3. Origination and Termination Processes
Scheme
Call origination process
Transit
Operators
Voice Traffic Termination
Operator B
Subscriber B
Subscriber A
Operator A
Call termination process
The call termination process is totally different from the call origination process
4. Main types of operators
National operators
Land-line operators
Licensed Mobile Operators (CDMA, GSM)
Large Transit (VoIP) Operators
GSM Terminators
Small Transit (VoIP) Operators
VoIP: subscribers are connected via soft-phones or calling cards
Types of inter-operator connections (physical level): copper, optics, Ethernet
5. Transit operators
Key occurrence reasons
Technological
We couldn't
call to
another
continent
using only
a cable
Political
Different
countries,
each of
them have
it's own
policy
Commercial
The
government
prohibit
operators to
connect
directly
Personal
wealth
Management
companies
need to earn
profit
6. Tarification
Main principles
Long distance tarification
International tarification
Dial code
Description
Price
Valid Date
Tarification
38
Ukraine
0.15 USD
1.1.2000
1/1
38 067
38 097
38 096
Ukraine
Kyivstar
0.10 USD
1.1.2001
1/1
38 050
Ukraine MTS
0.08 USD
1.1.2005
1/1
0/1/1 – per second
0/60/60 – per minute
tarification
tarification
60/60 tarification principle uses only in Mexico
7. Routing
Example
This is a process of choosing the route for the voice call
The process is based on tariff differences
and quality of the route
Subscriber A
Operator A
Transit Operators
Operator B
Subscriber B
8. Voice over Internet Protocol
History
VoIP technology occurred in the early 2000. It was a
behavior of the telecommunications industry and the
openness and freedom of the Internet that brought
this technology to the forefront of communications.
And, it will be the economic forces that provide the
motivation for companies to develop and use VoIP
technology.
By 2000, VoIP calls accounted for 3% and by 2003 that number had jumped up to 25%
9. Income distribution
Among the telecom operators
Cost
0.50 $/min
0.10 $/min
0.25 $/min
0.20 $/min
0.17 $/min
0.15 $/min
Operator
A
Operator
B
Margin
0.05$/min
Subscriber
A
Margin:
0.25$/min
0.00
$/min
Margin
0.03$/min
Margin
0.02$/min
Transit Operators
Margin
0.05$/min
Margin:
0.10$/min
Subscriber
B
Transit operators do not have their own subscriber base
11. Quality of the routes
Main definitions
Premium
quality
TDM
quality
Retail
quality
The route
with absolute
quality:
DTMF, CLI,
FAX,
reasonable
PDD
The route
shows high
quality:
It is “pig in a
poke”.
Good ASR,
ACD, PDD.
CLI might
be hidden
All indicators
should be
checked twice;
CLI, FAX, DTMF
optionally
Direct
quality
GSM
quality
Wholesale
quality
Obviously it is
a route from
the direct
supplier
Route
provided
through
GSMgateways
Low-quality
routes. No CLI,
DTMF, FAX
options. FAS
could be
expected
FAS – False Answer Supervision
13. FAS
False Answer Supervision
False Answer/False Ring
Early Answer
Late Disconnect
False answers occur when a carrier deliberately charges a connection period while in reality the call was
not connected to the destination.
17. GSM Network Architecture
Scheme
Base Station
Base Station Controller
The “intelligent” part of the
base station subsystem.
Performs radio channels
management
Cell – is the smallest radio coverage area in the network
LA – Location Area (a group of cells)
18. GSM Network Architecture
Scheme
HLR – Home Location Register
AuC – Authentication Center
VLR - Visitor Location Register
EIR – Equipment Identity Register
MSC – Mobile Switching Center
19. GSM Carrier Frequencies
GSM networks use various bandings, or in other words different Wave streghts/lenghts/frequecies to provide their services
GSM 900, is where the
specific mobile carrier
uses, 900Mhz as the
wave length, or banding
for its services. This
is one of the lowest
of todays commercial
communication services
GSM 1800 networks use
a wide range of signals,
starting from 800 MHz
and then 1700 MHz or
else 1800 MHz at a
maximum
GSM 900/1800 network - it is a
single network with a common
structure, logic, and monitoring
where the phone is not switching
GSM-900 and GSM-1800 are used in most parts of the world: Europe, Middle East, Africa, Australia and
most of Asia. In South Americas it is in Costa Rica (GSM-1800), Brazil (GSM-850, 900 and 1800),
Guatemala (GSM-850, GSM-900 and 1900), El Salvador (GSM-850, GSM-900 and 1900).
20. GSM Gateway
What is it?
A VoIP GSM Gateway
enables direct
routing between IP,
digital, analog
and GSM networks
Through least cost
routing the gateways
select the most
Cost-effective
telephone connection
With these devices
(fixed cellular terminals)
companies can significantly
reduce the money they
spend on telephony,
especially the money
they spend on
calls from IP to GSM
They check the
number which is
dialed as well as
rate information
which is stored in
an internal routing table
The core idea behind cost saving with VoIP GSM Gateways is Least
Cost Routing (LCR)
21. Gateway
Where does the Internet occur?
