AXE Question

AXE OPERATION & MAINTENANCE DISHNET WIRELESS LTD

PREPARED BY PRASANTA KUMAR BASTIA

Regional Processor(RP) & Extension Module(EM) 1> Name two levels of AXE Ans: APT & APZ. 2> Define APZ Ans: Control part of AXE 3> Define APT Ans: Switching part or telephony part. 4> Define structure of Command Code of AXE Ans: XXYYZ XX-Function group YY-Functional division within a group Z-Task Type 5> Define Winfiol Ans: It is a communication program designed for installation, testing and maintenance of customer exchange. 5> Define RP Ans: RPs belong to the RPS(Regional processor subsystems) .They are links between the CP(central processor) & APT devices (EM). 7> What does RPs consist of ? Ans: a)RPH-Regional processor handler in CPs b) RPB(Regional processor bus) c) Various Regional Processors 8> Define function of RPH Ans: a) To offer an interface to the RP Buses. b) Temporarily store the information to and from the CP and load the traffic on the RP buses. 9> Define RPB Ans: It is a bus connecting the CP with the RPs. 10> Define types of RPBs Ans: a) RPB –P (Parallel) b) RPB-S (Serial) 11> Define EM Ans: An EM is the smallest control unit in the system. It consists of a well defined number of APT devices.

12> Define EMB (EM bus) Ans: EMs are connected to RPs through EMB. 13> Who controls hardware of EM? Ans: RP 14> How the capacity of RP is expressed? Ans: Capacity of RP is expressed in terms of number of EMs. One RP controls even number of EMs and other RP controls odd number of EMs. 15> Define types of CP. Ans: In normal operation, CP-A is executive & CP-B is the standby working (SBWO). 16> Commands for defining RP Ans: a) Defining of an RP EXRPI:RP=120, RPT=121, TYPE=RP4S1A; RPT-Twin RP b) Blocking of RP BLRPI: RP= ; c) Deblocking of RP BLRPE: RP= 256&257&260&261&264&265; d)Software unit loaded into the RP EXRUI:RP=71, SUID="9000/CXC 146 44 R2C01"; EXRUI: RP= , SUNAME= , SUID= “ “ ; SUNAME-Software unit name SUID- Version of software 17> Full name of GDM Ans: Generic Device Magazine 18> Check data of RP Ans: EXRPP:RP=all; EXRUP:RP=all; 19> Command for remove RP pair. Ans: EXRPE 20> Command to define EM Ans:a)EXEMI:RP= , RPT= , EM= , EQM= ; EQM-Equipment type and identity of the devices in the EM EXEMI:EQM=ETBL1-0&&-31,RP=90, RPT=91, EM=2, SUID="1/CAA 105 1487/ETBL1 R1A08"; b) Deblocking of EM ( EM is put into service) BLEME:RP=88, RPT=89, EM=0; 21> Command to block EM Ans:BLEMI

Routes 1> Define different type of Routes Ans: a) External route---Routes to other exchanges b) Internal route---Routes to code sender and announcement machines c) Software routes---Routes to subscriber services or routes for register individuals

2> Command to define route data in exchange Ans: EXROI:R= , dety= , FNC= , SI= , SP= ; Dety(device type)-Type of devices used in the block Route name should be of 7 letter FNC(Function code) –Indicate function of the Route(Traffic direction of Route) 3> Command when more route data is to be assigned to the route Ans: EXRBC 4> Parameters of EXRBC Ans: a)R1-Register signaling route b)RG-Route group c)RO-Origin for route analysis d) PRI-Priority e)MB- Modification of B number (to add or delete digits from B number) f) TTRANS-Transmission characteristics(for connection of 64 kbps digital) 5> Command for deblocking of Route Ans: BLORE: R= ; 6> Command for blocking of Route Ans:BLORI:R= ; 7> What is the step before blocking any route ? Ans: By blocking all devices in the route 8> Command blocking device Ans: BLODI:DEV= ; 9> Command foe deblocking device Ans: BLODE: DEV= ; 10> Command to check block route Ans: BLORP; 11> Command used to add devices in route Ans:EXDRI: R= , DEV= ; 12>Steps for connecting devices in route Ans: a) EXDRI: R= , DEV= ; b) Devices taken into service EXDAI: DEV= ; c)Deblocking of devices BLODE: DEV= ; 13>Command to check devices connected to route Ans:EXDEP: DEV= ; 14>Command to print RP & EM to identify devices in route Ans:EXDRP:DEV= ; 15>Command for state route survey print or state of the devices in a route Ans:STRSP:R= ; NDV—Total number of devices in the route NOCC—Number of busy devices NIDL—Number of idle devices NBLO—Number of blocked devices 16>Command for blocking supervision in Route

