The service switching point (SSP) is the telephone exchange that initially responds when a caller dials a number by querying a service control point (SCP) database to route the call. The SSP uses SS7 protocols to set up, manage, and terminate calls with other SSPs. The SSP implements a basic call state machine to represent the call states from start to finish and queries the SCP at detection points to determine how to proceed with the call.

1. SERVICE SWITCHING POINT
In telephony, a service switching point (SSP) is the telephone exchange that initially
responds, when a telephone caller dials a number, by sending a query to a central database
called a service control point (SCP) so that the call can be handled. The service switching
point uses the Signaling System No.7 (SS7) protocols which are responsible for the call
setup, management, and termination with other service switching points.

2. • Service Switching Function (SSF) or Service Switching Point (SSP) is co-
located with the telephone exchange, and acts as the trigger point for
further services to be invoked during a call. The SSP implements the
Basic Call State Machine (BCSM) which is a Finite state machine that
represents an abstract view of a call from beginning to end (off hook,
dialing, answer, no answer, busy, hang up, etc.). As each state is traversed,
the exchange encounters Detection Points (DPs) at which the SSP may
invoke a query to the SCP to wait for further instructions on how to
proceed. This query is usually called a trigger.

3. MSAG
• A 'Multi-Service access node' or (MSAN) also known as MSAG or 'Multi-
Service Access Gateway' is a device typically installed in a telephone
exchange (although sometimes in a roadside serving area interface cabinet)
which connects customers' telephone lines to the core network, to provide
telephone, ISDN, and broadband such as DSL all from a single platform.
Typical outdoor MSAN cabinet consists of NarrowBand (POTS),
BroadBand (xDSL) services, batteries with rectifiers, optical transmission
unit and copper distribution frame. Referenced:

4. • MSAG is capable of connecting the analog interface subscribers directly to
the IP network, and performing voice/fax conversion between the subscriber
side and the IP network side. By accessing the ordinary users at the POTS
interfaces and BRI interfaces, MSAG can access the narrowband voice
services. Under the control of the Soft Switch, it implements voice
compressing/decompressing (G723.1, G711, G729), facsimile (T.30, and
T.38), VOIP and IP FAX services under H.248/MGCP protocol. At network
side, it provides 100M Base-TX/FX Ethernet interfaces to IP bearer
network.

5. • In the NGN with the Soft Switch, MSAG primarily fulfills end office
functions, and works together with the signaling gateway to implement
the telephone subscriber access. When MSAG is the caller in a
conversation, it works with the Soft Switch to implement the call
origination, subscriber dialup DTMF and tone playing. When MSAG
is the called in a VoIP call, it works with the Soft Switch to implement
the call termination and subscriber ringing.

6. • In addition, MSAG provides broadband access functions, supports access of
ADSL users, and can be expanded to provide VDSL modes. Just by making
use of the existing ordinary telephone copper twisted pair, the ADSL
broadband access provides sufficient bi-directional broadband capacity. It
supports both narrowband voice services and broadband data services such
as VOD, videoconference, online browsing and e-commerce, thus
substantially improving the utilization of traditional networks.

7. IP SWITCHING
• Ip switch has two switching factions.
Switch 1 consists
 fast Ethernet(FE 100mbps): - use for our campus
Gigabite Ethernet (GE 1Gbps) this switch is user interface: - use for MSAG
Controller part/interface: - control the switching interface
Switch 2 also consists
fast Ethernet(FE 100mbps)
Gigabite Ethernet (GE 1Gbps) this switch is user interface
Controller part/interface

8. FIBER
DWDM
ODF
OTN
SSR2
T64-1
MSA
G
TCU
TN
MDF
DUG
SSR1
T64-2
To
OTHER
SITE
TX
DEVICE
CUSTOMER
 DATA
 I/NET
 PSTN
To
OTHER
SIT BY
MW
DUW
To
3G
To
2G
TO
OTHER
SITE
Optical
distribution
frame
NB: - SSR - smart service package
SP - smart package

9. SP
FROM
TUC
TO
OTHER
SITE
TO
OTHE
SITE
BBU

10. • IP address of Gambella SP420
10.0.11.152 /244169 Michael safer
10.0.11.153 /244186 Dombosco
10.0.11.154 /244179 Microwave
10.0.11.174 /244193 bonga
10.0.11.169 /244180 SSR1 main branch
10.0.11.170 /244180 SSR2 main branch

11. Past is your experience
Present is your experiment
Future is your expectation
 There for Use your experience in your experiment
to achieve your expectation…………