Review Questions

1.         Which term corresponds to the following definition: "Network intended for concentrating information flows arriving through multiple links from the equipment of the end users"?

A.     Backbone

B.     Access network – correct answer

C.     Core network

D.     Operating network

2.         Give examples of the data centers of different types of
telecommunications  networks.

3.         List the main requirements for access and backbone networks.

4.         List the types of clients that communications carriers may have.

5.         When can a carrier network be named a corporate network?

On the one hand – never, because of traditional network classification. On the other hand, you can name it so almost always as a carrier network almost always accomplish intra-corporate functions for a carrier corporation.

6.         What are the main characteristics of communications carrier networks?

7.         Are leased line services traditional or a fairly new development for telecommunications carriers?



8.         What additional services are offered by a competitive carrier just starting its business for attracting clients?

9.         What is the difference between Tier 1 and Tier 2 ISPs?

10.    What kind of service provides Internet access?

11.    Is it possible for a communications carrier to provide Internet access without owning any communications links?

12.    Establish the correlation between the descriptions of networks and their types (one network type is not described).


Network type

Companywide network

Campus network

Department network

Telecommunications carrier network

Used by a group of employees (100–150 users).

All network users are solving a particular business task.

Based on a single technology.







Thousands of computers, hundreds of servers.

High heterogeneity level of computers, communications equipment, operating systems, and applications.

WAN links are used.














Connects smaller networks within the limits of a building.

No WAN links.

Services give all employees access to company databases.












13.    In what kind of networks (companywide or ISP) is the share of LANs greater?

In companywide networks

14.    What are hierarchical levels into which a companywide network can
be divided?

Lowest layer of a companywide network consists of department and workgroup networks; next layer consists of building and campus networks; and top layer consists of a backbone network.  

15.    List the kinds of ISP specializations.

Internet Service Provider (ISP), Internet Content Provider (ICP), Hosting Service Provider (HSP), Content Delivery Provider (CDP), Application Service Provider (ASP), Billing Service Provider (BSP).


16.    If a corporate network has a persistent connection to the Internet, does this mean that it is a part of the Internet?


1.         How can a competitive local carrier provide individual clients access to the resources of its network?

By leasing of local loops from an incumbent local exchange carrier; or by concluding a contract with an incumbent local exchange carrier for routing clients’ requests for specific services to competitive carrier network.  

2.         Which problems had to be solved to demonopolize the telecommunications industry?

3.         Describe the Virtual Private Network service for telephone subscribers.

The main feature of telephone VPNs is that users from an organisation which uses a public provider’s telephone service instead of its own private PBX can enjoy something very close to PBX functionality. For example, they can dial using convenient private (usually short) numbers; certain phones can be fully or partly isolated from the public telephone network; users can use a PBX-style set of extended telephone services like call forwarding, call rerouting, voice mail etc.

4.         Describe the sequence of steps that company management has to take to make the company an ISP and to start providing services to its clients.

5.         An ISP owns a backbone and access networks. To which kind of network is it expedient to connect a new data center?

To a backbone in order to provide all the Internet users with high-speed access to a data centre information recourses, both to provider’s own recourses and to hosted recourses of users.