Novavox Asterisk Card Installation Issues

PCICardCommonInstallationIssues

ReferenceNumber: NVXCPTBSH01Author: RichardSpencer

LastUpdated: 18May2008DocumentStatus: Issue

TechnicalSupport:ThisguideisfreelyavailabletoanyoneintheOpenSourceCommunitytohelpsolveconfigurationandinstallationissues.However,emailbasedtechnicalsupportisonlyavailabletocustomersthathavepurchasedOpenSourcetelephonyequipmentdirectlyfromNovavox.

Updates:DuetothenumberofalternativeOpenSourceIPPBXsoftwarepackagesavailableandnewversionsbeingregularlyreleased,itisdifficulttokeepOpenSourcedocumentationfullyuptodate.Ifyoufindanyoutofdateor inaccurateinformationwithinthisdocumentthenpleaseletusknowbyemailingusatfeedback@novavox.co.ukandwewillupdatethedocumentassoonaspossible.

Disclaimer: This document has been compiled based on experience resolving real worldcustomer configuration issues as well as information available within the Open Sourcecommunity. References to source material have not been included as it would make thedocument less easy to read. Also, keeping the references up to date would be very timeconsuming.However, if you discover information containedwithin this document forwhichyoubelieveyouaretheoriginalsourceandyouwouldliketoreceiveacknowledgement,thenpleaseletusknowandwewilladdtheappropriatereference.

NovavoxLimitedwww.novavox.co.ukRegisteredinEnglandNumber:06363978

Registeredoffice:2ndFloor,145157StJohnStreet,London,EC1V4PYVATRegistrationNumber:GB916422731

PCICardCommonInstallationIssues Page2of36

NovavoxLimited20072008

AboutNovavox

Novavoxhelpscreatereliable,affordable,integratedcommunicationsolutionstomeettheneedsofsmallbusinessesandmediumsizedenterprises.AnofficenetworkconnectedtotheInternetservesasthebasisfortheconvergenceofdata,voice,videoandmobilecommunicationsinasecure,integratedarchitecture.Withanintegratedcommunicationssolution,companiescansaveoncostlyphonebills,integratecustomerinformation,andhelpmakeemployeesmoremobilewithoutsacrificingcommunicationfunctionality.

Torealisethebenefitsthatintegratedcommunicationssolutionscanoffer,acompanyneedsanaffordable,reliablesolutiontailoredforthesmall/mediumofficeanddesignedforeaseofuse.NovavoxprovidesOpenSourcetelephonyequipmentspecificallydesignedforsmallbusinessesandmediumsizeenterprises.UsingOpenSourcesolutionsallowscompaniestobenefitfromprotectionagainstvendorlockinandabandonment,adramaticreductionincapitalexpenditurecostsandanendtoperuser/featurelicensingcosts.

Novavoxisdedicatedtosupplyingreliable,affordable,featurerichOpenSourcecomputertelephonyequipmenttosupportbusinessesupgradingexistingsystemsandthosedeployingnewsystems.WorkinginpartnershipwithNovavox,smallbusinessesandmediumsizedenterprisescandeployOpenSourcecommunicationsolutionstobenefitfromimmediatereturnoninvestment(ROI)throughdramaticallyreducedcallchargesandsignificantsavingsinequipmentandinfrastructurecosts.

ProductRange

NovavoxsuppliesarangeofalternativeOpenSourcetelephonyproductsincluding:

X100PSpecialEditionThebestofbreedsingleportFXOcardavailable OpenVox4portmodularanaloguePCIExpresscards OpenVox14portISDNBRIPCIcards OpenVox12portISDNPRI/E1/T1/J1PCIcards OctWareSoftEchocarriergradeechocancellationsoftwarelicences

Forfulldetailsofouralternativeproductspleasevisitourwebsitesproductsection:

www.novavox.co.uk/products

ContactDetails

ContactSales

Ifyourequireadditionalproductinformationorresellerpricinginformation,haveaninvoice/orderquery,orwouldliketorequestaquoteforacommunicationssolutiontomeetyourcompany'[email protected].

ContactSupport

Forassistancewithequipmentinstallationorforhelpwithadevice/serviceissuepleasevisitourwebsitesupportsectioninthefirstinstance:

www.novavox.co.uk/support

Novavoxcustomersonly:Ifafterfollowingtheguidanceprovidedonthesupportpageyouareunabletoresolvetheissuethenpleasecontactusatsupport@novavox.co.uk.



Contents

1 Introduction ................................................................................................42 CardNotDetectedbyMotherboard/Bios ...................................................52.1 ProblemDescription.................................................................................................. 52.2 Solution .................................................................................................................... 5

3 PCIBusIRQSharingIssues......................................................................63.1 ProblemDescription.................................................................................................. 63.2 Solution .................................................................................................................... 7

4 PCIBUSIRQMisses/Latency....................................................................84.1 ProblemDescription.................................................................................................. 84.2 Solution .................................................................................................................... 9

5 Echo.........................................................................................................145.1 ProblemDescription................................................................................................ 145.2 Solution .................................................................................................................. 15

6 FarendDisconnect ..................................................................................226.1 ProblemDescription................................................................................................ 226.2 Solution .................................................................................................................. 22

7 KernelPaniconReboot ...........................................................................247.1 ProblemDescription................................................................................................ 247.2 Solution .................................................................................................................. 24

8 QuickReference ......................................................................................269 FurtherAssistance ...................................................................................28AppendixASignallingmethods ...................................................................29AppendixBCountrycodes/zones..............................................................30AppendixCZaptel.confconfigurationparameters ......................................31AppendixDRecompilingZaptel...................................................................33AppendixEAcronyms.................................................................................36



1 Introduction

ThisdocumentdescribeshowtoovercomesomeofthemostcommonissuesexperiencedwheninstallingPCItelephonycardsinOpenSourceIPPBXsystems.SettingupanOpenSourceIPPBXforthefirsttimecanbeadauntingandsometimesfrustratingtask,particularlyifyouarenotfamiliarwithLinux.Thereisonlinehelpavailableintheformofforumsandwikis,andifyouencounteraproblemsomeoneelsehasprobablyhadthesameproblemandfoundasolution.However,searchingthroughtheforumsandwikisfortherelevantinformationandfindingasolutioncanbeverytimeconsuming.

Themainobjectiveofthedocumentistohelpmakecardinstallationaseasyaspossibleandtominimisetheamountoftimerequired.Themostcommonissuesarecoveredindepthanddetailedstepbystepsolutionsareprovidedalongwithbackgroundinformationexplainingthepurposeofeachstep.TheinformationprovidedfocusesonDigiumAsteriskandTrixboxbutcanbeusedtohelpinstallanOpenSourcetelephonycardinanyZaptel/AsteriskbasedIPPBXsystemincludingAsteriskNOW,ElastixandPBXinaFlash.

Disclaimer:Digium(www.digium.com)andAsterisk(www.asterisk.org)areregisteredtrademarksofDigium,Inc.Trixbox(www.trixbox.org)isaregisteredtrademarkofFonality,Inc.Elastix(www.elastix.org)isaregisteredofPaloSantoSolutions.NovavoxLimitedisnotaffiliatedwith,norendorsedbyanyofthecompanieslistedabove.



2 CardNotDetectedbyMotherboard/Bios

2.1 ProblemDescription

IfthecardyouhaveinstalleddoesnotappeartobelistedinanyshowcommandoutputsthenthefirststepistolookattheKernelsbootprocessmessagebuffer.Thebootprocessmessagebuffercanbeviewedusingthedmesg(diagnosticmessage)commandandwillshowifthecardhasbeendetectedbythemotherboard/bios:

#dmesg|more

Ifthecardhassuccessfullybeendetected,thedmesgoutputshouldshow:

...wcfxo:DAAmodeis'FCC'FoundaWildcardFXO:WildcardX100P...

TheaboveoutputisforanX100PSEcardbutsimilaroutputshouldbereceivedforothercards,e.g.FoundaWildcardTDM:WildcardTDM400PREVE/Ffor4portOpenVoxanaloguecards.

2.2 Solution

Ifyoucannotfindthelines fortherelevantcardinthedmesgoutput,then:

1. CheckthatthePCIslotsupportstherelevantstandard,mostcardsusePCI2.22. Checkthatcardhasbeeninsertedcorrectly,occasionallyithelpstopullthecard1

2mmoutoftheslotsothatitdoesnotgorighttothebottom3. TrymovingthecardtoadifferentPCIslot4. Tryanothercard(e.g.Networkcard)inthePCIslottofindouttocheckthatitisnot

faulty5. EnsuretheMotherboardhasthelatestBIOSinstalled

Thecardmustbedetectedbythemotherboard/biosbeforeyoucanproceedanyfurther.IfthecardisshowninthedmesgoutputbutisstillnotlistedinsomeoftherelevantshowcommandsthentheremaybeanIRQissueasdescribedinthefollowingsection.



3 PCIBusIRQSharingIssues


ThePeripheralComponentInterconnect(PCI)busprovidescommunicationbetweeninput/output(I/O)devicesandacomputer'sprocessor.InordertocommunicatewiththecomputerprocessoranI/Odevicemustsignalthatitwishestousethebusbysendinganinterruptrequest(IRQ).I/OdevicesareallocatedIRQbuslines/channels(commonlyreferredtoasIRQs)toallowthemtosignalaninterrupt,whichareidentifiedbyanindex.InthecaseofOpenSourceTelephonycards,thelineisanactualcontact(finger)onthecard,anditisacorrespondingpininthesocketsonthebusconnectedbyatraceonthemotherboard.Acardsendsaninterrupttothemotherboard'sinterruptcircuitrybychangingthevoltagelevelontheinterruptrequestline.ThisvoltagechangeactsviainterruptcontrollercircuitrytointerrupttheprocessortoservicethecardneedingtheCPU'sattention.

IftherearemoreI/OdevicesthantherearespareIRQsthentwoormoredevicescansharethesameIRQ.ForsomeI/Odevicesthisdoesnotcauseanyissues.However,theZapteldrivergenerates1000interruptsasecondforeachtelephonycardthatitcontrols.Iftheinterruptsarenothandledintimethenthiscancausesignificantissuesforaudiopassingthroughthetelephonycardsandcanevenpreventthecardsfromworkingaltogether.Forthisreason,itshouldbemadecertainthatcardsthatusetheZapteldriverliketheX100PSEhavetheirowndedicatedIRQtominimiseinterrupthandlinglatency.