Ans:a)BLURC:R= ,LVB=10&20&30,ACL= ; LVB—Limit value for blocking .Indicates the maximum number of Blocked devices in the route. ACL—Alarm Class A1-If number of blocked devices exceed 30 A2-If number of blocked devices between 20 & 30 A3-If number of blocked devices between 10 & 20 b)Disconnect blocking supervision BLURE:R= ; c)Reconnect the blocking supervision BLURI:R= ; d)To check supervision data BLURP:R= ; 17>Command for disturbance supervision of devices Ans:a)DUIAC:R= ,ADL= ,ACL= ; ADL—Allowed disturbance level(in percent) b)Print out of loaded data DUISP:R=all; 18>Command for disturbance supervision of routes Ans:a)DUDAC:R= , ADL= , ACL= ; b)Print out of loaded data DUDAP:R=all; 19>Command for seizure quality supervision of devices Ans:a)To supervise the ratio of Number of seizures --------------------------Number of normal calls Minimum duration of normal call=60sec SEQAC:CTIME= ; CTIME—Normal conversion time in sec b)SEQAC:R= , ACL= ,QUOS=30, QUOB=60; QUO—Quotient B—Blocked c)Print out of specified data SEQAP:R=all; 20>Command for groups for seizure quality supervision Ans: a)SEQGI:R= ; b)SEQGP:all; c)SEQGC:R= ; 21>Command for seizure supervision of trunks Ans:a)SETAC:PL= ,ACL= ; PL—Period length in number of days b)SETAP; 22>When seizure is registered ? Ans:when B answer is received.

SNT(Switching network terminal) & DIP(Digital path) 1>Where SNT presents ? Ans: In group switch(GS).Hardware units are connected to GS . 2>Command for connection of SNT in GS. Ans:NTCOI:SNT= ,SNTP= ,SNTV= ; SNTP(SNT point)---Hardware position of the connection SNTV(SNT variant)—indicates the magazine type used NTCOI:SNT=ASDS3-0,SNTV=33044,SNTP=MUX3-0-4; 3>Command to test SNT Ans: NTTEI:SNT=CCDSNT-0 ; nttei:snt=ECP5-25 ; 4>Command to deblock SNT Ans: NTBLE:SNT=ECP5-0; 5>Command to connect devices to the SNT Ans:EXDUI:DEV ; EXDUI:DEV=UPD1-768&&-799,SNT=ET1551-0, SNTINL=24; 6>Command to check SNT state Ans: NTSTP:SNT=all; 7>Command for connection of DIP Ans:a)DTDII:DIP= , SNT= ; DTDII:DIP=120UPD1, SNT=ET1551-1, DIPP=57; b)Initial data se tting of DIP DTIDC: c)DIP fault supervision DTFSC 8>Command to check quality supervision of DIP Ans:DTQSP:DIP= ; 9>Command to check fault supervion of DIP Ans:DTFSP:DIP= ; 10>What are the different quality supervion parameter of DIP ? Ans:Slip frequency Disturbance frequency Errored second Severely Errored second 11>What is operating speed of ET155(STM-1) Ans:155Mbps 12>Which interface is used for connection of ET155 with GS ? Ans: DL-3 13>Name type product of AXE Ans: BYB 501 14> MSP(Multiplexer section principle ) 1+1 principle Ans:

