Basic Troubleshooting Basic Troubleshooting and Maintenance for CS and Maintenance for CS

corecore

Pre-requisitePre-requisite►Basic knowledge of R99 networking Basic knowledge of R99 networking

(GSM) structure.(GSM) structure.

TermsTerms► H.248 link - H.248 link - link between the MSC-Server and the Media Gateway link between the MSC-Server and the Media Gateway

with the use of SCTP.with the use of SCTP.► Media Gateway- Media Gateway- handles the media, or bearer, interface. It converts handles the media, or bearer, interface. It converts

media from the format used in one network to the format required media from the format used in one network to the format required in another network.in another network.

► MGC – MGC – Another name for MSC Server.Another name for MSC Server.► MSC Server – MSC Server – Control Layer of the MSC in the R4 network to realize Control Layer of the MSC in the R4 network to realize

mobility management, call control and media gateway control.mobility management, call control and media gateway control.► SCTP – SCTP – (Stream Control Transmission Protocol) a SigTran transport (Stream Control Transmission Protocol) a SigTran transport

protocol used for the H.248 link. A transport protocol which carries protocol used for the H.248 link. A transport protocol which carries SS7 application messages over IP with high-reliability.SS7 application messages over IP with high-reliability.

R4 NetworkingR4 Networking► MSC is divided into two network elements which MSC is divided into two network elements which

handles corresponding layershandles corresponding layers► MSC Server handles the control layer (signaling)MSC Server handles the control layer (signaling)► Media Gateway handles the bearer layer (voice, Media Gateway handles the bearer layer (voice,

data and other media stream). It also has the data and other media stream). It also has the function of a signaling gateway (STP).function of a signaling gateway (STP).

► Inherit all R4 featuresInherit all R4 features► Introduce IP multimedia subsystemIntroduce IP multimedia subsystem► Introduce HSDPAIntroduce HSDPA► Iu Interface ( Interface between MSS Iu Interface ( Interface between MSS

and RNC ) can be IP based or ATM and RNC ) can be IP based or ATM based.based.

R5 NetworkingR5 Networking

Summary:Summary:

► Introduction of R4 and R5 evolutionIntroduction of R4 and R5 evolution►Our emphasis on the CS Core training Our emphasis on the CS Core training

is the R4 networking.is the R4 networking.

Signaling and SS7Signaling and SS7

► ACM – a SS7 (ISUP) signaling message which indicates that the IAM from the originating ACM – a SS7 (ISUP) signaling message which indicates that the IAM from the originating switch has reached the destination switch and was properly analyzed. The latter then switch has reached the destination switch and was properly analyzed. The latter then sends back a ring back tone or play an announcement.sends back a ring back tone or play an announcement.

► ANM – a SS7 (ISUP) signaling message which indicates that the destination switch of the ANM – a SS7 (ISUP) signaling message which indicates that the destination switch of the called party has answered the requested call.called party has answered the requested call.

► BICC - (Bearer Independent Call Control) developed based on the ISUP protocol. The BICC - (Bearer Independent Call Control) developed based on the ISUP protocol. The session and bearer are separated through the BICC protocol; thus the call service function session and bearer are separated through the BICC protocol; thus the call service function (CSF) and bearer control function (BCF) are independent. Voice circuits are established (CSF) and bearer control function (BCF) are independent. Voice circuits are established between MSS and does not require the function of a MGW.between MSS and does not require the function of a MGW.

► CAP – a signaling protocol used in GSM between a Service Switching Point (MSC) and a CAP – a signaling protocol used in GSM between a Service Switching Point (MSC) and a Service Control Point ( IN, HLR etc.). Used for prepaid, special services etc.Service Control Point ( IN, HLR etc.). Used for prepaid, special services etc.

► Global Title (GT) – an international title given to a network element for the purpose of Global Title (GT) – an international title given to a network element for the purpose of interworking with other network elements with or without direct signaling interconnection.interworking with other network elements with or without direct signaling interconnection.

► IAM – a SS7 (ISUP) signaling message which indicates an initial transaction being queried IAM – a SS7 (ISUP) signaling message which indicates an initial transaction being queried by originating switch to the destination switch. The message contains the A and B number, by originating switch to the destination switch. The message contains the A and B number, number of trunk circuit that is initially used and other information beyond the scope of this number of trunk circuit that is initially used and other information beyond the scope of this explanation.explanation.