WheninstallingaPCItelephonycardinanIPPBXforthefirsttime,ormovingittoadifferentslot,youmayreceivethefollowingerrormessage:

FailedtoinitailizeDAA,givingup...wcfxo:probeof0000:00:0c.0failedwitherror5

Todetermineifthecardhasbeendetected,usetheLinuxutilitylspciwhichdisplaysinformationaboutdevicesconnectedtothePCIbuswiththevoptiontocheckwhatIRQhasbeenallocatedbytheKernel:

#lspciv

IftheX100PSEcardhasbeendetectedsomethingsimilartothefollowinglinesshouldbeincludedintheoutput:

04:06.0Communicationcontroller:MotorolaWildcardX100PSubsystem:Unknowndeviceb100:0003

Flags:busmaster,mediumdevsel,latency32,IRQ217I/Oportsata800Memoryatdfafe000(32bit,nonprefetchable)Capabilities:[40]PowerManagementversion2

ThenextstepistoverifythattheX100PSEcardisrecognisedbytheLinuxKernelandthatitisusingitsallocatedIRQ.Thiscanbeachievedusingthefollowingcommand:

#cat/proc/interrupts

IfthecardisrecognisedandisbeinghandledcorrectlybytheZapteldriverthentheoutputshouldinclude:

7:25680730XTPICwcfxo



TheaboveoutputisfromasystemusingastandardXTProgrammableInterruptController(XTPIC).IfasystemisusinganAdvancedProgrammableInterruptController(APIC)thentheoutputwilllooklikethisinstead:

217:718680730IOAPIClevelwcfxo

Inbothcases,theZapteldriverforthecardmustbeallocateditsowndedicatedIRQ.

3.2 SolutionIfthecarddoesnthaveitsowndedicatedIRQ(listedin/proc/interrupts)then:

1. TrymovingthecardtoadifferentPCIslot2. Checkthatcardhasbeeninsertedcorrectly,occasionallyithelpstopullthecard1

2mmoutoftheslotsothatitdoesnotgorighttothebottom3. MakemoreIRQsavailablebydisablingallunnecessaryI/OdevicesintheBIOS,e.g.

serialports,parallelports,USB,etc.4. SeeifyoucanassignanIRQtoaspecificPCIslotintheBIOS(mostmodernbioses

don'tallowthisthough)5. Enable/disabletheplug'nplayOSoptionintheBIOS6. Enable/disableACPI(AdvancedConfigurationandPowerInterface)inthebiosorby

addingacpi=nointhegrubbootloader7. Enable/disableAPIC(AdvancedProgrammableInterruptController)inthebiosorbe

addingnoapicinthegrubbootloader8. Enable/disablehyperthreadingbyaddingnohtinthegrubbootloader9. Enable/disableSMP(SymmetricMultiProcessing)ondualcore/processIPPBXsin

thebiosorbyselectinganonsmpKernelfromthegrubbootloader10.Enable/disabletheirqbalancedaemon

Asstatedpreviously,OpenSourcetelephonycardsmusthavetheirowndedicatedIRQ(confirmedviacat/proc/interrupts)toavoidanyPCIinterruptrelatedissues.Itcansometimestakeawhile,butusingvariouscombinationsofthestepslistedaboveshouldeventuallyhelpprovideadedicatedIRQ.



4 PCIBUSIRQMisses/Latency


Asstatedintheprevioussection,theZapteldrivergenerates1000interruptsasecondforeachtelephonycardthatitcontrols.Iftheinterruptsarenothandledintimethenthiscancausesignificantissuesforaudiopassingthroughthetelephonycardsandcancauseclicks,pops,andglitches.ThemostimportantfunctionofanIPPBXsystemistoswitch/movedigitalsoundsamplesfromoneport/protocoltotheotheratveryconstantrate.Further,althoughlostaudiosamplesmaybetolerableforvoiceapplications,theymaybedetrimentaltodata/faxapplications.

IfyouexperienceaudioissuesandhaveconfirmedthatthecardhasitsowndedicatedIRQ(viacat/proc/interrupts)thentheremaybeamissinginterruptorinterruptlatencyissue.Aspreviouslystated,theZapteldrivergenerates1000interruptsasecondforeachtelephonycardthatitcontrols.Onewaytocheckthatthecorrectnumberofinterruptsarebeingreceivedistousethefollowingcommand:

#cat/proc/interruptssleep10cat/proc/interrupts

Theoutputshouldbesimilartotheoutputshownbelow:

CPU0217:1961653IOAPIClevelwcfxo...217:1971654IOAPIClevelwcfxo...

ThiscommanddisplaysthenumberofinterruptsforeachdeviceconnectedtothePCIbus,waits10secondsandthendisplaystheinformationagain.Ifwetake1961653from1971654theresultis10001.Asthetestisnotcompletelyaccurate1001isextremelyclosetotheexpected1000(i.e.1000persecond)sowecanseethatthecorrectnumberofinterruptsarebeingreceived.

Iftheoutputshowsthenumberofinterruptsas0oraverylownumberthenyouneedtocheckthattherelevantzaptelmodulesareloadedandthatthe/etc/zaptel.confand/etc/asterisk/zapata.conffilesareconfiguredcorrectly.

Anotherwayoftestingifthereisanissuewithmissinginterruptsistousethecommandzztoolwhichrunsatimingtest:

#zttest (stopwithctrl+c)

Theoutputshouldbesimilarto:

Openedpseudozapinterface,measuringaccuracy...99.995216%100.000000%99.995598%99.997948%99.996674%99.997070%99.996376%99.995995%99.999413%99.996780%99.996483%99.996483%99.996185%99.997078%99.996780%99.996674%99.996864%99.995125%99.999413%99.995895%99.997948%99.996689%99.996010%99.997459%99.997162%99.996971%99.996780%99.995995%99.997559%Resultsafter29passesBest:100.000Worst:99.995Average:99.996918,Difference:100.003041

Thehigherthepercentagethebetterthesoundsqualitywillbe.Iftheresultsare100%or99%thentheredefinitelyshouldntbeanymissingIRQrelatedissues.Iftheresultsare98%



thenthecardshouldworkOK,however,iftheresultsunder99.975%,thentherewillprobablybesomeaudioproblemsandthecardmaynotevenwork.

4.2 Solution

4.2.1 UpgradetoLinuxKernel2.6

TheLinuxkernelisresponsibleforcontrollingdiskaccessusingkernelI/Oscheduling.TheI/Oschedulerfoundinthe2.4LinuxkernelwasdesignedtomaximizeglobalI/Othroughput.IndoingsoatradeoffwasmadewithregardstofairnesswhichmeansthatIPPBXsystemsusinga2.4kernelaremorelikelytosufferfromschedulingdelays.Inordertodecidewhichtaskshouldrunnext,theschedulerhadtolookateachtaskandmakeacomputationtodetermineeachtask'srelativeimportance.Becausethetimerequiredtocompletethealgorithmvariedwiththenumberoftasks,applicationscouldsufferfromslowscheduling.

ThekernelI/Oschedulerembeddedinthe2.6kernelhasadvancedtheI/OcapabilitiesofLinuxsignificantly.TheschedulerinLinux2.6nolongerscansalltaskseverytime.Instead,whenataskbecomesreadytorunitissortedintopositioninaqueue.Whentheschedulerrunsitselectsthetaskatthemostfavourablepositionwithinthequeue.Thismeansthatschedulingisdoneinaconstantamountoftime,whichisidealforaudioapplicationslikeIPPBXsoftware.Whenataskisrunningitisgivenaperiodoftimeinwhichitmayusetheprocessorbeforeithastogivewaytoanotherthread.Whenitstimeperiodhasexpiredthetaskismovedtoadifferentqueueaccordingtoitspriority.ThisnewI/Oschedulerinkernel2.6isconsiderablyfasterthantheoldone,anditworksequallyaswellwhethertherearealargenumberoftasksinthequeueorjustafew.

Thereareactually4I/Oschedulersembeddedinthe2.6kernelthatcanbeselectedatboottime,eachofwhichoffersadifferentcombinationofoptimisations.ThealternativeschedulersaretheCompletelyFairQueuingelevator(cfq),Deadlineelevator(deadline),NOOPelevator(noop),andAnticipatoryelevator(as).TheI/Oschedulersarecalledelevatoralgorithmsbecausetheyaddressaproblemsimilartothatofkeepinganelevatormovingsmoothlyinalargebuilding.Thedefaultschedulerisusuallyasorcfqdependingonthedistribution.

InadditiontotheI/Oschedulerimprovements,thereareanumberofotherperformanceenhancingimprovementstothe2.6kernelincludingbetterdrivers/featuresetsforIDE/SCSIdrives,supportforkernelpreemption,andanimprovedthreadingmodel/library. TheLinux2.6Kernelalsoincludeanewprocessschedulerthatscalesbetterinmultiprocessor,multicoreandhyperthreadedCPUsystemsthanthe2.4kernelprocessscheduler.

4.2.2 DisableXWindowsandFramebuffer

XWindowsgeneratesalargenumberofinterrupts(especiallywhenusinganinputdevicesuchasamouse)thatcandelaytheprocessingoftelephonycardinterrupts.ItcanbeusefultorunXwhenconfiguringtheIPPBXsystem,butoncethesystemupandrunningitisadvisabletodisableXWindowsbychangingtherunlevel.

AlmostallLinuxdistributionuserunlevel2/3fortextmodeandrunlevel5forGUImode.Therunlevelmodesaredefinedinthe/etc/inittabconfigurationfile.IftheIPPBXsystemiscurrentlyusingXWindowsthen:

#cat/etc/inittab

shouldshowthefollowinglineintheconfiguration:

id:5:initdefault:

TodiableXWindowsbysettingthedefaultrunlevelto3(textmode)changethelineusingatexteditor(e.g.vi,nano,etc.)to:



id:3:initdefault:

NexttimetheIPPBXsystemisrebooteditwillbootintextonlymode.