MS-0 VC12

VC4 MS-1

MS-0 & MS-1 are two layers of any ET155 MS—Multiplexer section 15>What is synchronization source for the clock system in GS ? Ans:Internal 8 KHZ synchronization signal is used 16>What is version of GS clock ? Ans: GS890 17>How software is structured in SNT ? Ans:The software is structured with functional blocks. 18>Different type of functional blocks in AXE Ans: Command block Application block Hardware owning block Interface block

Size Alteraton 1>Define size alteration Ans:Size alteration is the name of the function used to change the file sizes in the Data store of the CP 2>Give some examples of changes that only affect software Ans:a)At the time of traffic intensity(Erlang) is increasing in the exchange b)Increasing subscriber services c)when increasing size of analysis tables 3>Explain different type of size alterations in AXE Ans:a)Global size alteration event These events will affect files in more than one block. Ex:Number of routes in the exchanges b)Local size alteration event These events will affect one block in the exchange. Ex:Number of devices inside one block Global Events Local events APT:000-299 APT:500-799 APZ:300-499 APZ:800-999 4>Command to increase the files in a size Ans:SAAII:SAE= ,BLOCK= , NI= ; NI(Number of individuals)---total number of records after change saaii:sae=529,block=etbl1,ni=2; 5>Command to decrease the file sizes

Ans:SAADI 6>Command to print number of individuals currently defined Ans:SAAEP saaep:sae=all,block=etbl1; 7>Command used to set active or passive the automatic size alteration Ans:SAOCS 8>What is the name of table for system defined ? Ans:SAACTIONS 9>What is use of table SAACTIONS ? Ans:In alarming situations a list of SAE appears whose size needs to be increased. DBTSP:TAB=SAACTIONS;

Analysis 1>Types of Analysis Ans:Route Analysis Charging Analysis B-Number Analysis 2>Explain general principle of traffic analysis Ans:

Analysis Table 1 External data

Analysis Table 2 result RC

B number result Internal data

internal data

Subscriber Category

route data

Inputs to analysis table are a)external data—such as B-number digits or A-number digits b)internal data—subscriber category c)results from other analysis table i.e.RC

Route Analysis 1>Explain inter working between the functional blocks RE(block registers) and RA(Route analysis)

Ans: Block RE Registers

B number 1

Block RA 5

from other block

Route Analysis table

4 2 2 2 2

3

B number analysis table

Block DA a)The b-number from another block is sent to register for storage b)The digits are sent to block digit analysis table DA , for analysis which contains B number analysis table. c) The output of block DA is RC which is sent to block RE for storing d)The RC is sent to block RA . The route analysis table in RA decides route e)The identify of route is sent to RE 3>Parameters of route analysis table Ans: a)RC(Routing case) b)BR(branching) c)Routing program—PO1=1 d)SP(Sending program)-It indicates when an outgoing device is to be seized. 4>Explain digits in SP Ans: SP=553 5---After reception of 5th digit O/G device in the indicated route is seized 5---After reception of 5th digit , seizure signal is sent

3---First digit is to be transmitted is the 3rd 5>Use of following commands ANRSI , ANRSE , ANRPI , ANRZI , ANRAI , ANRAR Ans: ANRSI—specifies new RC in NOP area ANRSE—Deletes RC from OP area ANRPI—Initiates procedure ANRPE—Ends on procedure ANRZI—Clears NOP ANRAI—Activates RC ANRAR—Deactivates RC 6>Explain OP table Ans: Table at which actual analysis is done 7>Explain NOP table Ans: Table which performing changes 8>What are different methods for call charge ? Ans:a)Pulse Metering(PM)—Pulse generated will be stepped b)Toll ticketing(TT)---Total start and end time of call is used.