Subscriber
A
Subscriber
B
INTERNET
Operator B
Operator A
Copper
connection
Transit operator 1
Gateway
VoIP
Transit operator
Optical connection
Transit operator 2
TDM connection
IP connection
Transit operator 3
Transit operator 4
Ethernet
connection
Internet is most common to appear while call is transmitting between transit
operators
22. GSM Gateway
Where is it?
When using a gateway you can save money due to calls organizing between
subscribers without use of fixed-line operators
23. GSM Gateway
Examples of use
1. How do call centers use the gateway:
Internal
subscribers
PBX with
support of
SIP or H.323
Gateway
GSM
subscriber
2. How do companies use the gateway:
Internal
subscriber
PBX with
support of
SIP or H.323
VoIP gateway addresses a request to PBX that:
●
●
●
Dials GSM number of the subscriber through the gateway;
Calls the requested extension number;
If both sides answered, GW establish a voice connection.
GSM
subscriber
There are several types of network, connected with the gateway:
●
●
●
GSM and IP (VoIP) networks;
PSTN and VoIP networks;
PSTN and GSM networks;
24. GSM Gateway
Architecture
GSM Gateways are usually using by offices, call centers and gsm terminators.
Usually GSM Gateways are placed to the space with limited human access and in
different cells (ex: Data Centers, lofts, etc.)
25. GSM Gateway
Net Tariffs
Transit operators
Subscriber
A
0.40$/
min
0.20$/
min
Operator
A
Margin:
0.05$/min
Margin:
0.20$/min
0.05$/
min
Margin:
0.05$/min
0.10$/
min
Gateway
Margin:
0.05$/min
Operator
B
Margin:
0.05$/min
0.15$/
min
(with Sim-cards)
Margin:
0.10$/min
Net tariffs
0.00$/
min
0.00$/
min
Subscriber
B
Subscriber
B
When terminator diverts call to subscriber B and use only operator's B
network, he will have a net tariffs
27. Anti-Fraud
What's that?
If gateway acts not like a
human, it becomes a target
to the Anti-Fraud
Anti-Fraud – it is a software complex for detecting gateways, based on analyzing
subscriber's behavior.
28. Anti-Fraud would not block if:
Real Subscriber:
- Calls from different locations;
- Calls limited number of
subscribers (family);
- Uses 1 Sim Card;
- Send SMS
To fight Anti-Fraud you will need many gateways in a different cells
29. Anti-Fraud
Basic principles of work
Anti-Fraud can analyze:
Lots of outgoing calls
in a short period of time
to the different
numbers
Absence of incoming
traffic and no
operator's
services usage
Sim-card profile
analyzing
Auto-pro-ring
Anti-Fraud is dangerous for a whole SIM cards series, which was activated from one
place in a short time period
30. Anti-Fraud
IMSI
MCC - mobile country code
An IMSI is usually presented as a 15 digit long
number, but can be shorter.
MNC - mobile network code
MSIN - mobile subscription
identification number
IMSI - International Mobile Subscriber Identity
33. Sim-box
What's that?
It is one of the hardware modules of GSM termination equipment.
Functions:
1. To make a Sim-card not plugged into the gateway
2. Possibility to use a lot of Sim-cards
3. Possibility to register a Sim-card on a specific gateway via Internet
The main function of this element is to store the array of Sim-cards, which take part in IPtelephony.
34. Anti Anti-Fraud
What for do we need it:
We will need a lot of Sim-cards, which could move between the gateways, would make a
limited number of calls, receive incoming calls and use operator's services (SMS, Internet)
35. Anti Anti-Fraud
Processes
The key task of Anti AntiFraud system is to hide gateways and
imitate that Simcards are acting like a real subscribers.
Sim-Rotation
Sim-Migration
SIM cards within each sim-box can be
divided into groups, each
of these groups can assigned to a Separate
GSM-module of VoIP-gateway.
Over time, the system is able to make changes
within each group, changing sim-card
which is responsible
for making voice calls from one to another
CDR – Call Detail Record
If you have several GSM-gateways
located in different parts
of the city, system will make
SIM card to make calls from every
gateway by turn, creating an illusion of
subscriber movement, thus helping to protect
your cards from blocking by the
mobile operator
36. Anti Anti-Fraud
Anti-Spam
Anti-Spam
Analyzing calls, which are
going through the soft
switch
Identifying numbers, which
are making calls, to which numbers
they're calling and analyzing calls
frequency
Helps to include numbers to
black, white or gray lists
38. ANTRAX Solution
HW and SW Solution for business
Our ANTRAX Solution consist of:
1. Sub Rack 2. Sim board
3. GSM board 4. Sim Server 5. GUI
39. ANTRAX Solution
Specification
It is a hardware module of Antrax system with 15
universal slots.
It acts as a switch on the Ethernet level for GSM
and/or Sim -modules
This hardware component consist of two GSM modules
(we have 2 active channels)
This HW component may contain up to 20 Sim-cards
It is a set of tools (scripts and algorithms) which forms
the basis of Anti Anti-Fraud system
Graphical User Interface. Which gives you an ability to
control your sims in one click