TheLinuxframebuffer(fbdev)usedtodisplaygraphicsonaconsolewithoutrelyingonsystemspecificlibrariesorXWindowscanalsocauseinterruptprocessingissues.Theframebuffercanbedisabledbyincludingthe"vga=normal"optioninthegrubbootloader.

4.2.3 ChangeIDEHardDriveSettings

HarddiskcontrollerscancauseaudioissuesiftheyconsumetoomuchPCIbusresourcesastheycancausetheOpenSourcetelephonycardtosufferfrominterruptlatency/misses.TodetermineifyourIDEharddiskiscausingissuesyouuse:

#hdparmt/dev/[IDEDrive]

ThehdparmtcommandcausesasubstantialamountsofI/OtobegeneratedontheIPPBXsystem.Ifaudioissuesareexperiencewhilstusinghdparmtthenthissignifiesthatthereisaharddriveissue.

WhenusingIDEdrives,DigiumrecommendsusingDirectMemoryAccess(DMA)modewithanUltraDMA(UDMA)settingof2or3.UDMAmode2isATA33andUDMAmode3isATA44.TosettheharddrivetoUDMAmode2forexampleuse:

#hdparmd1Xudma2c3/dev/[IDEDevice]

Inthecommandabovetheoptiond1enablesDMAmode,Xudma2setstheIDEtransfermodetoUDMAmode2andc3enables32bitdatatransfers.ItshouldbenotedthatanychangestoharddrivesettingswillonlybeuseduntiltheIPPBXisrebooted.Therefore,toensuretheharddrivesettingsremainwhentheIPPBXisrebootedthehdparmcommandneedstobeincludedinoneoftheIPPBXstartupscripts.

4.2.4 AssignIRQstoSpecificProcessors

Dualcore/processorIPPBXsystemsrunningaSymmetricMultiProcessing(SMP)kernelallowIRQstobeboundtosingleormultipleCPUs.ItisadvantageoustobindtheX100PSEcardIRQtoaseparateprocessorusedforotherIRQs,particularlyIRQsallocatedtothinglikeIDEdrives.UsingaseparateCPUfortheX100PSEcardreducesinterruptlatencyandalsoimprovescachecoherencywhichreducescachemisses.

BeforebindingtheX100PSEcardIRQtoaspecificprocessorfirstofalltheirqbalancedaemonshouldbedisabledotherwiseitwilloverridethebinding.Thiscanbeachievedusingthefollowingcommands:

#servicestopirqbalance#chkconfigirqbalancelevel345off

TobindtheIRQstoaparticularprocessorfirstofallcheckwhichIRQhasbeenassignedtoeachdeviceusing:

#cat/proc/interrupts

CPU00:29421608IOAPICedgetimer1:39IOAPICedgei80428:3IOAPICedgertc9:0IOAPIClevelacpi

14: 287820IOAPICedgeide0



205:12333IOAPICleveleth0209:8001IOAPIClevelide1217:29406181IOAPIClevelwcfxo

MakeanoteoftheIRQsforeachperipheraldevice,anydiskdrivesandyourtelephonycard.Nextchangetheassignmentsusingthefollowingcommands:

#echo1>/proc/irq/217/smp_affinity#wcfxo#echo2>/proc/irq/14/smp_affinity#ide0#echo2>/proc/irq/205/smp_affinity#eth0#echo2>/proc/irq/209/smp_affinity#ide1

UsingthecommandsabovethetelephonycardIRQ(inthiscaseanX100PSE)hasbeenassignedtoprocessor1,whilstallotherrelevantIRQshavebeenassignedtoprocessor2.

OncetheIRQbindingconfigurationhasbeencompleted,eachoftheechocommandsusedshouldbeaddedtothe/etc/rc.d/rc.localfiletoensurethattheIRQbindingswillremainwhentheIPBPXserverreboots,i.e.

#cat/etc/rc.d/rc.local

Shouldinclude:

echo1>/proc/irq/217/smp_affinity#wcfxoecho2>/proc/irq/14/smp_affinity#ide0echo2>/proc/irq/205/smp_affinity#eth0echo2>/proc/irq/209/smp_affinity#ide1

Pleasenote:IfPCIBusdevicesareremovedoraddedtothesystemthentheIRQassignedmaychange.Thereforethestepsaboveshouldberepeatedafterremoving/addingPCIBusdevicestoensuretheIRQsremainassignedtothemostappropriateprocessor.

4.2.5 ChangeIRQPriorities

IftheIPPBXCPUgetstwointerruptsatthesametime,itwillanswertheminorderofprioritybasedontheIRQofthedevicerequestingtheinterrupt.Thereforeonewaytoreduceinterruptlatency/missesistouseanIRQwithahigherpriority.

IRQsareprioritizedandservicedinpriorityorderbytheCPUasdeterminedbythecontroller. WhenastandardXTProgrammableInterruptController(XTPIC)isbeingusedIRQs8through15haveahigherprioritythanIRQs3through7.TheIRQpriorityorderisshownbelowwithprioritydecreasingfromlefttoright(0hasthehighestpriority,7thelowest):

[0128910111213141534567]

ItmaybepossibletoassignacardanIRQwithahigherprioritybymovingittoadifferentslotorbytryingsomeoftheothersuggestionsforchangingIRQassignmentslistedinSection3.2.

IfanAdvancedProgrammableInterruptController(APIC)isbeingusedtheninterruptpriorityisn'trelatedwiththepin,butthevectorofthepin.Howthevectorofapinisallocatedisquiterandom.UsuallythedevicedriverthatcommunicateswiththePCIcontrollerfirstwillgetalowerpriorityvector.Therefore,whichvectorgetsallocatedtoadevicedependsonhowmanydevicedrivershavealreadycontactedthePCIcontroller.Thereisnomethodavailableforreserving/settingvectorsforadevice/IRQandnowayofcheckingwhatvectorhasbeenassignedtowhatIRQ.ThereforeifIAPICisbeinguseditisnotpossibletotryandassignacardwithahigherpriority.



4.2.6 ChangeIRQLatencyTimerSettings

EvenifyoumanagetoassignanIRQwithahigherprioritytoyourcard,alowerpriorityinterruptcanstillblockhigherpriorityinterruptsifittakesovertheprocessorforseveralmillisecondsanddisablesallotherinterruptsduringthattime.Anotherwaytotryandreduceinterruptlatency/missesistochangethedefaultIRQlatencytimers.Interruptlatencyisthetimebetweenthegenerationofaninterruptbyadeviceandtheservicingofthedevicewhichgeneratedtheinterrupt.Thereisusuallyatradeoffbetweeninterruptlatency,throughput,andprocessorutilization.

PCIbuslatencytimerscanrangefrom0to248,thelowerthefigurethequickerthedevicewillgiveupthebus.Ifadevicehasasettingof0,thenitwillimmediatelygiveupthebusifanotherdeviceneedstotransmit.Ifadevicehasasettingof248,itwillcontinuetousethebusforalongerperiodoftimebeforestoppingwhilsttheotherdevicewaitsforitsturn.ItistheroleofthedevicedrivertosetthecorrectPCIbuslatencytimervalueforthePCIdeviceandmostofthetimethedefaultsettingsworkwell.

UsinglowPCIbuslatencytimersettingsresultsindevicesquicklygivingupthebusifanotherdeviceneedstotransmitdata.Theadvantageofthisapproachisthatitresultsinamuchlowerdatatransmitlatency,sincenodeviceisgoingtoholdontothebusforanextendedperiodoftimecausingotherdevicestowait.However,thisalsoreducestheeffectivePCIbusbecauselargedataburstsbecomemuchlessfrequentandrapidchangesinbuscontrolincreasesoverhead.ConfiguringthemajorityofdeviceswithhighPCIbuslatencytimersettingsincreasesinterruptlatency,butalsoincreasethroughput.Aseachdevicegetstoburstlargeamountsofdataacrossthebuswithoutinterruption,thePCIbusisusedmoreefficientlyandthePCIdevicescantransmitmoredata.

Ingeneral,thebestapproachtoreducinginterruptlatencyistoassignahigherPCIbuslatencytimertotheOpenSourcetelephonycardandassignalowerPCIbustimertotheotherPCIbusdevices.ThishelpstoensurethattheotherPCIbusdevicesgiveupthePCIbuswhentheOpenSourcecardneedsit.

However,itshouldbenotedthatifanIPPBXisbeingusedtoprovidemultipleservicesthatrequirelargeamountofdatatobesent/processed,e.g.file/webserver,firewall,etc.thenloweringthePCIbustimerforthingsliketheIDEdrivemayactuallydecreaseperformance.Insuchcases,CPUutilisationmayincreasesignificantlyduetheprocessornothavingenoughtimetosendthevolumeofdatarequiredandduetothefrequencyofPCIbuscontrolchanges.Therefore,insomecasesitmaybemorebeneficialtoactuallyincreasethePCIlatencyofsomeoftheotherdevicesinordertoallowthemtoburstrelativelylargeamountsofdataacrossthebusinonego.EachsystemisdifferentandthereforeitisacaseoftrialanderrorinfindingtheoptimumPCIbuslatencysettings.

BeforechangingthePCIBuslatencytimersettings firstofallweneedtofindoutthespecifiedbus,slotandfunctioninformationforeachPCIbusdevicewewanttochangethelatencyfor.Thisinformationisprovidedinthe[[]:][][.[]] formatnexttoeachPCIdevicewhenissuingthelcpcivcommand.Forexample:

#lspciv

00:0f.0IDEinterface:VIATechnologies,Inc.Unknowndevice5337(rev80)(progif8f[MasterSecPSecOPriPPriO])

Subsystem:FoxconnInternational,Inc.Unknowndevice0c87Flags:busmaster,mediumdevsel,latency32,IRQ11Capabilities:[c0]PowerManagementversion2

04:04.0Ethernetcontroller:RealtekSemiconductorCo.,Ltd.RTL8139/8139C/8139C+(rev10)

Subsystem:FoxconnInternational,Inc.Unknowndevice0c87



Flags:busmaster,mediumdevsel,latency32,IRQ209I/Oportsat9c00[size=256]Memoryatdfaff000(32bit,nonprefetchable)[size=256]Capabilities:[50]PowerManagementversion2

04:06.0Communicationcontroller:MotorolaWildcardX100PSubsystem:EfarMicrosystemsUnknowndevice0001Flags:busmaster,mediumdevsel,latency32,IRQ217I/Oportsat9800[size=256]Memoryatdfafe000(32bit,nonprefetchable)[size=4K]Capabilities:[40]PowerManagementversion2

Aftermakinganoteoftherelevantbus,slotandfunctiondetailsforeachdevicethePCIlatencytimersvaluescanbechangedusingthefollowingcommands:

#setpcivs04:06.0LATENCY_TIMER=f8#wcfxo#setpcivs00:0f.0LATENCY_TIMER=8#ide0#setpcivs04:04.0LATENCY_TIMER=8#eth0#setpcivs00:0f.0LATENCY_TIMER=8#ide0

UsingthecommandsabovethePCIlatencytimerfortheOpenSourcetelephonycard(inthiscaseanX100PSE)hasbeenincreasedtothemaximumof248(F8inhex),whilstthePCIlatencytimersfortheotherPCIdeviceshavebeenreducedto8.

