VOIP

what is the signaling that was developed by the International Telecommunication Union Telecommunication Standardization Sector (ITU-T)

is used to perform out-of-band signaling in the Public Switched Telephone Network (PSTN).

Enhances the PSTN by handling call establishment, exchange of information, routing, operations, billing, and support for Intelligent Network (IN) services.
also call control

switch information messages to set up, manage, and release telephone calls as well as to maintain the signaling network.

what type of signaling network is SS7

SSP
SCP
STP
F
C

what is the SS7 network architecture built for

also are referred to as signaling points, endpoints, exchanges, switches, or nodes
separate the voice network from the signaling network

acts as a routing address in SS7.

Each signaling message contains the

Service Switching Point (SSP)
Signal Transfer Point (STP)
Service Control Point (SCP)

are end office or tandem switches that connect voice circuits and perform the necessary signaling functions to originate and terminate calls.

routes all the signaling messages in the SS7 network.(route traffic in clooud)

provides access to databases for additional routing information used in call processing. ( who the call goes to
The key element for delivering IN applications on the telephony network.

End office SSPs originate and terminate calls, and core network switches (STPs) provide tandem or transit calls.
provides circuit-based signaling messages to other SSPs for the purposes of connecting, disconnecting, and managing voice calls

protocols used are ISDN Primary Rate Interface (PRI) or channel associated switching (CAS).

end office is in charge of translating subscriber protocol requests into SS7 messages to establish calls.

uses dialed number to complete the call unless its an 800 or 900 number then it sent to

route or switch all the signaling messages in the network based on the routing information and destination point code address contained in the message.

logical connectivity between SSPs without requiring direct SSP-to-SSP links

STPs are configured in pairs and are mated to provide
"considered the home STPs for the directly connected SSP or SCP."

is capable of performing global title translation.

network's job to properly route circuit-based SSP packets to the destination.

network's job to properly route non-circuit based message packets between the SSP and the database interface known as the SCP

also measure traffic and usage. Traffic measurements provide statistics such as network events and message types,

is used to centralize the SCP and database selection versus distributing all possible destination selections to hundreds or thousands of distributed switches.

If the SSP is unaware of the destination SCP address, it can send the database query to itslocal

STP looks at the global dialed digits and through its own translation table to resolve the following

defines network interconnection and separates capabilities into specific areas of functionality

Where can the STP implementation occure

The local, regional, and national STPs transfer standards-based SS7 messages within

International STPs provide international connectivity where the same

what can gateway STP provide

can be deployed and installed on separate dedicated devices or incorporate them with other SSP
functions onto a single end office or tandem switch

CCS7 is the ITU-T version of

provides the interface to the database where additional routing information is stored for non-circuit based messages.

provide the interface to the system's database.

The interface between the SCP and the database system is accomplished by a standard protocol, which is typically

Provides the routing information for special numbers, such as 800, 877, 888, 900, and 976 numbers.

Provides subscriber or user information such as screening and barring, calling-card services including card validation and personal identification number (PIN)
authentication, and billing.

Provides the 10-digit Location Routing Number (LRN) of the switch that serves the dialed-party number

used to route the call through the network, and the dialed-party number is used to complete the call at the terminating SSP.

Used in cellular networks to store information such as current cellular phone location, billing, and cellular subscriber information

Used in cellular networks to store information on subscribers roaming outside the home network

All signaling points in the SS7 network are connected by

The signaling links are typically 56- and 64 kbps data network facilities, either on standalone lines or extracted on channelized facilities such as structured

is the simplest form of signaling, in that the signaling and voice paths are directly connected between the two signaling endpoints.
signal and voice floows the same path

uses a separate logical path for signaling and voice
The signaling messages travel through multiple endpoints before reaching the final destination
most common for SS7 network

uses a separate logical path for signaling through the minimal number of transfer points to reach the final
destination
network delay is minimized
more expensive

A link
b link
c link
d link
e link
f link

Signaling links are grouped together into WHAT when the links are connected to the same endpoint

provide load sharing across all the links in a linkset.

occurs when signaling endpoints re-address the messages to adjacent point codes.

have statically predefined routes for destination endpoints.
The route is made up of linksets; linksets can be part of more than one route

routing tables to provide alternate routes when the current route is unavailable.

availability of signaling in the SS7 network is critical to connect and serve telephone network users.

provide the necessary load sharing and redundancy required to maintain SS7 network reliability.

how may layers does the SS7 protocal stack have

L1, L2, and L3 provide the transport protocols for all other SS7 protocols
includes network interface specifications, reliable transfer of information, and message handling and routing

provides end-to-end addressing and routing for L4 protocols such as transaction capabilities application part (TCAP).

primarily is a link-by-link signaling system used to connect telephone or speech calls as well as facsimile calls.

is a circuit-based protocol used to establish and maintain connections for voice and data calls

provides access to remote databases for routing information and enables features in remote network entities

the physical and electrical characteristics of the signaling link.

protocol is used to create reliable point-to-point links between endpoints in a network.
uses packets called signal units to transmit SS7 messages

protocol routes SS7 messages and relies on the delivery of messages from MTP2.
also uses primitives to communicate to L4 protocols such as SCCP, ISUP, TUP, and TCAP

routes SS7 messages during normal conditions
identifies whether the destination address is the receiving endpoint or whether the message needs to be routed

Determines the SS7 message's destination endpoint address.

Identifies the user and delivers the user information (SCCP, TUP, ISUP, TCAP, or network management) in the SS7 message to the upper-level protocol.
User part function is not provisioned.
User part function is out of service.

Interfaces with MTP2 to route messages over the network.

personnel statically maintain signaling endpoint routing tables

function reroutes traffic in the SS7 network.
handles the rerouting of traffic through alternate links or linksets during network link failures.
controls
the flow of traffic to specific endpoints during network link failures.

Monitors and controls the individual links of the signaling endpoint.

Exchanges routing information and status between signaling endpoints.

Routing problems are transmitted using

Used to reroute or divert traffic and control congestion during network failure conditions

MTP2 monitors the level of messages queued in buffers (both output and retransmission) and alerts SNM in case of congestion.

provides networkservices on top of MTP3
CAP typically uses WHAT? services to access databases in the SS7 network.
services enable the STP to perform Global Title Translation (GTT)

the combination of SCCP and MTP3 is called

SCCP supports services for TCAP and ISUP

SCCP provides the transport layer for the connectionless services of TCAP
Together, SCCP and MTP3 transfer non-circuit based messages used in these services

maintain the transfer of SCCP messages during failure conditions, including network and subsystem failures.

was the first SS7 user part defined when all calls were considered voice calls
supports physical circuit connections but is unable to handle the virtual connections and bearer circuits

connects, manages, and disconnects all voice and data calls in the PSTN.
sets up and tears down the circuits
subscribers include ISDN, analog, and ISDN-to-analog users.

provides thetransaction capabilities carried out by non-circuit based messages used to access remote databases and invoke remote feature capabilities in network elements
first used for 800-number translation.

The Intelligent Network (IN) also uses WHAT? to invoke features in remote end offices

The database information is used for 800, 888, and 900 service,

uses SCCP and MTP to route transaction messages in the SS7 network
messages to communicate from one signaling point (Exchange X) to another signaling point (Exchange Y).