S38.115/Spring
2005
Prof. Raimo Kantola:
This list of possible
questions can be used as a
reading guide
for the course. It does not necessarily contain all the questions that
may
appear in an exam.
1. Describe
briefly different types of networks and discuss the layering of
functionality
in networks.
2. Discuss differences between private and public telephone networks.
3. Compare the similarities and differences in networking architectures
and
functioning principles of PSTN/ISDN and IP for telephony. Discuss how
ISDN
network functionalities are transformed in
packet
telephony networks.
4. Generations of the Switching systems and
their life cycles.
5. Types of traffic in comparison to network hierarchy – define terms
such as
incoming traffic and all similar terms.
6. Fundamentally, why is signalling needed?
7. Give the
pricipal structure of a signaling
system as a state machine using both algebraic and graph representation
for the
state machine. Describe also the
signaling flow chart
method and
compare it to the state machine method as a description and
specification
method.
8. Classify PSTN signaling systems and
tell about
their development roadmap.
9. Describe analogue subscriber line signaling.
10. Explain principles of R2 signaling.
11. What are the limitations of line associated signaling?
How does CCS7 help to overcome those limitations?
12. Define the terms CCS7 network,
point code,
link, link set.
13. What are the reliability and
real-time
requirements for CCS7? Give some fundamental reasoning by any signaling should be highly reliable.
14. Describe the functional structure of CCS7.
15. Describe the functional structure of MTP.
16. Define the terms used in MTP: signaling
link,
link set, signaling route, signalling
route set.
17. Describe the message types in MTP and give the structure of the MTP
information message.
18. Give an example that animates the concept of network in MTP.
19. Describe the addressing in MTP and in SCCP. In the light of
addressing
explain when SCCP is needed.
20. Explain the Global title in SCCP:ssä.
Give an example of usage in a network.
21. The advantages and disadvantages of CCS7.
22. Describe the structure of basic access in ISDN and the reference
points
defined for the basic access.
21. Describe the basic access activation procedure in ISDN.
22. Describe the diffferent modes of DSS1 signaling.
23.
Describe the frame structure and the method of synchronization in the
S-interface.
24. Describe the architecture, the principles of DSS1 signaling
and the connection establishment procedure.
25.
Principle of voice coding in PSTN and ISDN. How is VOIP different in
this respect.
26. Outline
methods to measure the voice quality objectively and subjectively.
Consider the
impact of delay on voice quality.
27. Explain
the E-model.
28. Explain
the PCM hierarchy.
29. Discuss the requirements to signaling
that follow
from the needs of voice transfer and
in
particular from voice quality.
30.
Describe the mechanisms for call identification in ISUP.
31. Succesfull call
setup in
ISUP-signaling using a signalling flow
diagram.
Explain the semantics of key ISUP messages that appear in the flow.
32. How is the compatibility of consecutive ISUP versions managed in
order to
ease the deployment of new versions?
33. Describe the method of specification for interworking
of message based signaling systems.
34. What is
the purpose of TCAP, describe also its structure. Compare TCAP with OSI.
35. Describe TCAP operation types. Consider
usefulness
of the operation types from the point of view of an application that
uses TCAP.
Also discuss the overall added value of
TCAP to
applications.
36. Describe the principle of unstructured dialogue in TCAP.
37. Describe the structured dialogue in TCAP.
38.
Describe and compare general mobility management principles in circuit
switched
GSM and in GPRS.
39. Show
how a number analysis tree would grow under the assumption of free
numbering
and mobility of cellular network uses and when directory
numbers (e.g. MSISDN numbers) would
directly be
used for analysis. Give the argument why this architecture does not
scale.
40. MAP development phases, compatibility of MAP-versions.
41. Define
the concept of PDP context. Explain the PDP context establishment
procedures.
42. Addressing principles of MAP -messages in a GSM-network.
43. Describe the use of TCAP services
by MAP.
44. Location management principles and procedures in MAP for CS and PS
services.
45. Terminating call routing in GSM. Give also the variant with Number
Portability.
46. MSC-to-MSC handover in MAP.
47. Describe Security operations in MAP for CS and PS services.
48. Subscriber management operations in MAP (original GSM and GPRS)
49. Describe GSM-supplementary services operations in MAP.
50. USSD-service and its function.
51. GSM short message service from the point of view of MAP.
52. Routing and addressing of short messages over GSM.
53. The goals and phases of CAMEL specifications. Describe also the
phase 1
CAMEL-architecture.
54. Originating and terminating call prosedures
according to CAMEL.
55. Describe the tasks of the original GSM Core Network elements and
compare
them to the tasks of the GPRS core network elements.
56. Explain
the IN architecture.
57.
Describe the MAP support for CCBS.
58. Define
the factors of Quality of Service in IP Voice. What are the principal
means to
maintain and
improve the quality of IP Voice.
59.
Describe the functional structure of a voice gateway (equipment and
software
layers in sending and receiving voice).
60. Discuss
packet overhead in IP voice. What can be done to reduce the overhead?