AfterthePCIlatencytimershavebeenconfiguredusingthecommandsabove,eachofthesetpcicommandsusedshouldbeaddedtothe/etc/rc.d/rc.localfiletoensurethatthePCIlatencytimerswillremainwhentheIPBPXserverreboots,i.e.

#cat/etc/rc.d/rc.local

Shouldinclude:

setpcivs04:06.0LATENCY_TIMER=f8#wcfxosetpcivs00:0f.0LATENCY_TIMER=8#ide0setpcivs04:04.0LATENCY_TIMER=8#eth0setpcivs00:0f.0LATENCY_TIMER=8#ide0

Pleasenote:IfPCIBusdevicesareremovedoraddedtothesystemthentherelevantbus,slotandfunctiondetailsmaychange.Thereforethestepsaboveshouldberepeatedafterremoving/addingPCIBusdevicestoensurethePCIlatencytimervaluesremainoptimal.



5 Echo


Echoisthetermusedtodescribetheexperienceofhearingyourownvoicebackduringatelephonecall.TherearetwomainsourcesofechoinIPPBXsystems:

AcousticechoGenerallycausedbyfeedbackfromthetelephonehandset Lineecho Dependantontheimpedancecharacteristicsofthelinetotheexchange

Thetwomainfactorsthatdeterminehowseriousechoisarethetimeperiodafterwhichyouheartheechoandtheloudnessoftheecho.Iftheechoisfairlyquiteandthereareonlyafewmillisecondsofdelaythentheechomaybequitebearable.However,ifthedelayisafewhundredmillisecondsandtheechoisquiteloudthenitcanbeextremelyannoyingandevenrenderthevoiceserviceunusable.

5.1.1 AcousticEcho

Acousticechoisusuallycausedbyvoicetravellingoutoftheearpieceorspeakerbackintothemouthpieceormicrophone,althoughitcanalsobecausedbysoundbouncingoffthewallsofaroom.Acousticechoisonlyusuallyanissuewhenusinglowqualityorincompatibleheadsets,orwhenusingaspeakerphone.However,itcanalsooccurwhenusingatelephonehandsetifthemicrophoneissensitiveandthevolumeofthehandsetspeakerisquiteloud.WhensufferingfromacousticechoboththelocalandremotepartieshearechowhenspeakingandechoispresentwhencallinganotherextensionconnectedtothesameIPPBX.Acousticechovariesinstrengthanddelaydependingonthechangingacousticenvironmentoftheechosource,e.g.movingamicrophonefurtherawayfromaheadset.

5.1.2 LineEcho

LineechoiscommoninPSTNnetworksandiscausedbyimpedancemismatches.Lineechoisapropertyofthelineconnectionandremainsmostlyconstantthroughoutthecall. WhenmakingacalloverthePSTN,thesignalpathbetweentwotelephonesrequiresamplificationusingafourwirecircuit.Fourwirecircuitsarenotextendedtocustomerpremisesduetocost,insteadthefourwirecircuitsarecoupledtotwowirecircuitsusingadevicecalledahybrid.Thehybridinthetelephoneprovidersexchangecouplestheanaloguesignalfromthefourwirecircuit(whereincomingandoutgoingsignalsareseparated)tothetwowirecircuitwheretheincomingandoutgoingsignalsarecombined.

Assignalspassfromthefourwiretothetwowireportionofthenetwork,theenergyinthefourwiresectionisreflectedback,creatinganechoofthesignal.Theseverityoftheechodependsonhowwelltheimpedanceismatchedbetweenbothsidesofthehybrid.Theimpedanceofthetwowirecircuitcanvarysignificantlydependingonfactorsincludingthelinesetupintheexchangeequipment,thedistancebetweentheexchangeandtheIPPBX,theelectricalcharacteristicsofthewire,etc.Theactualamountofsignalthatisreflectedbackdependsonhowwellthebalancecircuitofthehybridmatchesthetwowireline.

LineechoisntanissuewhenusingastandardanaloguePOTStelephoneasthereflectedvoiceisheardbackatthesametimeasyouarespeaking.Ifthedelayisunder5msitmergeswiththesidetone,whichisthesoundofyourownvoiceinyourearpieceandbecomesunnoticeable.However,whenusingatelephoneconnectedtoanIPPBXthevoiceisdelayedslightlyduetothespeechencodinganddigitalprocessing,whichresultsinecho.Thehybriddeviceintheprovidersexchangeissupposedtosubtractthecorrectproportionofthesignaltransmittedinordertoeliminatetheechofromthelocalloopbackportionofthecircuit.Unfortunatelythoughpoorlydesignedhybriddevicesareoftenusedanditsverycommonforimpedancesettingstobeimproperlybalanced.



Itshouldbenotedthatitispossibleforsomecalls madeusingaPSTNlinetosufferfromechoproblemswhilstothercallsmadeoverthesamelineremainechofree.Forexample,longdistancecallsover600kmareroutinelyechocancelledateachendandmobilephonecallstothePSTNarealsoechocancelledsothesetypesofcallwillnotsufferfromechoissues.

Inadditiontoechocausedbyhybridbalancingissuesintheexchange,poorqualityinbuildingcablingandsplitterscanalsogenerateechoduetobouncebackcausedbyimpedancevariations.

5.2 Solution

5.2.1 CheckforAcousticEcho

Whensolvingechoissuesthefirststepistomakesurethatthesourceoftheechoisnotacousticechobeingcausedbyatelephonehandset/softphone.Methodstodeterminewhetherornottheissueisduetoacousticechoare:

Doestheremotepartyhearechoorjustthelocalparty?Ifitsbothpartiestheechomustbeacousticecho.

TrymakinganinternalcallbetweenextensionsconnectedtothesameIPPBXoracalloveraSIPtrunk,iftheechoisstillpresentit mustbeacousticecho.

Holdyourhandoverthemouthpiece/microphoneduringacalltoseeiftheechoisstillpresent.

Ifitisacousticechothereareanumberofrelativelysimplesolutionsavailable:

Tryturningdownthevolumeonthehandset/speakerphone,mostacousticechoproblemscanbegreatlyreducedbysimplyturningthevolumedown.

Trymovingthespeakerphonetoaroomthatislesslikelytocreateecho,e.g.acarpetedroomwithsoftfurniturethatcanabsorbthesoundratherthanreflectitback.

Tryusingadifferenthandset/headset/speakerphone.

5.2.2 ChecktheZaptelModuleOperatingMode

IftheechocanonlybeheardwhenmakingcallsusingaPSTNlinethentheechomustbelineecho.Theprimaryobjectindealingwithlineechoistotryandpreventtheechofromoccurringinthefirstplace.AllOpenSourcetelephonycardssoldbyNovavoxhavetuneableparametersthataffecttheoperatingcharacteristicsandhaveanimpactonvoicequalityandecho.Someoftheparametersarecountrydependant,andthereforethezapteldrivermoduleforthecardneedstoknowwhichcountryparametertouse.

Tosetthecorrectoperatingmodetheappropriateoptionneedstobeaddedtothe/etc/modprobe.conffile.

Note:DebianbasedLinuxdistributionslikeUbuntudonothavea/etc/modprobe.conffile.Insteadmodulescanbeloaded/unloadedbycreatingaconfigurationfilewiththerelevantoptionsandstoringitinthe/etc/modprobe.d/directory.Forexample,youcouldcreateafilecalled modprobe.confin/etc/modprobe.d/andaddthelinesdescribedabove.Aftercreatingthefilerunupdatemodulestomergethechangeswiththesystemmodulesconfiguration.

TheoptionsareOpenSourcetelephonycardspecific,twoexamplesareprovidedbelow:

X100PSEcards

ThedefaultoperatingmodefortheZaptelwcfxodriverisFCC/USlinestandards.TochangetheoperatingmodetoCTR21tosupportEuropeanlinestandardsaddthefollowinglinestomodprobe.conf:



optionswcfxoopermode=1installwcfxo/sbin/modprobeignoreinstallwcfxo&&/sbin/ztcfg

ThenshutdownandrestarttheIPPBX:

#shutdownrnow

Tocheckthatthecorrectmodeisinoperationusethefollowing:

#dmesg|more

Theoutputshouldinclude:

...wcfxo:DAAmodeis'CTR21'FoundaWildcardFXO:WildcardX100P...

ThisconfirmsthatthecardisrunninginEuropeanCTR21mode.

Pleasenote:TheZaptelwcfxodriveronlysupportsCTR21modewith600ACtermination,whichmayormaynotbethecorrectsettingdependingonthecountryandthephonesysteminuse.Forexample,intheUKBTPSTNlinesusecompleximpedance,whereasPSTNlinesfromsomecablecompaniesmayuse600impedance.Also,theSiliconlabsSi3014/Si3034DAAchipusedontheX100PSpecialEdition(SE)soldbyNovavoxsupportsgloballinestandards.However,theSi3012/Si3035DAAchipusedintheoriginalDigiumX100PcardandlowcostX100PclonecardsonlysupportsFCC/JATElinestandards.Therefore,unlessyouhaveanauthenticX100PSEcarditisunlikelythatyourX100PcardwillsupportEuropeanCTR21mode.

