B Table Analysis Ericsson Switch

KPMG – Revenue Assurance

Aircel Bihar Team

Definition & Objective :-

B number Table :- Whenever a call initiated by a user, the call is handled and routed on basis of some predefined rules and parameters configured in Switch. These parameters also play a important role in CDR generation and interrogating other relative systems for appropriate charging.All such parameters and rules are configured under a specific table named B Number table. B number table is database of all codes required to connect the call to desired destinations.

Sample format of B Number table for Ericsson switch.

B Table Parameters

Table number

Number Format

Routing Table

Charging/ CDR Generation Parameter

Length Parameter

Calling Code

Forward & next digit analysis parameter

Destination type Parameter

Table number & Calling level :-

Below colored number indicates table number along with level code. If level code is defined with 4 digits then by default, B table will be formatted in below manner up to 4 levels (from shortest to longest digits).

In such a scenario, all the respective parameters such as CC/ RC/ F/ N etc will be associated only with main level code and not with all levels defined.

<30>-<0> <Table number> – <1st Digit><30>-<01> <Table number> – <2nd Digit><30>-<011> <Table number> – <3rd Digit> <30>-<0111> <Table number> – <4th Digit > ( Main Level)

Charging Parameter :- “CC”

CC :- CC is Charging case which indicates about the Charging & CDR generation of the routed calls for respective calling code in the switch. After analysis the charging case specifies how the call is to be charged

CC has normally 4 attributes :-

1. CC=0 - Post paid type CDR generation for the defined level.2. CC=75 - For Prepaid type CDR generation3. CC=2 - Having this attribute shows that no CDR will generate for respective calling code.

CC Parameter in switch decoded CDR

We can check the CC value in switch decoded CDR and understand the difference of Prepaid / Postpaid CC type for better analysis.

Postpaid CDR ( CC=0) Prepaid CDR ( CC=75)

Length Parameter :- “L”

L :- This column indicates the number length of the B-number. If the length is unknown, the minimum and the maximum number lengths are specified (min-max, e.g. 6-11).

In below example with ‘0111’ level the length is defined “L=6-11” with BNT=4 ( National number format). It means that with level ‘0111’ the B number can have min 6 digits & max 11 digits including level.

Number Format :- “BNT”

BNT= For proper formatting of called number and type definition BNT parameter is used.

BNT attributes :-

1. BNT=1 International Format2. BNT=2 Unknown Format ( Used for Short codes)3. BNT=3 Subscriber Number 4. BNT=4 National Format

In below example BNT=4 is defined for level ‘0111’ with “L=6-11” which signifies B number would be in National Number format where length size will be in 6 – 11 digits.

Modification Parameter :-”M”

M :- This parameter specifies how the modification of a stored B-Number is to take place. This parameter associated with BNT parameters for formatting the calling number.

Format : a[-b] where: a - Number of digits to remove b - Digits to add

The number of digits to be removed and the digits that are to be added in the digit magazine, in both cases counted from the first position of the number, are specified here. Removal takes place before adding, if both removal and adding have been requested. Modification shifts other digits in the number. Removal can be performed on received digits only. Removal of 0 digits (a=0) can be specified only if digits are added with the same command (b<>0).

In below example M = 1-0 indicates removal of first digit then added 0 so in this case prefix 0 will be trimmed first then 0 will be add and number will convert in national format as per BNT=4 defined parameter.

Below example explain how M parameters changing the complete number from dialed 100 to destination number 06156224609. M= 3 :- Indicates trimming 3 digit from dialed 100 number.

“-06156224608” :- To add given number after trimming 3 digit ( all digit of dialed 100 number are removed and 06156224609 is considered to be new dialed code)

Example of Modification

Routing Table :- “RC”

RC :- Routing Case defines the route table from which call will be routed. In RC table priorities are defined for the various networks / operators for final routing. By looking in referring table we can check the priorities defined as per marketing agreements .