► ISUP – (ISDN User Part) a SS7 protocol used in the establishment and tear down of voice ISUP – (ISDN User Part) a SS7 protocol used in the establishment and tear down of voice and data calls between two switches.and data calls between two switches.

TermsTerms

► Link – logical interconnection between two network elements where signaling Link – logical interconnection between two network elements where signaling messages are sent and received.messages are sent and received.

► Link Set - a set of signaling links between two network elements.Link Set - a set of signaling links between two network elements.► M2PA – (MTP level 2 peer to peer adaptation) a SigTran protocol to realize the SS7 M2PA – (MTP level 2 peer to peer adaptation) a SigTran protocol to realize the SS7

function of MTP2 over IP. Similar to M2UA, the difference is that both NE associated function of MTP2 over IP. Similar to M2UA, the difference is that both NE associated with this type of protocol requires a signaling point code. Used between STPs in our with this type of protocol requires a signaling point code. Used between STPs in our networknetwork

► M2UA - (MTP level 2 user adaptation layer) a SigTran protocol to realize the SS7 M2UA - (MTP level 2 user adaptation layer) a SigTran protocol to realize the SS7 function of MTP2 over IP. Used commonly when interworking with BSCs.function of MTP2 over IP. Used commonly when interworking with BSCs.

► M3UA - (MTP level 3 user adaptation layer) a Sigtran protocol to realize the SS7 M3UA - (MTP level 3 user adaptation layer) a Sigtran protocol to realize the SS7 function of MTP3 over IP. Used between MSS to MSS and MSS to STP connection in function of MTP3 over IP. Used between MSS to MSS and MSS to STP connection in our network.our network.

► MAP – (Mobile Application Part) a protocol used in GSM for subscribers’ services, MAP – (Mobile Application Part) a protocol used in GSM for subscribers’ services, profiles, mobility management and call control.profiles, mobility management and call control.

► MSISDN – (Mobile Station Integrated Services Digital Network) the mobile MSISDN – (Mobile Station Integrated Services Digital Network) the mobile subscriber’s directory number. The number that is known to a common subscriber.subscriber’s directory number. The number that is known to a common subscriber.

► MSRN – (Mobile Station Roaming Number) is a temporary number allocated to a MSRN – (Mobile Station Roaming Number) is a temporary number allocated to a called subscriber by its serving VLR/MSC.called subscriber by its serving VLR/MSC.

► Point Code – an identifier of a network element in a SS7 network.Point Code – an identifier of a network element in a SS7 network.► REL – an SS7 (ISUP) message sent by the called switch to the originating switch to REL – an SS7 (ISUP) message sent by the called switch to the originating switch to

indicate that the call has been released.indicate that the call has been released.► SCCP – (Signaling Connection Control Part) SCCP – (Signaling Connection Control Part) The SCCP provides additional network layer The SCCP provides additional network layer

functions to provide transfer of noncircuit-related (NCR) signaling information, application functions to provide transfer of noncircuit-related (NCR) signaling information, application management procedures and alternative and more flexible methods of routing. management procedures and alternative and more flexible methods of routing.

► Signaling – exchange of call components between network elements required to Signaling – exchange of call components between network elements required to provide and maintain service. provide and maintain service.

► STP – (Signaling Transfer Part) a network element which receives and routes STP – (Signaling Transfer Part) a network element which receives and routes signaling messages towards the proper destination.signaling messages towards the proper destination.

MGw1MGw1MGw 7GCC B1MGw1MGw1MGw1MGw1MGw 7GCC B1

MSCMSCMSS 5

MSCMSC…MSCMSCMSS 1

MSCMSCMSS 5MSCMSCMSCMSCMSS 5

MSCMSC…MSCMSCMSCMSC…MSCMSCMSS 1MSCMSCMSCMSCMSS 1

MGw1MGw1MGw 1CebuMGw1MGw1MGw1MGw1MGw 1Cebu

MGw1MGw1MGw 2CebuMGw1MGw1MGw1MGw1MGw 2Cebu

MGw1MGw1MGw 5

MGw1MGw1….