Tosupportgloballinestandardswehaveputtogetherasetupguidethatusesapatchtoprovideadditionaloperationalmodestosupportlinestandardforallcountries.IfyourcountryisnotsupportedbythedefaultFCCmodeorCTR21600impedancemodethenusetheinstructionsinthefollowingguidetoconfiguretheappropriatesettingsforyourcountry:

NovavoxX100PSEGlobalLineStandardsSetupGuide

OpenVoxA400Pcards

ThedefaultoperatingmodefortheZaptelwctdmdriverisFCCUSlinestandards.Tochangetheoperatingmodetosupportthelinestandardsforadifferentcountryaddthefollowinglinestomodprobe.conf:

...optionswctdmopermode=installwctdm/sbin/modprobeignoreinstallwctdm&&/sbin/ztcfg...

Forexample,thecountrycodefortheUKisUK.AlistofcountrycodesforothercountriesisprovidedinAppendixB.Pleasebeawarethatnotallcountrycodesaresupported.

AfterconfiguringthecorrectoperatingmodeforyourcountryshutdownandrestarttheIPPBX:

#shutdownrnow

Tocheckthatthecorrectmodeisinoperationusethefollowing:



#dmesg|more

Theoutput(usingtheUKoperatingmodeasanexample)shouldinclude:

Module0:InstalledAUTOFXO(UKmode)Module1:InstalledAUTOFXO(UKmode)Module2:InstalledAUTOFXS/DPOModule3:InstalledAUTOFXS/DPO

ThisoutputisforanOpenVoxA400P22with2FXSandFXOmodules,theoutputwillvarydependingonthemodulesinstalled.

5.2.3 BalancingtheHybrid

SomeOpenSourcetelephonycardssuchastheOpenVoxanaloguecardrangesoldbyNovavoxhaveaprogrammabledigitalhybridfornearendechoreduction.FxotuneisatoolusedtoautoconfigurethePSTNlineimpedancesettingsforcardsthathaveaprogrammabledigitalhybrid.Beforeusingthefxotunetool,firstofallensurethattheFXOportsareconnectedtothePSTNandthenstopAsterisk(otherwisefxotuneconsidersthelinesasbusy):

#amportalstop/CLI>stopnow

Nextstartthefxotunetool:

#fxotunei5

Thenumber5isadialleddigitusedtobreakdialtoneontheline,anynumberthatwillbreakdialtoneonthelinemaybeused.TheioptioninstructsfxotunetotestthePSTNlineimpedanceforeachconnectedPSTNline(maytakeupto10minsperline)andsetthecorrespondingparametersinthefxotune.conffile(normallylocatedin/etc/).Oncecomplete,applythecalibrationsettingsdefinedinthefxotune.conffileusing:

#fxotunes

BeforefinallyrestartingAsterisk:

#amportalstart/#asterisk

EverytimeanewPSTNtrunklineisaddedorchangedfxotunei5shouldberun.

ThelatestZapteldriverversionsincludethecommandfxotunesintheZaptelinitscript(usuallylocatedin/etc/init.d/)toautomaticallyloadthefxotunecalibrationsettingswhenthesystemisreloaded.IfyouareusinganolderTrixboxversionlike2.2thenthefxotunescommandis includedin/etc/rc.d/rc.localscript.

TocheckwhetherornotthefxotuneicommandisalreadyincludedinoneofyourIPPBXscriptsopenuptherelevantscriptsusingatexteditorlikenanoandsearchthetextforfxotune.Ifthecommandisnotincludedthenadd/usr/sbin/fxotunestothe/etc/rc.d/rc.localscripttoensurethatthefxotunecalibrationsettingsareautomaticallyreloadedfollowingareboot.

5.2.4 Adjustingthereceive/transmitgain

OneofthefactorsthatcanhaveanimpactonechoisthesettingofcorrectRX/TXaudiogainvaluesforyourtelephonelineinthe/etc/asterisk/zapata.conffile.UnfortunatelythereisnosuchthingasastandardRX/TXgainsettingthatwillworkforallinstallationsaseveryinstallationisdifferentduetodifferencesintelephonelinequality,impendence,linelength,



etc.However,AsteriskprovidesausefultoolcalledztmonitortohelpsettheappropriateRX/TXgainvalues.Usingthecommand:

#ztmonitorv

Willprovideyouwiththefollowingoutput:

VisualAudioLevels.Usezapata.conffiletoadjustthegainsifneeded.

(#=AudioLevel*=MaxAudioHit)stopnow#amportalstart/#asterisk

TheRX/TXgainswillvarydependingonthelocationofthecalled/callingparty.Therefore,itisadvisablewhenusingztmonitortocalldifferentnumbersindifferentlocationstoachievetheoptimalsettings.

5.2.5 InbuildingCabling/Splitters

Amongstotherthings,poorqualityinbuildingcabling,longcablespans,splitterscancreateechoduetobouncebackcausedbyimpedancevariations.Ifyouthinkthequalityoftheinbuildingcabling/splitterscouldbeacauseofecho,thentryconnectingtheportontheIPPBXPSTNlinecarddirectlytotheexchangeNTEboxusingagoodqualitymodemcable.Ifthatfixestheissuethenfollowthecablingrouteandcarryoutsectionteststotryandlocatethesourceoftheecho.

5.2.6 IPPBXVoiceSwitchingDelay

Asstatedinsection4,themostimportantfunctionofanIPPBXsystemistoswitch/movedigitalsoundsamplesfromoneport/protocoltotheotheratveryconstantrate.IfthesoundsamplesaredelayedastheytraversetheIPPBXthenthiscancauseecho.ThedelayintroducedbyanIPPBXmaybeduetospeechencoding,digitalprocessing,orboth.



IfitissuspectedthattheIPPBXitselfcouldbethecauseoftheechothefirststepshouldbetocheckforandresolveanyIRQissuesusingthemethodsdescribedinSection4.

IftheredoesnotappeartobeanIRQissue,thenthegeneralperformanceoftheIPPBXshouldbeassessed.SysteminformationprovidedbyanIPPBXGUI(e.g.TheSystemStatusscreenintheTrixboxGUI)canprovidehelpfulinformationonsystemperformance,i.e.thingslikememoryusage,networkusageandfilesystemcapacity.Commandlinetoolsthatareusefulinclude:

#vmstatProvidesinformationonCPU/memoryusageaswellsystemI/Oinformation#uptime CPUloadinformationbasedon5,10,15minuteaverages#psaux Staticsnapshotoverviewofsystemprocesses#top Dynamicoverviewofsystemprocessesupdatedevery10seconds

SolvingIPPBXserverperformanceissuesisoutsidethescopeofthisdocument.However,thecommandslistedaboveshouldactasagoodstartingpointtohelpdetermineifthereisaperformanceissueandwhatthecausemaybetoallowasolutiontobefound,e.g. installextramemoryorremoveunnecessaryapplications/processes.

5.2.7 EchoCancellation

Background

Thesuggestionsaboveareallintendedtohelpstoptheechobeingcreatedinthefirstplace.Ifthesedonotworkthenthesolutionistouseechocancellationtoremoveechofromthevoicecommunication.Echocancellationfirstofallrequiresrecognizingtheoriginallytransmittedsignalthatafteradelayreappearsinthetransmittedorreceivedsignal.Torecognisetheechoreturnlevel(ERL)needstobelowerthantheoutputsignallevelbyacertainamountinorderforittointerpretthesignalasecho.Oncetheechocancellerrecognisestheechoitcanberemovedbysubtractingitfromthetransmittedorreceivedsignal.

Echocancellationcanbeimplementedinhardwareusingadedicateddigitalsignalprocessor(DSP),orinsoftware.Itisoftenassumedthathardwarebasedechocancellationissuperiortosoftwarebasedechocancellation.However,ahardwarebasedechocancellerisjustanechocancellationalgorithmimplementedinfirmwareonaDSPchip.ThereisnoinherentreasonwhythesamealgorithmcouldntworkequallyaswellinsoftwareonaCPU.Sayingthat,softwarebasedechocancellationdoeshaveanimpactonCPUusageanditsuseisnotfeasibleforlargenumbersofchannels,e.g.multipleE1/T1s.

Oneofthefactorsthatdetermineshowmuchprocessingresourcesasoftwarebasedechocancellerrequiresisthetailcircuitdelay.ThetailcircuitencompasseseverythingfromtheOpenSourcetelephonycardPSTNportallthewaydowntotheterminatingphone.Tailcircuitdelayisthetimeperiodbetweenthepointatwhichtheoriginalaudiosignalexiststheechocancellerandthetimeatwhichitreturnsasecho.Theechocancellerneedstokeeparecordoftheaudioithassentforatimeperiodequaltothetailcircuitdelaytodetermineifthesameaudiohascomeback.Tokeeparecordoftheaudioittakesdigitalsoundsamplesatsetintervalscalledtaps.

TheZaptel/Asteriskechocancellerstakedigitalsamplesatarateof8,000persecond,whichmeanstheintervalbetweeneachtapis0.125ms.ThedefaultnumberoftapsinAsteriskis128,whichwillhandleechopathsofupto16msandis usuallyadequateformostechoissues.Thenumberoftapsisalwaysconfiguredasapoweroftwo,i.e.32,64,128,or256.ThelowestnumberoftapsaspossibleshouldbeusedwhilestilladequatelycancellingtheechoasitreducesthecomputingloadandmemoryrequirementontheIPPBX.Also,thetrainingtimeisshorterandthecancellerwilladaptfaster.

Zapata.confEchoConfiguration



AnexampleZapata.confconfiguration(usuallylocatedin/etc/asterisk/) forenablingechocancellationisprovidedbelow:

echocancel=yesechocancelwhenbridged=noechotraining=400

echocancel

Thisparameterdisables[no]orenables[yes]echocancellation.Itisrecommendedtoleaveitenabledevenoftheredoesntappeartobeanechoissueunlessthereisareasonnotto,e.g.lackofCPUresource.The[yes]settingsetsthenumberoftapsto128,butanintegercanbeusedinsteadtochangethenumberoftapsto16,32,64,128,or256.

echocancelwhenbridged

Thisparametersenables[yes]ordisables[no]echocancellationwhenTDMcallsarebridged.GenerallyitsnotnecessaryoradvisabletoenableechocancellationsforbridgedTDMcallsbutitcanbeenabledifrequired.

echotraining

TheechotrainingoptioninAsteriskisamechanismforimprovingtheconvergencetimeoftheechocanceller.Transmittedvoiceisdisabledforashorttimeperiodduringringingandaspikeofsoundistransmittedtomeasurethedifferenceinthereceivedechoandtransmittedsignaldirectlyinsteadoflearningititerativelyovermanysamples.Theechotrainingoptioneliminatesmostoftheechoatthebeginningofthecallinthemajorityofcases.Validsettingsforechotrainingare102000millsecondswhichspecifiesthedelaybeforetraining.