Below example shows that a call to code beginning with 0112 needs to be routed using RC=243 table which further explains that routing will be through TG-BMN7GGO belonging to ‘GURGAON SWITCH (ACL NLD) having first priority P01=1 for NLD calls.

Destination Type :- “D”

D= Destination Type parameter defines the proper type of called number and segregate in multiple section for reporting purpose. This parameter should be in sync with BNT parameter.

Below example shows sync between D=6-0 ( International) and BNT=1 ( International Format)

D Parameter has below attributes :-.1.D=1-0 OWN B-SUBSCRIBER 2.D=2-0 USED FOR MOIP 3.D=3-0 STD MOBILE4.D=3-1 LOCAL MOBILE5.D=4-0 STD PSTN6.D=4-1 PSTN LOCAL/INTRA CIRCLE7.D=5-0 OTHER MSC SAME PLMN8.D=6-0 INTERNATIONAL CALL!   9.D=9-0 IVR/CRBT (SPECIAL NUMBERS)

Forward Parameter:- “F”

F :- For optimum utilization of B table configuration , F parameter is used to forward a calling level through another table in switch where same level is already defined.

Below example shows forwarding of calling level 101 through another table 31 where level is already defined with all respective parameters i.e. RC/CC/BNT etc.

Next digit analysis parameter :- “N”

N:- Next digit analysis

This parameter used to identify exact destination number, specially for non operator series numbers. Ex 1800. Toll free numbers starts from 1800 but not associated with any operator. For proper call routing system has to do next digit analysis after 1800This parameter will associate with respective table number where next analysis will take place.. In below example for 1800 calling N is referring 131 table where next digits ( excluding 1800) will be checked. If next digit is 101 then call will route through RC =405 and if next digit 102 then from RC =205.

ISKP parameter:-ISKP :- This parameter was used to forward Prepaid numbers call to IN interrogation when CAP 1 & CAP 2 technique were used. Now with CAP3 introduction, this parameter is not applicable.

This is important parameter to be check for prepaid numbers B table if still any circle is using CS+1 technique for call routing. Also has to check RC which is defined for IN routing.

In below example calling levels of 24 Table is routing through 135 which linked to IN.

Revenue Assurance Checks

Following parameters needs to be checked and validated from Revenue Assurance Perspective.

Charging Case (CC) association :- Correct D-Parameter association. Correct Routing Case (RC) association. Missing Codes in B-table. Internal Service Key (ISK) association for prepaid.

RA Checks & exceptionsB number

ParameterValidation to be performed Expected results Possible exceptions Working sheet

attached

B Table , Toll free, Customer care & Short codes number list

RA team needs to request switch team/networks for the complete and approved master list of all numbers that need to be defined across all MSCs (Local, STD, ISD, Toll free , VAS codes etc)

All codes should be defined in B table with proper levels

• Extra calling codes defined

• Few codes missing• Codes with wrong

levels defined• Inconsistency in

defining codes across switches

Circle wise Toll free numbers/ Short codes and special numbers from CSD team

To check for CC parameter authenticity

Non toll free codes can have CC=2 parameter (leading to Non generation of CDRs)

Retrieve complete B number level defined in MSCs and compare the same with codes in IN/Billing based on shortest digit or longest prefix

Exact Match of levels defined in MSCs, In and Billing system leading to accurate charging

• Missing codes in IN / Billing

• Extra Code defined in B table

CC parameter check All defined levels of B table must have correct CC parameter with RC number

CC or RC mismatch • Wrong CC define• RC number not

defined

D type validation Correct D type association with B level is important check in B table analysis

Wrong D type defined Wrong charging in Billing system incase D parameter value is used for charging of CDRs

RC & priority check Every code is associated with RC table and correct routing priority is configured as per marketing agreement.

Wrong priority defined Wrong priority can leads to revenue loss.

Microsoft Office Excel 97-2003 Worksheet

Microsoft Office Excel 97-2003 Worksheet

Microsoft Office Excel 97-2003 Worksheet

Microsoft Office Excel 97-2003 Worksheet

Thank you

Prepared by: Meghraj Gurjar (KPMG)