Wireless & Mobile Communications Multiple Choice Questions on “Signalling System No. 7 (SS7)”.
1. Which of the following is not a service offered by SS7?
a) Touchstar
b) 800 services
c) Alternate billing services
d) 400 services
Answer: d
Clarification: There are three main types of services offered by the SS7 network. They are the Touchstar, 800 services, and alternate billing services.
2. Which of the following service is called CLASS?
a) Touchstar
b) 800 services
c) Alternate billing services
d) 400 services
Answer: a
Clarification: Touchstar is also known as CLASS. It is a group of switch controlled services that provide its users with certain call management capabilities.
3. Which of the following service of SS& provides call return, call forwarding?
a) Touchstar
b) 800 services
c) Alternate billing services
d) 400 services
Answer: a
Clarification: Touchstar is one of the three main type of services offered by SS7. It provides services such as call return, call forwarding, repeat dialling, call block, call tracing and caller ID.
4. Alternating billing service uses CCS network.
a) True
b) False
Answer: a
Clarification: Alternate billing service and line information database use the CCS network to enable the calling party to bill a call to a personal number (third party number, calling card, or collect etc.) from any number.
5. SS7 was first developed by _______
a) ITU
b) Ericsson
c) CCITT
d) Motorola
Answer: c
Clarification: SS7 is an outgrowth of the out of band signalling first developed by the CCITT under common channel signalling standard, CCS no. 6.
6. Which of the layer of OSI is associated with NSP of SS7?
a) All layers
b) Upper three
c) Lowest three
d) Middle two
Answer: c
Clarification: The lowest three layers of the OSI model are handled in SS7 by the network service part (NSP) of the protocol. NSP is made up of three message transfer parts (MTPs) and the signalling connection control part (SCCP) of the SS7 protocol.
7. The function of _______ is to transfer and deliver signalling network.
a) MTP
b) CCS
c) ARDIS
d) CDPD
Answer: a
Clarification: The function of the MTP is to ensure that signalling traffic can be transferred and delivered reliably between the end users and the network. MTP is provided at three levels.
8. Signalling data functions are provided by __________
a) MTP level 1
b) MTP level 2
c) MTP level 3
d) TCAP
Answer: a
Clarification: Signalling data link functions (MTP level 1) provide an interface to the actual physical channel over which communication takes place. Physical channels may include copper wire, twisted pair, fibre, mobile radio and are transparent to the higher layers.
9. Signalling data functions are provided by __________
a) MTP level 1
b) MTP level 2
c) MTP level 3
d) TCAP
Answer: b
Clarification: Signalling data link functions are provided by MTP level 2. They correspond to the second layer in the OSI reference model and provide a reliable link for the transfer of traffic between two directly connected signalling points.
10. _________ provide procedures that transfer messages between signalling nodes.
a) MTP level 1
b) MTP level 2
c) MTP level 3
d) TCAP
Answer: c
Clarification: Signalling network functions (MTP level 3) provide procedures that ransfer messages between signalling nodes. As in ISDN, there are two types of MTP level 3 functions: signalling message handling and signalling network management.
11. Which of the following does not include in SS7 user part?
a) MTP
b) ISUP
c) TCAP
d) OMAP
Answer: a
Clarification: The SS7 user part includes the ISDN user part (ISUP), the transaction capabilities application part (TCAP) and operations maintenance and administration part (OMAP). The telephone user part (TUP) and the data user part (DUP) are included in the ISUP.
12. The TCAP part in SS7 refers to ________ layer of OSI.
a) Physical
b) Network
c) Data Link
d) Application
Answer: d
Clarification: The transaction capabilities application part in SS7 refers to the application layer which invokes the services of the SCCP and the MTP in a hierarchical format. TCAP is concerned with remote operations.
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