MGw1MGw1MGw 3

MGw1MGw1MGw 5MGw1MGw1MGw1MGw1MGw 5

MGw1MGw1….MGw1MGw1MGw1MGw1….

MGw1MGw1MGw 3MGw1MGw1MGw1MGw1MGw 3

MGw1MGw1MGw 6CebuMGw1MGw1MGw1MGw1MGw 6Cebu

MGW13H

GMSS1H

GCC B1

GMGW1H

GCC B1

GMGW2H

Pioneer new

GMSS2H

Pioneer new

GMSS1H

GCC B1

GMSS1H

GCC B1

GMGW1H

GCC B1

GMGW2H

Pioneer new

GMSS2H

Pioneer new

GMSS2H

Pioneer new

MSS13HMSS11H

…….MSS2H

MSS1H

MSS13HMSS13HMSS11HMSS11H

…….…….MSS2HMSS2H

MSS1HMSS1H

MGW12H…….

MGW2HMGW1H

MGW12H…….

MGW2HMGW1H

G/TMGW_6HG/TMGW_6H

NCRNCRJGJG

880K880K

G/TMSC2G/TMSC2

GCC (B2)GCC (B2)

G/TMGW_6HG/TMGW_6H

NCRNCRJGJG

880K880K

G/TMGW_6HG/TMGW_6H

NCRNCRJGJG

880K880K

G/TMSC2G/TMSC2

GCC (B2)GCC (B2)

G/TMSC1G/TMSC1

Libis (new)Libis (new)

G/TMSC1G/TMSC1

Libis (new)Libis (new)

G/TMSC1G/TMSC1

Libis (new)Libis (new)

InternationalPSTN

OPLMN

InternationalPSTN

OPLMN

STM1

STM1

Current DMPI Architecture

…NCR MSC

…SLZ MSC

…NLZ MSC

…VSIMIN MSC

GMSC

…HLR

SG3/4 SG1/2

IN-SCP SMSC USSDSGSN GEMPLUSAIP STARHOMERCP 1 RCP 5/6

FINAL SIGNALING NETWORK STRUCTURE – PHASE 8A

Call FlowCall Flow

►Mobile to Mobile CallMobile to Mobile Call►Mobile to Mobile Call (PRBT sub)Mobile to Mobile Call (PRBT sub)►Mobile (prepaid) to Mobile callMobile (prepaid) to Mobile call►Mobile to PSTNMobile to PSTN►PSTN to MobilePSTN to Mobile►SMS MO and MTSMS MO and MT

SummarySummary

► Introduction to SS7 and SignalingIntroduction to SS7 and Signaling►How SS7 is applied in our current How SS7 is applied in our current

networknetwork►How SS7 messages are used in a call How SS7 messages are used in a call

flowflow

Introduction to LMT tool and basic command Introduction to LMT tool and basic command handlinghandling

Steps for using trace messageSteps for using trace message

► After logged on the desired MSS, click on the maintenance tab at the After logged on the desired MSS, click on the maintenance tab at the lower left of the window.lower left of the window.

► Select what type of trace is to be conducted. Most of the time, User Select what type of trace is to be conducted. Most of the time, User message trace is selected. Double click on User Message trace, a pop message trace is selected. Double click on User Message trace, a pop up window should appear on the center of the screen.up window should appear on the center of the screen.

► On the pop up window, Select MSISDN number for User Input box (if On the pop up window, Select MSISDN number for User Input box (if tracing in VMSC) and type the mobile number being traced in the tracing in VMSC) and type the mobile number being traced in the MSISDN box. For the Combination, choose select all meaning all MSISDN box. For the Combination, choose select all meaning all interfaces that were used by the call flow will be traced.interfaces that were used by the call flow will be traced.

► On the pop up window, Select PSTN number for User Input box (if On the pop up window, Select PSTN number for User Input box (if tracing in TMSC) and type the number tracing in TMSC) and type the number sent by the originating sent by the originating MSS in the IAM messageMSS in the IAM message, being traced in the PSTN box. For the , being traced in the PSTN box. For the Combination, choose select all meaning all interfaces that were used Combination, choose select all meaning all interfaces that were used by the call flow will be traced.by the call flow will be traced.