B Number analysis table 0> Command to define B number Anbsi: b=30-06742,d=4-1,bnt=4,RC=407,cc=0,L=11;(BSNL Bhubaneswar Landline) Anbsi:b=30-094170,d=4-0,bnt=4,rc=2,cc=0,L=11;(BSNL Mobile through L-1 tax) Anbsi:b=30-001241,d=5-0,bnt=1,RC=2,CC=0,L=12-23;(ISD Code through L-1 Tax)

1>What are received from B-number analysis table Ans: RC (Routing case ) & CC(charging case) 2>What is B-number ? Ans: B=Origin----------------B number 3>What is F/N ? Ans:F—First(analysis is started from the first digit in the origin) N—Next(analysis is started from the next digit) 4>What is L ? Ans: L=9-12 (default value is 9-15) L is number length of B number 9---minimum length after that channel will sieze 12—Maximum length after that channel will not seize 5>What is BNT(B number type) ? Ans: map the ISUP indicator(nature of address) Application information –TON BNT=4(national significant number) 6>What is D(destination type) Ans: D=d1-d2 7>What is F ? Ans:First digit use stated origin F=OR First digit strat analysis in original origin This indicates that pre-analysis must be done. 8>What is M ?

Ans:Modification information M=a-b a----Number of digits to remove b---Digits to add 9>What is NAPI ? Ans: Numbering plan indicator 10> Whaqt is TRD ? Ans: Traffic destination code 11>Access barring data Ans: ANDSP; TDCL—Trunk discrimination class D

MTP(Message Transfer Part) 1>Different signaling systems Ans:a)Channel associated signaling(CAS) b)Common channel signaling(CCS) 2> Explain CAS Ans: Transit Exchange

Sub A

Signalling→→ Ex-A

Speech →→

Sub B Ex-B

Signaling and speech always take the same way. Ex: R2MFC In each PCM 16TS is used to provide signaling capacity. 2>Explain CCS Ans:

Transit Exchange

signaling

Sub A

Sub B Ex-A

Speech →→

Ex-B

Signaling and speech always do not take the same way. One signaling link can convey the signaling message for many ckts. Some PCM links have a channel dedicated for signaling which serves traffic channel on many PCM links. 4>Explain general structure of C7 signaling system. Ans: Two parts TUP(Telephone User part) a)UP(user part) IUP(ISDN user part) b)MTP(Message Transfer part) 5>Explain function of UP Ans: a)Ups are responsible for writing and interpreting messages b)At the set up of O/G call , traffic processing function will order a UP to write a message to the exchange receiving call Sub A

Ex A Ex

Ex EXB B

A

Traffic processing

TUP

Trafic Proceesing

TUP

MTP

6>Explain function of MTP Ans:MTPs are used to send messages through the signaling network 7>Explain layered structure of C7 signaling system. Ans: Layer 4---TUP & IUP (software) Layer 3--- Signaling n/w function and signaling message handling(software) Layer 2--- Signaling link function (hardware & software)

Sub B

Layer 1---Signaling data link i.e. SDL (hardware) MTP---layer 1, 2 , 3 8>Explain layer 1 of C7 signaling system. Ans:It is a transmission equipment of 64kbps channel. Hardware used—ETC , PCD(Pulse code device digital) ,Semipermanent connection through GS 9>Explain Layer 2 of C7 signaling system. Ans:It ensures that the signaling messages are delivered over signaling data link. Hardware used---Signaling terminal(ST) from RPG3 card 10>Explain Layer 3 of C7 signaling system. Ans:a)It is used to make sure that the message is delivered to the current UP b)Handle problems in signaling network Ex:Link failure & congestion 11>Define SP(signaling point) Ans:Signaling links (LS) of signaling n/w are called SP. SPs are sources and sinks of signaling traffic. These are n/w nodes. SPs are identified by codes. 12>Function of signaling link(SL) Ans:SL is used for connecting exchanges. SL consists of SDL and its transfer control function. Routing of SL between two SPs can differ 13>Explain SLC(Signaling link code) Ans: All the SLs between two SPs are combined in a SLC. 14>Define Signaling Transfer point(STP). Ans:C7 messages just passes through STP.It switches signaling messages from one Node to other. 15>Define OPC(Originating point code) Ans:The signaling point where the message is composed 16>Define DPC(destination point code) Ans:The signaling point where the message is analysed. 17>How the exchange in the signaling n/w is defined ? Ans: X------------Y X-N/W indicator 0-International signaling n/w 2 or 3 –national signaling n/w Y-SPC(signaling point code) 18>Explain C7 message structure Ans: In C7 signaling system , the signaling information is sent as data packets. These packets are called SU(signaling unit).MTP transports message in SU The most signaling unit is called MSU(Message signal unit) MSU:--MTP transfers user messages F