Pleasenote:echotrainingisnotsupportedbytheOpenSourceLineEchoCanceller(OSLEC)andmustbecommentedoutotherwiseitwillcausethechanneltobesilent.OSLECisinstalledbydefaultinTrixboxversions2.4andupwardsandoffersbetterechocancellationperformancethanthezaptelechocancellers.

RemovingEcho

Theechocancelandechotrainingoptionsmayneedtobefinetunedinordertogetridofechocompletely.DifferentparametersshouldbeusedonaniterativetrialanderrorbasisuntiltheoptimumechocancelandechotrainingsettingsaredeterminedforanIPPBXsystem.

Itisadvisabletostartwithanechocancelsettingof32andaechotrainingsettingof100.Incrementtheechotraininginstepsof100butdonotexceedanechotrainingsettingof1200.Asteriskmustberestartedeachtimeoneoftheparametersismodifiedinorderforthechangestotakeeffect.Ifechoisstillpresentafterreachinganechotrainingsettingof1200,incrementtheechocanceloptiontothenextsetting(64)andrepeattheprocessuntiltheechoiscompletelygone.

Tospeeduptheprocedureyoucanincreasethesettingsusinglargerintervals(e.g.increasetheechotrainingdelayby400eachtime)andcanevenstartatthehighestsettingsandworkbackiftheechoisextremelybad(e.g.256taps,1200millsiceondstraining).

ChangingtheEchoCanceller

Ifthereisstillechopresentafterfollowingtheproceduredescribedabovethenitispossibletotryusingadifferentechocanceller.OneoptionistotrytheOSLECechocanceller,instructionsoninstallingtheOSLECechocancellercanbefoundhere:

http://www.rowetel.com/ucasterisk/oslec.html#install



AnotheroptionistotryadifferentZaptelechocanceller.InolderZaptelversionsthedefaultechocancellerisECHO_CAN_KB1.AnewerechocancellerisECHO_CAN_MG2,whichisthedefaultfornewerZaptelversions.ItalsopossibletousetheAGGRESSIVE_SUPPRESSORinconjunctionwithECHO_CAN_MG2foraggressiveresidualechosuppression.

Tochangethedefaultechocancelleryouneedtoopenupthezconfig.h file(locatedin/user/src/zaptelor/user/src/zaptel/kernel)usingatexteditorlikenanoandcommentin/outtherequiredechocanceller.Forexample,ifyourdefaultechocancellerwasECHO_CAN_KB1andyouwantedtochangetoECHO_CAN_MG2withAGGRESSIVE_SUPPRESSORyouwouldneedtoedityourzconfig.hfilesoitshows:

/**Pickyourechocanceller:MARK2,MARK3,STEVE,orSTEVE2:)**/

/*#defineECHO_CAN_STEVE*//*#defineECHO_CAN_STEVE2*//*#defineECHO_CAN_KB1*//*Thisisthenewlatestandgreatest*/#defineECHO_CAN_MG2

.*Uncommentforaggressiveresidualechosuppressionunder*MARK2,KB1,andMG2echocanceler*/

#defineAGGRESSIVE_SUPPRESSOR

AfterchangingthefilesaveitandthenrecompileAsterisk.InstructionsondownloadingandcompilingtheZaptelsourcecodeitcanbefoundinAppendixD.

OctWareSoftEcho

Analternativetospendingtimetweakingzapata.confsettingschangingrx/txgainsistosimplyinstallOctWareSoftEcho.TheSoftEchoalgorithmisautotuningmeaningthatnoadjustmentsarenecessarymakingintegrationquickandsimple.SoftEchoprovidescarriergradevoicequalityforAsteriskIPPBXvoicechannels,keyfeaturesinclude:

Excellentdoubletalkhandling Fastconvergence Highqualitybackgroundnoisehandling Longechotailupto128ms Performanceandvoicequalitystatistics Autotuningtransparentalgorithm Dialtoneanddigittransparency G.1682004compliant

LeveragingOctasic'ssoundprocessingexpertisebasedonyearsofexperienceintrunksideaswellaslocalsidenetworkechocancellation,OctWarehavedevelopedasoftwarebasedechocancellingalgorithmcalledSoftEcho.Withsupportforupto16voicechannels,SoftEchoisacosteffectivewayforAsteriskIPPBXintegratorstooffercarriergradevoicequality.SoftEchoeffectivelyeliminatescustomers'supportcallsaboutunsatisfactoryvoicequality.SoftEchocanbeusedwithanyOpenSourcetelephonycardsincludinganaloguecardsliketheX100PSEanddigitalcardsliketheOpenVoxB100P.

OctWareSoftEcholicencesareavailabledirectlyfromNovavox:

http://www.novavox.co.uk/products/software/softecho.html



6 FarendDisconnect


Farenddisconnectisthetermusedtodescribethesituationwhenthefarendhangsupduringatelephonecall,i.e.theremoteendfromtheperspectiveoftheIPPBX.Ifalocaluserisonthephonewhenthefarenddisconnectstheuserwillknowthecallhasendedandwillhangupthephoneatlocalend.However,eventhoughthelocaluserhangsuptheIPPBXmaynotreleasethePSTNlineifitthinksthatthefarendisstillconnected.Also,ifsomeoneisleavingavoicemailmessagethentheIPPBXneedstoknowwhenthefarendhashungupotherwiseitwillrecordsilenceordial/busytone.

ThemethodbywhichtheIPPBXlearnsthatthefarendhasdisconnectedisknownasdisconnectsupervisionsignalling.Themostreliableformofdisconnectsupervisioniswherethelocalexchangedropsbattery/voltagemomentarilyonthephonelinetoindicatetothephone/PBXthattheotherendofthepartyhasdisconnectedthecall,i.e.toprovidehangupnotification.This voltagedropisknownasCPC(CallingPartyControl)orDisconnectClearTime(DCT)intheUK.Thistypeofdisconnecthasvariousnamesindifferentcountriesincludingforwarddisconnect,batteryremoval,openloopdisconnectandclearforwardanswerreversal.

Anothertypeofdisconnectsupervisionsignalusedinsomecountriesisreversepolarity,alsocalledreversebattery.WhenreversepolaritydisconnectsupervisionisbeingusedthePSTNproviderreversesthepolarityofthebatterycurrentforbothanswersupervisionanddisconnectsupervision.

Theleastreliablemethodofdisconnectsupervisionistheuseofdisconnect/busytone.WhenthefarenddisconnectstheIPPBXreceivesadisconnect/busytonetoindicatethatthecallisdisconnected.

FarenddisconnectissuesarisewhenthefarenddisconnectsbuttheIPPBXdoesnotreceiveormisinterpretsthedisconnectionsupervisionsignal.

6.2 Solution

Thefirstthingtocheckwhenexperiencingfarenddisconnectissuesthatthecorrectsignallingtypeisconfiguredinthezaptel.conf(e.g.fxsks=1)andzapata.conf(e.g.signalling=fxs_ks)configurationfiles.KewlstartisthepreferredsignallingprotocolforanaloguecircuitsinAsteriskandisthesignallingprotocolthatshouldbeusedintheUKandthemajorityofEuropeancountries.AsummaryofthedifferentsignallingmethodsisprovidedinAppendixA.

IfyourPSTNproviderusesvoltage/batterydropfordisconnectsupervisionbutfarenddisconnectisnotworkingthentheCPC/DCTprovidedbythePSTNprovidermaybesettoolow.ForexampleintheUKtheidealDCTis800ms,however,itmaybesetaslowas100msandmaynotbedetectedbyyourIPPBX.TosolvethisissuecontactyourPSTNproviderandaskthemtoincreasetheCPC/DCTforyou.

IfyouPSTNproviderprovidesreversepolarity/batterydisconnectsupervisionthenthefollowingtwolinesshouldbeincludedinthezapata.conffile:

hanguponpolarityswitch=yesansweruponpolarityswitch=yes.



Forlinesthatrelyondisconnect/busytonedisconnectsupervisionthefollowinglinesshouldbeincludedinthezapat.conffile:

busydetect=yesbusycount=6

WithbusydetectenabledAsteriskwilllistenforbusysignalsontheline,ifyourPSTNprovidersendsyouabusytonefollowingfarendhangupAsteriskshoulddetectit.Itshouldbenotedthatthisoptionislessreliablethanotherhangupdetectionmethodsandassuchshouldonlybeusedifitstheonlyoptionavailable.Busycountisthenumberofbusytonestodetectbeforerecognisingthatthefarendhasdisconnected.Thelowerthevaluethequickerthecallwillhangup,butthereisatradeofftconsiderasthis increasesthepossibilityoffalsehangups.

Youcanalsotryenablingcallprogress,andsetyourprogzonetoyourcountrycode(seeappendixB).Thisoptionissimilartothebusydetectoption,butwillalsolistenforaringingtone,congestiontoneandwilltrytodetectifthelinegotanswered.However,callprogressisexperimental,soifyouexperiencefrequentdisconnects,youshoulddisableit.



7 KernelPaniconReboot


SometimesafterinstallinganewOpenSourcetelephonycardyoumaygetaKernelpanicerrorsimilartotheoneshownbelowwhenyoureboottheIPPBX:

Code:BadEIPvalueFatalexception:panicin5secondsKernelPanicnotsyncing:Fatalexception

TheissueeffectssomeIPPBXbuildsbutnotothersandisduetotheZaptelmodulesbeingunloadedbeforeAsteriskhasbeenstoppedwhenrebooting.

7.2 SolutionTosolvetheissueweneedtostopthezaptelmodulesfrombeingunloadedbeforeAsteriskisstoppedwhenrebooting.Thiscanbeachievedbycommentingoutthesectionthatunloadsthedriversinthezaptelstopscriptlocatedinthe/etc/rc6.ddirectory,i.e.thedirectorythatcontainsthescriptsthatareexecutedwhenthesystemisrebooted.