Where is
that applicable?
61. Discuss the status of VOIP technology. What is still missing?
62.
Describe the RTP protocol. What are the main header fields and
functions?
63.
Describe the RTCP protocol. Show the information passed in the
protocol,
explain relation to RTP and the goals of RTCP.
64.
Describe the functions and use of RTP in IP Telephony.
65. Describe the functions and use of RTCP in IP Telephony.
66. Compare
CS telephony and VOIP in terms of principal technical differences.
67. What are the functional entities according to H.323.
Define also the main functions of the entities.
68. List the call modes supported by H.323. Draw an example of a call
mode
suitable for a call between
5 parties two of which are
connected to a
LAN and three are using a remote network connection.
69. Define the concept of Zone in H.323.
70. Describe the use of addresses in IP Telephony according to H.323.
71. Define the tasks of a gateway and a gatekeeper in H.323.
72. Describe the functions of RAS-signalling in H.323.
73. Describe the principles of call signalling in H.323.
74. Describe the functions of H.245 signalling in IP Telephony.
75. Describe the signalling flow for a GK routed (one GK) call
signalling
procedure according to H.323, show both RAS and call signalling.
76. Consider H.323 as a possible signaling
method for
proving a public telephony service. What means of control does H.323
provide
for an
operator over what a subscriber
can do?
Give your conclusion: would you invest your money in an operator that
provides
public telephony
services using H.323 and why
(assume that
technology will be available if you can make money)?
77. Compare
H.323 and SIP. Point out main architectural and design differences
.
78. Esplain the motivation why IMS has been designed
and the
objectives IMS tries to meet. Discuss also alternatives to IMS.
79. Explain the mechanism of Application triggering in 3G IMS.
80.
3G IMS network functions and their roles in controlling sessions.
81. 3G IMS architecture, elements and roles of
visited and
home networks.
82. Role and protocols supported by the HSS in 3G CN.
83. Describe the model of IMS/ISDN interworking.
84. Functional
model of a UMTS terminal.
85.
Naming according to ENUM, records in
ENUM.
86. Use of
ENUM, give an example hierarchy and a use example. Discuss also issues
open in
ENUM.
87. MEGACO
– protocol purpose, function and place in the VOIP architecture.
88. COPS – protocol purpose,
function and place in the NGN and 3G architecture.
89. Show signal flows for policy
decision and enforcement using COPS.
90. SDP – protocol purpose and
carried information.
91. Describe types of NATs.
Discuss different approaches for NAT traversal.
92. Describe the purpose of the STUN
protocol and the STUN protocol principles.
93. Describe the purpose of the TURN
protocol and the TURN protocol principles.
94. Describe the Diameter principle
architecture, documents and protocol features. Give Examples of
Diameter
applications.
95. Describe how Diameter
scalability has been enhanced. Explain the functions of the
intermediate
elements.
96. Explain the Diameter operation
model.
97. Diameter element types and the
functions supported in each element.
98. Diameter base protocol requests
and answers.
99. Describe the Diameter/NASREQ
application.
100. Describe the purpose and
operations in the Diameter SIP application.
SIP
101. SIP entities and the basic
session invitation procedures in the generic SIP as defined by IETF.
102. Describe the structure of UA
and proxy in SIP. Describe also the different types of proxies in SIP.
103. Explain the principle of event processing
in SIP (what kinds of event sequences are possible).
104. Describe the SIP message
structure.
105. The purpose and use of the main
header fields in SIP.
106. Explain SIP message routing and
the headers that are used to support SIP message routing.
107. How are loops prevented in SIP.
108. Use of the PRACK and UPDATE
methods in SIP.
109. Explain the SUBSCRIBE/NOTIFY
mechanism in SIP. Give a use example.
110. Functional entities, their roles and
capabilities according to 3G SIP
111. Discuss business threats to 3G
IMS.
112. Explain the state-of-the art in
Emergency calls and Emergency call requirements in 3G and VOIP.
SCTP and SS7 over
IP
113. SCTP features and motivation.
Why was TCP not enough?
114. SCTP associations and the
header structure.
115. Describe association
establishment in SCTP.
116. Modes of data transfer in SCTP
– sequencing and reliability.
117. SUA features and linkage to
SS7.
118. M3UA features,
linkage to SS7 and a use example.
119. Layer2 solutions for SS7 over
IP. Options, features and a use example.
Guest lecture on NGN by
Miguel Martin
120. Discuss the main technical ideas behind the development of
NGN.
121. Discuss the benefits and drawbacks of NGN from the point of view of (a) a Fixed Network operator, (b) an operator that owns both a Fixed and a Mobile Network and (c) a pure
Mobile Operator. Give some argument whether NGN will happen or not.
122. Describe the relationship of NGN and IMS and discuss the
impact of NGN on IMS.
123. Describe the Transfer Functions in NGN
124. Describe the Network Attachement SubSystem in NGN on the
level of functions.
125. Describe the Resource and Admission Control in NGN on the
level of functions.