CK

SIF:-

SIF

SIO

LI

Error correction

F

User info

Label

Label:CIC

OPC

DPC

F-Flag(Signal units separate from one another by start & end flag) CK-Check sum(used for checking correct transferring of signal unit without error) . SIO(service information octet):-contains service indicator & n/w indicator. SIF-Signaling information field(contains actual user messages & address) LI-Length indicator CIC-Circuit identification code 19>Explain hardware of C7 signaling in AXE Ans:ST(Signaling terminal ) in RPG3 card 20>Command to define own SP Ans: C7OPI:OWNSP= ; C7PNC:OWNSP= , SPID= ; 21>Command to define SP of other exchange Ans:C7SPI:SP= ; C7PNC: SP= , SPID= ; 22> Define LS(link set) Ans: It is a signaling path between two exchanges, containing one or more Signaling links. 23>Command for defining link set Ans:C7LDI:LS=2-8115; 24>How to define supervision data of link set? Ans: C7SUC:LS= , LVA=2, ACL=A1; LVA-Minimum number of available signaling links in the LS 25>How to define destinations in the signaling n/w ? Ans: C7RSI:DEST=2-8115,LS=2-8115, PRIO=1; Supervision of destination— C7RUC:DEST=2-8115,ACL=A1; 26>How to tie signaling link to defined LS ? Ans: C7SLI 27>Define signaling route Ans: The route defined for the signaling between an originating point & a destination point is called signaling route. The signaling traffic between two SPs can be distributed over several signaling routes.

SCCP(Signaling connection control part) 1>What are different functional elements of common channel signaling system ? Ans:a)MTP TUP b)UP ISUP

c)SCCP 2>What are function of SCCP service ? Ans:Communication with following a)database b)HLR c)VLR d)Location updating 3>Define NSP(n/w service part) Ans:Combination of MTP & SCCP is called NSP. 4>What are different services supported by SCCP ? Ans: a)connection oriented(CO) b)Connection less(CL) 5>Explain CO Ans: a)Transfers many or long signaling messages between two nodes b)establish a logical connection 6>Explain CL Ans:a)transfers short messages b)routing information 7>Define BSSAP(Base station system application part) Ans: Protocol between MSC/VLR and BSC 8>Define MAP(Mobile application part) Ans:Communication between MSC/VLR , HLR & GMSC 9>Diagram of SCCP Ans: BSSAP INAP RANAP MA P TCA P

CL

ISUP

CO SCCP MTP

10>Explain SCCP addressing for SCCP routing Ans: SCCP Calling address

called address GT(global title)

SSN(SCCP subsystem

Number) AI (address information) NA (nature of address) 3—national 4—international

NP (numbering plan) 1-ISDN/telephony numbering plan Ex:MSISDN , GT address 7-ISDN /mobile numbering plan Ex:IMSI , MGT(Location updating)

TT (Translation type)

TT:It directs the message to the appropriate GT translation. 0-ITU-T signaling 9-ANSI signaling 11>Define SSN Ans:The terminating nodes examines the SSN to identify the concerned over(node) HLR----------6 VLR----------7 MSC----------8 EIR-----------9 AUC---------10 SC------------12 BSC----------254 ISUP-----------3 12>Explain analogy between calls & C7 messages(MTP , SCCP) Ans: a)call A No RC Route Devices ETC B No