Most encountered problemsMost encountered problems

►Sun cannot call landline numbersSun cannot call landline numbers►Suntel cannot call landline numbersSuntel cannot call landline numbers

ProceduresProcedures► Trace first the caller of the roaming VMSC, then call the unreachable Trace first the caller of the roaming VMSC, then call the unreachable

landline number. landline number. ► Note in the trace message, blue lines indicate messages being sent by Note in the trace message, blue lines indicate messages being sent by

the switch being traced while black lines indicate replies of interacting the switch being traced while black lines indicate replies of interacting NEs.NEs.

► Check in the trace message for the BICC_TYPE_IAM message.Check in the trace message for the BICC_TYPE_IAM message. All calls of SUN to other PSTN numbers are routed towards TMSC1H and 2H All calls of SUN to other PSTN numbers are routed towards TMSC1H and 2H

while TMSC1H only for Suntel.while TMSC1H only for Suntel. If BICC_TYPE_IAM message is present, And the called and the calling number If BICC_TYPE_IAM message is present, And the called and the calling number

is in the correct format, the next step is to trace in TMSCs.is in the correct format, the next step is to trace in TMSCs. If the BICC_TYPE_IAM message is not present and the DISCONNECT message If the BICC_TYPE_IAM message is not present and the DISCONNECT message

is present in the trace rather, then the problem is in that VMSC.is present in the trace rather, then the problem is in that VMSC. In the MML command line, run the command LST CNACLD, check for the In the MML command line, run the command LST CNACLD, check for the

longest prefix defined in the VMSC that matches the called number (if the longest prefix defined in the VMSC that matches the called number (if the caller is SUN, check for DN SET=0, if Suntel check for DN SET=88)caller is SUN, check for DN SET=0, if Suntel check for DN SET=88)

If there is no call prefix that does not match the called number, even a single If there is no call prefix that does not match the called number, even a single digit, then definition should be done by NACM.digit, then definition should be done by NACM.

If there is a call prefix that matches the called number but has wrong If there is a call prefix that matches the called number but has wrong parameters, then modification should be done by NACM.parameters, then modification should be done by NACM.

TMSC traceTMSC trace

► BICC_TYPE_IAM message should be sent by the VMSCBICC_TYPE_IAM message should be sent by the VMSC► If IAM message is sent to our switch counterpart which has direct If IAM message is sent to our switch counterpart which has direct

interconnection to Huawei Transit MSS (e.g. GCCT7, BNLN7, BALS7, GLOB, interconnection to Huawei Transit MSS (e.g. GCCT7, BNLN7, BALS7, GLOB, IGF1, IGF2, IGF3, ETP07, BYNT7), and ACM is not received and REL message is IGF1, IGF2, IGF3, ETP07, BYNT7), and ACM is not received and REL message is received rather.received rather.- Check in the IAM message if TMSS can send the correct A and B number - Check in the IAM message if TMSS can send the correct A and B number format.format.- If correct, then the problem is in our switch counterpart.- If correct, then the problem is in our switch counterpart.- If incorrect, then modification should be done by NACM.- If incorrect, then modification should be done by NACM.

► If IAM message is sent to our Alcatel Gateways and ACM is not received and If IAM message is sent to our Alcatel Gateways and ACM is not received and REL message is received rather.REL message is received rather.- Check in the IAM message if TMSS can send the correct A and B number - Check in the IAM message if TMSS can send the correct A and B number format.format.- If correct, then the problem should be endorsed to Core OPTI group since - If correct, then the problem should be endorsed to Core OPTI group since they are capable in tracing messages in Alcatel gateways.they are capable in tracing messages in Alcatel gateways.

Immediate Data ModificationImmediate Data Modification

Rerouting of TrafficRerouting of Traffic

► Prerequisite – the secondary switch, where the traffic is to be rerouted, allows, Prerequisite – the secondary switch, where the traffic is to be rerouted, allows, can process and route the call to the same operator, with their Gateway can process and route the call to the same operator, with their Gateway switch switch

► Steps:Steps:1. Backup existing data. Run LST CNACLD1. Backup existing data. Run LST CNACLD2. Check for the route of the original and the secondary route to be used. Run 2. Check for the route of the original and the secondary route to be used. Run

LST RTANA.LST RTANA.3. Modify the route of the call prefixes. Run MOD CNACLD.3. Modify the route of the call prefixes. Run MOD CNACLD.