ThenameoftherelevantscriptisKxxzaptel,wherexxisanumberbetween0099(thenumbercorrespondstotheorderinwhichthescriptisexecuted).InourTrixbox2.6.07testsystemtherelevantscriptis/etc/rc6.d/K92zaptelandtherelevantlinesthatneedtocommentedout(byplacinga#atthestartofeachline)areshownbelow(lines228233andline238)asshownbelow:

stop)#Unloaddrivers#shutdown_dynamic#FIXME:needstestfromsomeonewithdynamic

spans#echon"Unloadingzaptelhardwaredrivers:"#unload_modulezaptel#RETVAL=$?#echo"."

#[$RETVALeq0]&&rmf$LOCKFILE

unload)#Wedon'thavezaptelhelper,solet'snotreplicatetoomuch

code:#allowotherstousetheunloadcommand.#unload_modulezaptel

InolderZaptelversionstherelevantlinesare115123asshownbelow:

#Unloaddrivers#echo"Unloadingzaptelhardwaredrivers:"#forxin$RMODULESdo#action"Unloading${x}:"rmmod${x}#done#action"Removingzaptelmodule:"rmmodzaptel#RETVAL=$?

#[$RETVALeq0]&&rmf/var/lock/subsys/zaptel

Therelevantlinesinyourzaptelstopscriptmaybeslightlydifferentthesectiontolookoutforistheonethatsaysincludes"Unloaddrivers".



IfamendingthezaptelstopscriptdoesntfixtheissuethenyouwillneedtoensurethatAsteriskisshutdownbeforerebooting,i.e.

#amportalstop/CLI>stopnow#shutdownrnow

ItisadvisabletoaddthecommandtostopAsterisktooneoftherebootsscriptstoensurethatAsteriskisalwaysstoppedbeforetheZaptelmodulesareunloadedwhentheIPPBXserverisrebooted.



8 QuickReference

UsefulCommands

Command Description#amportalstart StartAsterisk#amportalstop StopAsterisk#asteriskr ConnecttotheAstersikCLI

#cat/proc/interrupts ListsPCIbusdrivers/devicesrecognisedbytheLinuxKernelalongwiththeallocatedIRQ

#chkconfig Commandforadding/removinggstartupscriptsandmanagingwhichrunleveltheyoperateat

#dmesg|more DiagnosticmessagecommandusedtolookattheKernelsbootprocessmessagebuffer

#fxotune ToolusedtoautoconfigurethePSTNlineimpedancesettingsforcardsthathaveaprogrammabledigitalhybrid.

#hdparm ProgramthatinteractswithLinuxIDEdrivertoobtainandalterdiskparameters

#lsmod Listsinformationaboutallloadedmodules

#lspciv LinuxutilitythatdisplaysinformationaboutdevicesconnectedtothePCIbus,voptiondisplaysIRQallocationdetails#modprobe Addsaloadablemoduletothekernel,e.g.zaptelorwcfxo#psaux Staticsnapshotoverviewofsystemprocesses#setpci UtilityforqueryingandconfiguringPCIdevices#top Dynamicoverviewofsystemprocessesupdatedevery10seconds#uptime CPUloadinformationbasedon5,10,15minuteaverages

#vmstat ProvidesinformationonCPU/memoryusageaswellsystemI/Oinformation

#ztcfgvv Reloadsthezaptel.confconfiguration,"vv"optionprovidesinformationonconfiguredzapchannels#ztmonitor TooltohelpsettheappropriateRX/TXgainvalues

#zttool TheZaptelTool(zttool)commandshowsthecurrentstatusofanyZaptelsupportedinterfacecards

#zttest ZaptelTest(zttest)isatimingtesttodeterminetheaccuracyoftheZapteltimingCLI>exit ExitfromAsteriskCLICLI>reload ReloadAsteriskCLI>zapshowchannels ShowsZapchannelsrecognisedbyAsteriskCLI>zapshowstatus ShowsZapteldevicesrecognisedbyAsteriskCLI>stopnow StopsAsterisk



ConfigurationFileDescriptions

File Description

/etc/inittab Fileusedtoconfigurerunlevelmodes

/etc/zaptel.conf UsedbytheZapteldrivertodefinetherelevantparametersforzaptelsupportedhardwaredevices

/etc/asterisk/zapata.conf UsedbyAsterisktostoreinformationaboutZapteldevicesandthefeaturessupported

/etc/asterisk/zapataauto.conf Automaticallygeneratedbygenzaptelconf,containsZaptelhardwareconfigurationinformationusedbyAsterisk

/etc/asterisk/extensions.conf Containsdialplaninformationintheformofinstructionscalledextensions,whicharegroupedbycontexts

/etc/asterisk/indications.conf Containsinformationaboutthesoundsthataphonesysteminaparticularcountrymakesforvariousindications

/etc/rc6.d/KxxZaptel Zaptelrebootlevelstopscript



9 FurtherAssistance

ThefollowingareusefullinksforIPPBXserverconfiguration:

TrixboxWithoutTearshttp://dumbme.voipeye.com.au/trixbox2/trixbox2_without_tears.pdfElastixWithoutTearshttp://www.elastixconnection.com/downloads/elastix_without_tears.pdfAsteriskInstallationGuidehttp://www.voipinfo.org/wikiAsterisk+installation+tipsTrixboxInstallationGuide http://www.trixbox.org/wiki/trixboxquickinstallguidePBXinaFlashInstallationGuidehttp://pbxinaflash.net/docs/InstallPBXInAFlash1.2.pdf

LinkstotheonlineforumsandwikisforassistanceinstallingAsterisk/Trixboxareprovidedbelow:

AsteriskWiki http://www.voipinfo.org/wikiAsteriskAsteriskForum http://forums.digium.comTrixboxForumhttp://www.trixbox.org/forumTrixboxWikihttp://help.trixbox.com

Forproductinstallationguidesandsupportcontactinformationpleasevisitoursupportpage:

www.novavox.co.uk/support

Novavoxcustomersonly:Ifafterfollowingtheguidanceprovidedonthesupportpageyouareunabletoresolvetheissuethenpleasecontactusatsupport@novavox.co.uk.



AppendixASignallingmethods

Groundstart(gs)

GroundstartsignallingalsoknownasEarthStartandisnotverycommon.ThePBX/phonesignalsacallbyconnectinganearthtooneofthewiresandcurrentflowsfromthePBXearthtothelocalexchangebattery.ThelocalexchangerespondsbysendingdialtonetothePBX/phone.ThelocalexchangesignalsacalltothePBX/phonebyputtinganearthononeofthewires.ThePBX/phonedetectstheearthandlooksforringingvoltagewhichthelocalexchangesends.

Loopstart(ls)

Loopstartsignallingissupportedbythemajorityofanaloguephonelines.InLoopstartsignallingthelocalexchangesignalsacallbysendingringingvoltagetothephone/PBX.Itallowsaphonetoindicateonhook/offhook(andaPBXtoseizetheline)byputtingaloopacrossthewires.Thelocalexchangerespondsbysendingdialtonetothephone/PBX.

Kewlstart(ks)

Kewlstartsignallingworksinthesamewayasloopstart,butitallowsthelocalexchangetodropbattery/voltagemomentarilyonthephonelinetoindicatetothephone/PBXthattheotherendofthepartyhasdisconnectedthecall,i.e.toprovidehangupnotification.ThisvoltagedropisknownasCPC(CallingPartyControl)orDisconnectClearTime(DCT)intheUK.



AppendixBCountrycodes/zones

Code Country/Zoneat Austriaau Australiabe Belgiumbr Brazilch Switzerlandcl Chilecn Chinacz CzechRepublicde Germanydk Denmarkee Estoniaes Spainfi Finlandfr Francegr Greecehu Hungaryil Israelin Indiait Italylt Lithuaniamx Mexiconl Netherlandsno Norwaynz NewZealandpl Polandpt Portugalru Russiase Swedensg Singaporetw Taiwanuk UnitedKingdom/Irelandus UnitedStatesuso UnitedStatesOldve Venezuelaza SouthAfrica



AppendixCZaptel.confconfigurationparameters

busycountBusycountisthenumberofbusytonestodetect,whenbusydetectisenabled.Thelowerthevaluethequickerthecallwillhangup,butthisincreasesthepossibilityoffalsehangups.[positiveinteger]

busydetectWiththisoptionenabled,asteriskwilllistenforbusysignalsontheline,ifyourcarriersendsyouabusytoneonahangup,Asteriskshoulddetectit.ItshouldbenotedthatthisoptionislessreliablethanotherhangupdetectionmethodssuchaspolarityreversalandCPC(CallingPartyControl)soshouldonlybeusedtodetecthangupsiftheothermethodsarenotsupported.[yes/no]

calleridCallerIDcanbesettoasreceivedoraspecificnumberifyouwanttooverrideit.Pleasenotethatasreceivedonlyappliestotrunkinterfaces.[asreceivedoraspecificnumber]

callgroup,pickupgroupSupportsringgroups(a.k.a.callgroups)andpickupgroups.Ifaphoneisringinganditisamemberofagroupwhichisoneofyourpickupgroups,thenyoucanansweritbypickingupusingthepickupcode.Forsimpleoffices,justmaketheseboththesamepositiveinteger.

callprogress,progzoneThisoptionissimilartothebusydetectoption,butwillalsolistenforaringingtone,congestiontoneandwilltrytodetectifthelinegotanswered.However,thisfeatureisexperimentalandcaneasilydetectfalseanswersanderrors.Fewzonesaresupported,butmaybeselectedwithprogzone[yes/no,andtwolettercountrycodeforprogzone].

callreturnSupportcallreturn.[yes/no]

callwaitingEnablecallwaitingonFXOlines.[yes/no]

callwaitingcalleridSetswhethertoreceivecallerIDduringcallwaitingindication.[yes/no]

canparkAllowcallparking.[yes/no]

cidsignallingTypeofcallerIDsignallinginuse.

bell=bell202(US)v23=v23(UK)dtmf=DTMF(Denmark,Sweden,&Netherlands)

cidstartIdentifieswhatsignalsthestartofcallerID.

