine the ptential fr traffic bttlenecks. Internal bandwidth is typically nt a prblem, as new switches generally perate between 100mpbs and 1000mbps. Hwever, LAN perfrmance can be hindered in cases where hubs are used instead f switches. A hub device will allw bradcast signals frm varius netwrk devices t prpagate acrss the netwrk, ptentially saturating the netwrk and causing traffic cmpetitin and/r cllisins f data. Cpyright 2009 American Institutes fr Research Updated 9/21/2009 Page 4

5 Fr Internet netwrks, the mst cmmn bttleneck is the ISP s ruter cnnectin which is typically anywhere frm 1.5mbps t 100mbps. Netwrk administratrs shuld spend time prir t test administratin determining if their Internet infrastructure has the capacity t accmmdate current and future grwth. Determining whether infrastructure is capable f current and future grwth invlves a number f steps, including but nt limited t: 1) The analysis f the current number f users; 2) current day-t-day Internet bandwidth statistics; and 3) the desired respnse time fr applicatins. Prxy Server Sme schls may use a prxy server. A prxy server is usually placed between the client and the Internet. Internet requests frm the client cmputer are frwarded thrugh the prxy server t the Internet. A prxy server implements a caching system t help imprve the respnsiveness f an Internet request by string a cpy f the web cntent lcally n the prxy server. Future requests frm a client are retrieved lcally frm the prxy server withut the need t retrieve data frm the Internet website yet again. This prcess can drastically help speed up future requests fr frequently used static cntent. Wireless Netwrk Over the past several years, there have been several revisins t wireless netwrking technlgy, including: n is the fastest and mst recent IEEE wireless standard, with a thrughput f up t 300mbit/s g has a theretical thrughput f up t 54mbit/s b has a theretical thrughput f 11mbit/s. Wireless Security Due t the sensitivity f test-related data, it is highly recmmended that wireless traffic use WAP2/AES data encryptin. Because encryptin/decryptin is part f the data exchange prcess, there may be a slight decrease in the verall speed f the netwrk. A prperly cnfigured wireless netwrk shuld prvide adequate bandwidth fr the testing applicatin. Cpyright 2009 American Institutes fr Research Updated 9/21/2009 Page 5

6 Netwrk Diagnstic Tls A perfrmance analysis f the LAN/Internet infrastructure is recmmended in rder t identify any bttlenecks that may impact test perfrmance. Identifying the diagnstic tl mst apprpriate fr a netwrk depends n the testing perating system, the netwrk administratr s knwledge-base, and the desired level f netwrk analysis. The Internet ffers a number f netwrk diagnstic tls, including but nt limited t the fllwing: Micrsft Windws Specific PRTG Traffic Grapher ( This Windws sftware mnitrs bandwidth usage and ther netwrk parameters via SNMP. It als cntains a built-in packet sniffer. Freeware versin available. NTttcp ( NTttcp is a multithreaded, asynchrnus applicatin that sends and receives data between tw r mre endpints and reprts the netwrk perfrmance fr the duratin f the transfer. Pathping Pathping is a netwrk utility included in the Windws perating system. It cmbines the functinality f Ping with that f Tracerute (Windws filename: tracert), by prviding details f the path between tw hsts and Ping-like statistics fr each nde in the path based n samples taken ver a time perid. Mac OS X Specific Netwrk Utility.app This is built int Mac OS X (10.3 r greater). Multi-Platfrm Wireshark ( Wireshark (frmerly Ethereal) is a netwrk prtcl analyzer. It has a large feature set and runs n mst cmputing platfrms including Windws, OS X, Linux, and UNIX. TCPDump ( TCPdump is a cmmn (UNIX, Linux, Mac OS X) packet sniffer that runs under the cmmand line. It allws the user t intercept and display TCP/IP and ther packets being transmitted r received ver a netwrk. A Windws prt Windump is als available ( Ping, NSLkup, Netstat, Tracerute (in Windws: tracert) This is a set f standard UNIX netwrk utilities. Versins f these utilities are included in all majr perating systems (UNIX, Linux, Windws, and Mac OS X). Iperf ( Iperf measures maximum TCP bandwidth, allwing the tuning f varius parameters and UDP characteristics. Iperf reprts bandwidth, delay jitter, and datagram lss. Cpyright 2009 American Institutes fr Research Updated 9/21/2009 Page 6

7 Netwrk Cnfiguratin Prtcls All cmmunicatin with the Test Delivery System takes place ver the fllwing IP prt/prtcl cmbinatins. Prt/Prtcl 80/tcp 443/tcp Purpse HTTP (Initial Cnnectin Only) HTTPS (Secure) Dmain Name Reslutin The fllwing URL s must be reslvable by all client hsts attempting t cnnect t the test system. This means that the client wrkstatins shuld be able t cnvert the friendly name (URL) belw t the IP address by requesting the infrmatin frm the DNS server. URL aks.tds.airast.rg akspt.tds.airast.rg Descriptin Brwser Installatin Files Operatinal Test Test Administratr Training/ Student Practice Test Firewall, Prxy Server and QS Firewall/Cntent Filter/Prxy Server Cntent filters, firewalls, and prxy servers shuld be cnfigured t allw traffic n the prtcls listed abve t the test delivery servers listed belw. In additin, sessin timeuts n prxy servers and ther devices shuld be set t values greater than the average duratin it takes a student t cmplete a given test. Fr mre infrmatin, cntact the AIR Help Desk (aks.helpdesk@air.rg). Schls will need t make sure infrmatin is nt blcked in their web filters and that data is nt cached. Please ensure the fllwing Prts and IP addresses are pen fr these TDS systems: IP Address URL Descriptin Brwser Installatin Files Operatinal Test TA Training / Student Practice Test QS/Traffic Shaping If the client netwrk utilizes any device(s) that perfrms traffic shaping, packet priritizatin, r Quality f Service, the abve IP addresses shuld be given a high level f pririty in rder t guarantee the highest level f perfrmance. Cpyright 2009 American Institutes fr Research Updated 9/21/2009 Page 7