abnormal sd drop kpi value

8/9/2019 Abnormal SD Drop KPI Value

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NA05602603 / Abnormal SD Drop KPIValue

Problem Description:

While monitoring the Network, NPO has observed that Counter 1003

(TRN!CT"ON! #"$ %&' TO R%"O #"$ is re)orting higher than *ounter 0+0-1

(!%CC. !!"/N or *ou)le o hours or 1 T!2 !in*e *ustomer is using both

*ounters in one P" (!% %ro) so *ustomer is a*ing une4)e*ted high and abnormal(be5ond 100 6 !% dro)s2

Customer is *laiming that *01003 (TRN!CT"ON! #"$ %&' TO R%"O #"$ should

get in*remented wrt number o assigned !% whi*h are in *0+0-1 (!%CC. !!"/N

means value o *01003 should be 78 *0+0-1 as )er their ormula and logi*2

.ere are ollowing observations and *om)arison o two *ounters (b5 T! Team2

an*han !harma T! T! Team



%ue this malun*tioning (as *ustomer is *laiming o *ounter P"s are degrading

abnormall5 and dro) rate is in*reasing be5ond 100 62

TS Analsis:

#irstl5 T! has made *lear that both *ounters are not the )art o same P" as

*om)are to N!N standard P" 2

Customer is using their own ormula or maintenan*e so here are the details as

ollow

!ustomer "ormula 9

SD Drop rate# 100 :%'CO%'(servi*e2!%CC.;!!"/N, 0, 0,

(tra<*2!%CC.;R%"O;#"$ = tra<*2!%CC.;R#;O$%;.O = tra<*2!%CC.;&!'R;CT

= tra<*2!%CC.;C!&;R'!'T = tra<*2!%CC.;N'TW;CT =

tra<*2!%CC.;"!;#"$;O$% = tra<*2!%CC.;T!;#"$=

tra<*2!%CC.;$P%;#"$>servi*e2!%CC.;!!"/N2




.ere ser$ice%SD!!&'ASSI(N is servi*e level ?easurement *ounter c05)02* and

tra+c%SD!!&',ADI-'"AI. is tra<* level ?easurement *ounter c0*0032

s s we have seen so ar or tra<* level P"s N!N standard P"s are not using an5

servi*e level *ounter2

N!N !tandard #ormula9

SD Drop rate#

sum(sd**h;radio;ail=sd**h;r;old;ho=sd**h;user;a*t=sd**h;b*su;reset=

sd**h;netw;a*t=sd**h;abis;ail;*all=sd**h;abis;ail;old=sd**h;bts;ail=

sd**h;la)d;ail=sd**h;a;i;ail;*all=sd**h;a;i;ail;old

100 : @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 6

sum(sd**h;assign=sd**h;ho;seiA

.ere Scc assi1n is tra<* level *ounter *0100 (des*ribed in trailing mail

.ere we are usimg *0100 not *+0-1 or !% !!"/N2

!in*e P"s are based on basis o *al*ulations o diBerent *ounters so we have

investigated this issue in detail and here is anal5sis rom investigation2




There are two diBerent level o *ounters as ollow where we will *om)are *0+0-1with *01003 in detail2




!0*003 is Number o !%CC. transa*tions ended be*ause o a radio ailure2

Impact9 Call *leared Reason or the "m)a*t9 '4ternal > bis "ntera*e




!05)02* is Number o !%CC. ssignments whi*h will get u)dated ater st'In

message will be re*eived on aabis2




!o rom the *all ow or signaling *hart o *all )hase 1@D we *an see when both

*ounter will u)date2

s )er N'% we *an read that *ounter c05)02* SD!!& ASSI(N4 will get

in*remented onl5 when 'stablish "ndi*ation message will be re*eived on bis2 .ere

c05)02* SD!!& ASSI(N4 *ounter is signi5ing that ?! has also moved to !%CC.

Channel not E!C has assign the !%CC. to ?!F (as *ustomer is inter)reting2

!o there is diBeren*e between two des*ri)tions wrt *ounter value2 s name signiGes

that !%CC. !!"/N so one *ould think that *ounter will get in*rement Hust ater

"mmediate ssignment *ommand sin*e in this message !C assign the !% to ?!2

ut here is not that *ase be*ause c05)02* SD!!& ASSI(N4 will get in*remented

ater st'In message will be re*eived in &$ rom ?!2

#or Counter c0*003 T,ANSA!TI-NS "AI. D T- ,ADI- "AI.4 des*ri)tion is

as Number o !%CC. transa*tions ended be*ause o a radio ailure2

Impact9 Call *leared ,eason or te Impact9 '4ternal > bis "ntera*e




?eans when an !%CC. transa*tion ends be*ause o a radio ailure and the RR?

releases the !%CC.2 This ma5 ha))en at an5 time in 1@D *all )hases2 !o !%

transa*tion *ould ends beore 'stablish "ndi*ation message, be*ause !%CC.