ring=aringsignalsthestartpolarity=polarityreversalsignalsthestart

contextDefinestheinitialcontextforthechannel.Thiswillbethecontextavailabletothechannelupontheinitiationofacall.Notethatcontextsareanimportantpartofmaintainingsitesecurity.Theinitialcontextwillgoverntheavailabilityofextensionstoagivenchannel.Ifanextensionisplacedinadifferentcontextfromtheinitialcontext,thatextensionisunavailabletothecaller.

echocancelEnableechocancellation.[yes/no,orapoweroftwofrom32to256tosetthenumberofcancellationtaps]

echocancelwhenbridgedGenerally,itisnotnecessary(andinfactundesirable)toechocancelwhenthecircuitpathisentirelyTDM.Youmay,however,reversethisbehaviourbyenablingtheechocancelduringpureTDMbridging.[yes/no]



echotrainingInsomecases,theechocancellerdoesn'ttrainquicklyenoughandthereisechoatthebeginningofthecall.EnablingechotrainingwillcauseAsterisktobrieflymutethechannel,sendanimpulse,andusetheimpulseresponsetopretraintheechocancellersoitcanstartoutwithamuchcloserideaoftheactualecho.[yes,no,oranumberofmilliseconds(102000)todelaybeforetraining]

faxdetectUponfaxdetection,routesfaxtoafaxextension.[Both,incoming,outgoing,orno.]

groupAllowsanumberofchannelstobetreatedasoneforthepurposeofdialing.Fordialingout,thechannelswillbecalledonafirstavailablebasis.Forthepurposeofringingstations,allchannelsinthegroupwillringatonce.Takesanintegerfrom0to63andmultiplegroupscanbespecified.

hanguponpolarityswitchInsomecountries,apolarityreversalisusedtosignalthedisconnectofaphoneline.Ifthisoptionisenabled,thecallwillbeconsidereddisconnectedonapolarityreversal.[yes/no]

hidecalleridSetswhethertohideoutgoingcallerID,defaultstono.[yes/no]

immediateSpecifywhetherthechannelshouldbeansweredimmediatelyorifthesimpleswitchshouldprovidedialtone,readdigits,etc.[yes/no]

musiconholdSelectwhichclassofmusictouseformusiconhold.Ifnotspecifiedthenthedefaultwillbeused.Themusicclassisdefinedinmusiconhold.conffile.[default,loud,random]

pulsedialUsepulsedialinsteadofDTMFforFXO(FXSsignalled)devices.[yes/no]

relaxdtmfIfyouhavetroublewithDTMFdetection,youcanrelaxtheDTMFdetectionparameters.RelaxingthemmaymaketheDTMFdetectormorelikelytohavetalkoffwhereDTMFisdetected.[yes/no]

rxgainAdjustsreceivegain.Thiscanbeusedtoraiseorlowertheincomingvolumetocompensateforhardware/linedifferences.[Positiveornegativedouble,measuredindB]

sendcalleridafterSomecountrieshaveringtoneswithasetofcadenceswhichdifferfromthedefault.Thisrequiresthecalleridtobesetwithadelay,andnotrightafterthefirstring.[Positiveinteger]

threewaycallingSupportthreewaycalling.[yes/no]

transferSupportflashhookcalltransfer(requiresthreewaycalling).Alsoenablescallparking(overridesthecanparkparameter).[yes/no]

txgainAdjuststransmit.Thiscanbeusedtoraiseorlowertheoutgoingvolumetocompensateforhardware/linedifferences.[Positiveornegativedouble,measuredindB]

usecalleridWhetherornottousecallerID.[yes/no]

usedistinctiveringdetectionIndicateswhetherornottoallowdistinctiveringdetectiononFXOlines.[yes/no]



AppendixDRecompilingZaptel

Guidelines

ZaptelSoftwareVersion

DetailedinstructionsareprovidedbelowforrecompilingZaptelversion1.4.10.1,whichistheversionusedinTrixbox2.6.07.IfyouwishtorecompileadifferentZaptelversion,thenyouwillneedtoensureyoucheckwhatZaptelVersioniscurrentlyrunningandmodifytheinstructionstodownload/installthecorrectversion.

ConfigurationFileBackups

UnlesssomethinggoeswrongyourcurrentconfigurationfilesshouldnotbemodifiedwhenrecompilingtheZaptelsoftware.However,itisrecommendedtobackupcurrentconfigurationfilesinjustcasesomethingdoesgoeswrong,particularlyiftheIPPBXisaworkingsystem.

SoftwarePackageDependencies

IfyouyourIPPBXhassoftwarepackagesinstalledthataredependantonZaptel,thenthereisapossibilitythattheymaynotworkproperlyafterrecompilingtheZaptelsoftwareandtheymayneedtobereinstalled.Also,ifyouhaveinstalledanyotherpatchesormodifiedanyoftheoriginalZaptelsourcecode(e.g.tosupportvendorspecifichardwaredrivers)thenyouwillneedtorepeatthesamecodechangesbeforerecompilingtheZaptelcode.

Instructions

Theinstructionsbelowarebasedonusingyumforpackageupdates/installationandwgettodownloadsourcecodetarballs.However,ifpreferredalternativemethodscanbeusedsuchasusingaptormanuallydownloadingrpmstoupdate/installpackagesandusingsvntodownloadsourcecode.

1.UpdatePackages

Itisrecommendedthatyouensurethatallinstalledsoftwarepackagesareuptodateusing:

#yumupdatey

Warning:Ifyouhavepatchedanyinstalledpackagesthenthesewillneedtobepatchedandrecompiledagainafterusingyum.Asanalternative,youcanjustupdatetheZaptelpackageasthisisbeingrecompiledanyway.

2.InstallkernelSourceTree

Firstofallchecktoseeifyouneedtoinstallakernelsourcetreebyrunning:

#lsl/lib/modules/`unamer`/build/.config||echo"Installkernel"

Iftheoutputshows"Installkernelthencheckwhatkerneltypeyouneedasshownbelow,otherwiseproceedtostep3.

Checkifyouareusingasmpkernelornot:

#unamer|grepqsmp&&echo"InstallSMPkernel."

Iftheoutputshows"InstallSMPkernel.",thenrun:



#yuminstallkernelsmpdevelkernely

Otherwiserun:

#yuminstallkerneldevelkernely

3.InstallC/C++CompilerPackages

InstallC/C++CompilerstoCompileSourceCodeifyoudonthavetheminstalledonyoursystem:

#yuminstallgccy#yuminstallgccc++y

4.ShutdownandRestarttheIPPBX

Rebootandcheckthateverythingisstillworkingcorrectlyafterinstalling/updatingrelevantpackages:

#shutdownrnow

DownloadZaptelSourceCode

Changetousersourcecodedirectoryanddownload/unziptherequiredsoftwarepackages:

#cd/usr/src

5.Download/UnzipZaptel

#wgethttp://ftp.digium.com/pub/zaptel/releases/zaptel1.4.10.1.tar.gz#tarxzvfzaptel1.4.10.1.tar.gz#lnszaptel1.4.10.1zaptel

6.MakeSourceCodeModifications

AtthispointyoushouldmaketherequiredchangestotherelevantZaptelsourcecodefiles.Ifyouarechangingthedefaultechocancellationsoftwarethenyoushouldmodifythezconfig.hfileasdescribedinSection5.2.7.

7.StopAsteriskandZaptel

FirstofallstopAsterisk:

#amportalstop/CLI>stopnow

ThenstopZaptel:

#servicezaptelstop

8.RemoveExistingZaptelmodules

ThecommandsbelowarecorrectforremovingtheZaptelmoduledirectoriesinTrixbox2.6.07(theZaptelmodulesmaybeinoneorpossiblybothdirectories).

#rmr/lib/modules/`unamer`/extra/zaptel#rmr/lib/modules/`unamer`/misc



IfyouareusingadifferentTrixboxversionoranalternativeIPPBXpackagethenyouwillneedtofindwheretheZaptelmodulesarecurrentlyinstalled.TofindtheZaptelmodulesdirectoryfindthedirectorythatthewcfxo.komoduleisstored.

Note:AsanalternativetodeletingtheZaptelmoduledirectoryyoucouldmakeacopyofthedirectoriesandthendeletetheoldonestoprovideacontingencyplanifanythinggoeswrong.

9.CompileZaptelSourceCode

CompiletheZaptelSourceCode:

#cd/usr/src/zaptel#makeclean#make

Youshouldreceivethefollowingmessage:

********Theconfigurescriptwasjustexecuted,so'make'needstobe****restarted.****make:***[config.status]Error1

Continuebyrunning:

#make#makeinstall#makeconfig

Thefollowingshouldbeincludedintheoutput:...Ithinkthatthezaptelhardwareyouhaveonyoursystemis:pci:0000:04:06.0wcfxo 1057:5608WildcardX100P

10.ShutdownandRestarttheIPPBX

#shutdownrnow

ConfigurationCompleteTheZaptelsourcecodehasbeenrecompiledandyourIPPBXisnowreadytobeused.



AppendixEAcronyms

Acronym DescriptionACPI AdvancedConfigurationandPowerInterfaceAPIC AdvancedProgrammableInterruptControllerBIOS BasicInput/OutputSystemBT BritishTelecomCLI CommandLineInterfaceCPC CallingPartyControlCPU CentralProcessingUnitCTR21 CommonTechnicalRequirementsdirective21DAA DirectAccessArrangementDCT DisconnectClearTimeDMA DirectMemoryAccessDSP DigitalSignalProcessorERL EchoReturnLevelFCC FederalCommunicationsCommissionFXO ForeignExchangeOfficeFXS ForeignExchangeStation/SubscriberGUI GraphicalUserInterfaceI/O Input/OutputIDE Intelligent/IntegratedDriveElectronicsIP InternetProtocolIPPBX IPPrivateBranchExchangeIRQ InterruptRequestJATE JapanApprovalsInstituteforTelecommunicationsEquipmentOSLEC SourceLineEchoCancellerPCI PeripheralComponentInterconnectPOTS PlainOldTelephonyServicePSTN PublicSwitchedTelephonyNetworkSCSI SmallComputerSystemInterfaceSMP SymmetricMultiProcessingUDMA UltraDMAUK UnitedKingdomUSB UniversalSerialBusVoIP VoiceoverIP

Documents

Novavox Asterisk Card Installation Issues