Signaling Link Reallocation for BSCsSignaling Link Reallocation for BSCs

TermsTerms

► CIC – (Circuit Identity Code) a SS7 code used to identify a unique voice circuit CIC – (Circuit Identity Code) a SS7 code used to identify a unique voice circuit between two officesbetween two offices

► Integer Interface ID – a identifier parameter of the M2UA link when Integer Interface ID – a identifier parameter of the M2UA link when interworking with MSS and MGW.interworking with MSS and MGW.

► SLC – (Signaling link Code) a SS7 code used to identify a unique signaling link SLC – (Signaling link Code) a SS7 code used to identify a unique signaling link between two offices.between two offices.

► TID – (Terminal Circuit ID) unique circuit ID that identifies a voice circuit in a TID – (Terminal Circuit ID) unique circuit ID that identifies a voice circuit in a MGWMGW

► Office - a network element which has voice circuits.Office - a network element which has voice circuits.

StepsSteps

► Identify which CIC will cater the reallocated signaling link. The CIC that will Identify which CIC will cater the reallocated signaling link. The CIC that will cater the reallocated signaling link should be the same in MSC and BSCcater the reallocated signaling link should be the same in MSC and BSC

► In MSS, run LST OFCTKC put in the office direction name parameter the office In MSS, run LST OFCTKC put in the office direction name parameter the office name of the NE that needs reallocation. Check the TID of the corresponding name of the NE that needs reallocation. Check the TID of the corresponding CIC.CIC.

► In MGW run LST TDMTID, put the TID value in the TID(DEC) parameter, it will In MGW run LST TDMTID, put the TID value in the TID(DEC) parameter, it will display the hardware position of the device (Frame no., Slot no., port no.)display the hardware position of the device (Frame no., Slot no., port no.)

► Go to the device panel and search for the position given by the above Go to the device panel and search for the position given by the above command. Get the board no.command. Get the board no.

► After getting the board no and the port no, run DSP CFG to check the existing After getting the board no and the port no, run DSP CFG to check the existing configuration of the desired link to be reallocated. configuration of the desired link to be reallocated.

► To modify the link run RMV MTP2LNK then ADD MTP2LNK, obtain all To modify the link run RMV MTP2LNK then ADD MTP2LNK, obtain all parameters the same except for the board no and port no.parameters the same except for the board no and port no.

► After modification done check the status of the link in MSS. Run DSP N7LNK, After modification done check the status of the link in MSS. Run DSP N7LNK, the status should be healthy and in use.the status should be healthy and in use.

Trunk Test Call for BSCsTrunk Test Call for BSCs

NeedsNeeds

► Prior to commercialization of additional A – interface circuits, Prior to commercialization of additional A – interface circuits, (E1 circuits between MSC and BSC) it should have excellent (E1 circuits between MSC and BSC) it should have excellent voice qualityvoice quality

► To test E1s with possible echo and crosstalkTo test E1s with possible echo and crosstalk

ProceduresProcedures

► Get the CICs of the E1 circuits to be tested.Get the CICs of the E1 circuits to be tested.► Check for the location of the A and B number to be used as Check for the location of the A and B number to be used as

test numbers. Both of them should be catered by the same test numbers. Both of them should be catered by the same BSC where the circuits are to be tested.****BSC where the circuits are to be tested.****

► Decide how many test calls should be made per E1 ( 2 test Decide how many test calls should be made per E1 ( 2 test calls are being done most of the time )calls are being done most of the time )

► Run the command ADD TKTESTRun the command ADD TKTEST► Open a user message trace and enter the MSISDN of the A or Open a user message trace and enter the MSISDN of the A or

B number. A number should dial 139*(b number w/o 0) Check B number. A number should dial 139*(b number w/o 0) Check the message CC_Refresh_Test_Task, the CIC of the test call the message CC_Refresh_Test_Task, the CIC of the test call made should be displayed.made should be displayed.

► Continue the test call until all E1s are tested.Continue the test call until all E1s are tested.