transa*tion will get start ater "mmediate ssignment messageor it ma5 get

u)dated ater 'stablish "ndi*ation message but during 1@D *all )hase2

!o the reason or in*rement beore 'stablish "ndi*ation *an be due to in*rease in

*010+ (reer des*ri)tion in trailing mail, where ?! ma5 get lost2 lso we *an reer

reason or *0100+ in*rement as ollow9

,easons tat tri11er te counter9

12 Phantom RC.s that have a valid establishment *ause2-2 The T! *an hear the ?!, but the ?! *annot hear the T!, and so the ?!

does not res)ond to the "??'%"T' !!"/N?'NT message with a !?2

32 ?! is a**essing the network at the limit o sensitivit5 and messages are lost2I2 Poor Radio *onditions2+2 ?! is a**essing network through another T! (*o@*hannel, *o@!"C

intereren*e2

So ue to increase in tis counter c0*0)5 7e ma see tat c0*003 7ill be

i1er tan c05)02*2 !o besides *om)aring *01003 with *0+0-1, *om)arison

should be done between *01003 and *0100 !%CC.;!!"/N (reer des*ri)tion in

trailing mail2 C0100 will be u)dated or e$er sin1le SD 7ic 7ill be

assi1ne to 8S in Immeiate Assi1nment *ommand2

.ere we *an also bring one servi*e level *ounter *0+0-0 (T3101 e4)ired in )i*ture

whi*h is relativel5 same as *ounter *010+2

!in*e *0+0-1 will be u)dated or )assed !% ssignment (or whi*h 'st "nd is

re*eived and *0+0-0 will be u)dated or ailed !% assignment (or whi*h T3101

e4)ired message is re*eived2

.ere we have des*ri)tion o all other *on*erned *ounters2




Analsis rom .o1s:

#rom the given ?easurement Gle or T! +-1 we *an see *learl5 ollowing related

*ounters9

!ounter Valu

e

Description brie4

* 0*00):S!!'SI9'"-,'

I88'ASSI(N

53

3

Total Number o SD ,e;uest

2 0*003 :

T,'"AI.'D'T-',ADI-'"AI.

*0

56

"aile ue to ,aio in *<= call

pase

3 0*0)5 :

T,'"AI.'SD!!&'A>IS'P

,'!A..

26

65

"aile ue to 8S lost or 8S stop

responin1

05)020 :

S'T3*0*'?PI,D

26

02

"aile ue to timer e@pire

5 05)02* : *2 stablis Inication messa1e




S'SD!!&'ASSI(N 6 recei$e

.ere data *a)tured in the ?' Gles *learl5 indi*ating that c0*00) would be alwa5shigher than all mentioned *ounters2 nd c0*00) should be *om)ared with rest

mentioned *ounters2

!o rom the des*ri)tion o all *on*erned *ounters we have veriGed that *01003

*annot be *om)ared with *+0-1 and to use this in one P" (as *ustomer has used

is also invalid2

In$ali:

SD Drop rate# 100 :%'CO%'(servi*e2!%CC.;!!"/N, 0, 0,

(tra<*2!%CC.;R%"O;#"$ = tra<*2!%CC.;R#;O$%;.O = tra<*2!%CC.;&!'R;CT= tra<*2!%CC.;C!&;R'!'T = tra<*2!%CC.;N'TW;CT =

tra<*2!%CC.;"!;#"$;O$% = tra<*2!%CC.;T!;#"$=

tra<*2!%CC.;$P%;#"$>servi*e2!%CC.;!!"/N2

!in*e in this ormula whole *al*ulation is divided b5 servi*e2!%CC.;!!"/N whi*h is

*0+0-1 and *0+0-1 ma5 be or ma5 not be greater than

tra<*2!%CC.;R%"O;#"$ (*01003 and other tra<* *ounters2 !o where *01003 will

be higher than *0+0-1 bnormal or Wrong !% dro) will be seen2

"n o))osite to that N!N !tandard P" tool is using *0100 whi*h would be alwa5s

higher than all

mentioned *ounters in the P" so *orre*t values will be re)orted2

sum(sd**h;radio;ail=sd**h;r;old;ho=sd**h;user;a*t=sd**h;b*su;reset=

sd**h;netw;a*t=sd**h;abis;ail;*all=sd**h;abis;ail;old=sd**h;bts;ail=

sd**h;la)d;ail=sd**h;a;i;ail;*all=sd**h;a;i;ail;old

100 : @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 6

sum(sd**h;assign=sd**h;ho;seiA

!onclusion:

#rom this nal5sis issue o bnormal P" and Counter ?alun*tioning gets ruled out2

Impact o tis ormula:




5 using this ormula !% %ro) P"s ma5 also mislead the investigations sin*e !%

%ro) and !% #ail are diBerent P"s2 "n this *ase due to !% ail, !% dro) P" will

deGnitel5 get aBe*ted2 Customer will )hase higher dro) rates than a*tual2 #or

T&N"!"N we have seen this )roblem2

>>R

an*han !harma


abnormal sd drop kpi value

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