Terminating

b)C7 messages

1.MTP: Own SP SP

Dest

LS

Terminating

SLC

ST

2.SCCP

Calling add

GT

GTRC

DPC

To MTP

Called add Terminating 12>Command for SCCP calling addtress Ans:C7NPI:SP=2-9880; C7NSI:SP=2-9880,SSN=6&7&8; 13>Command for calling address of MSC/VLR Ans:MGCAC:INT= , NAT= ; 14>command for calling address of HLR Ans:HGCAC:INT= ,NAT= ; 15>When SSN is set to be allowed ? Ans:When signaling traffic is permitted in a subsystem via SCCP. 17>Explain example of GT translation Ans: A A BSC HLR

MSC A

6050

GTRC=1

MSC B 6113

GMSC

BSC SSN=254

GTRC=2

HLR

BSC B

HLR B

a. GMSC receives call for HLR B b. GMSC requests routing information from HLR B, sending an MAP messages via SCCP & MTP n/w c.The first digit of MSISDN(Np=1,NA=4) are used as called address. d.GMSC must transfer the message Result of translation is GTRC. 18>Command for GT routing Ans: C7GCI:GTRC=1,PSP=2-6113,PTERM,SSP=2-6050,SINTER; C7GCI:GTRC=2,PSP=2-6050,PTERM,SSP=2-6113,SINTER; 19>Define GTRC Ans:The GT routing case is a routing specification used to route SCCP Messages

PSP---Primary SP SSP---Secondary SP 20>Types of signal units Ans: 3 types MSU LSSU(link status signal units)-information for operating of SL FISU(Fill in signal units)-maintain acknowledgement cycle

OTHER QUESTION 1>Define ASR? Ans:ASR is answer to seizure ratio. ASR=Number of B Number answered/Total no. of calls attempt. 2>What action to be taken when ASR is low in a particular route? Ans:When maximum number of calls are failed after seizing channels then ASR is low. For outgoing ASR after minimum digit is sent to other operator channel generally seized.So it is required to fix length of digit to be 11.Because after subscriber dialing 11 digit channel should seize.Also for prepaid subscriber of called party ASR is low.Also if we have defined wrong codes for destination ASR also low.It can be traced in ISUP trace. For incoming ASR we can talk to other operator. 3>what is erlang. Ans: An Erlang is a unit of traffic measurement. In practice, it is used to represent one hour of traffic, although strictly speaking, Erlangs are dimensionless 4>Define Busy Hour Traffic (B.H.T.) Ans:Busy Hour Traffic (in Erlangs) is the number of hours of call traffic there are during the busiest hour of operation of a telephone system. This figure represents the quantity of traffic expressed in a unit called Erlangs. For the purposes of these calculations, 1 Erlang can be considered equivalent to 1 hour of calls.

5>what is 1 Erlang? Ans:If one CKT is busy for one hour. 6>Erlang calculation For example, if you know from your call logger that 350 calls are made on a trunk group, and the average call duration is 180 seconds, then the busy hour traffic will be: BHT = Average call duration (s) * Calls per hour / 3600 BHT = 180 * 350 / 3600 BHT = 17.5 Erlangs

6> Blocking Blocking is the failure of calls due to an insufficient number of lines being available. E.g. 0.02 mean 2 calls blocked per 100 calls attempted.

The blocking figure describes the calls which cannot be completed because insufficient lines have been provided. A figure of 0.01 means that 1% of calls would be blocked; this is a normal figure to use in traffic engineering. For some applications, 0.03 (3%) blocking is used.

Generally we are using GOS(grade of service ) as 2%.It is blocking value. 7.define lines Lines is the number of lines in a trunk group 8.What will do if utilization in a route is high? Ans: We have to increase E1s 9.what will do if congestion occur in a route? Ans:Increase E1s.

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