Chapter 9

Analog data must be converted to digital before transmission for packet switching. T/F

T

Circuit switching connections ________.

are transparent

X.25 is the standard protocol used for traditional ________ networks

packet switching

A ________ can convert a stream of digitized voice bits into packets.

softswitch

________ switching involves the partitioning of a lower speed bit stream into pieces that share a higher speed stream with other bit streams. The individual pieces are manipulated by control logic to route data from input to output.

Time division

________ switching is used in public telephone networks.

Circuit

Circuit switching is very efficient in handling digital data. T/F

F

Circuit switching connections do not appear to attached devices as direct connections. T/F

F

Circuit switching remains one of the few effective technologies for long distance communications. T/F

F

Node-node links are usually multiplexed using either frequency division multiplexing or time division multiplexing. T/F

F

Priorities cannot be used with packet switching. T/F

F

The packet switching network is a distributed collection of packet switching nodes. Because the nodes are distributed, there is a time delay between a change in status in one portion of the network and knowledge of that change elsewhere. T/F

F

Typically standards for packet-switching network interfaces do not define a virtual circuit service. T/F

F

________ switching was designed to provide a more efficient facility for bursty data traffic. The attached stations must organize their data into packets for transmission.

Packet

Another well known application of circuit switching is the PBX. T/F

T

Circuit switching and packet switching are traditional approaches to wide area network design. T/F

T

Circuit switching is the basis for private networks built on leased lines and using on site circuit switches. T/F

T

Each packet contains some portion of the user data plus control information needed for proper functioning of the network. T/F

T

Elaborate algorithms are used to cope with the time delay and overhead penalties of network operation in a packet switching network. T/F

T

With circuit switching, switching and transmission resources within the network are reserved for the exclusive use of the circuit for the duration of the connection. T/F

T

A switching center that directly supports subscribers is known as ________.

an end office

Communication via circuit switching involves three phases: circuit establishment, data transfer and ________.

circuit disconnect

With ________ a dedicated path is established between two stations for communication.

circuit switching

Each station in a network connects to a node, and the collection of nodes is referred to as a ________ network.

communications

In the ________ approach in packet switching each packet is treated independently with no reference to packets that have gone before

datagram

Dynamic use of bandwidth is utilized with ________.

datagram packet switching and virtual circuit packet switching

With internal ________ each packet is treated independently and packets intended for the same destination may follow different routes.

datagrams

The function of the __________ is to provide a transparent signal path between any pair of attached devices

digital switch

A specific preplanned route through the network between two stations is a(n) ________ virtual circuit.

internal

With ______ virtual circuits a route is defined between two endpoints and all packets for that virtual circuit follow the same route.

internal

The ________ element represents the functions and hardware needed to connect digital devices such as data processing devices and digital telephones to the network.

network interface

Three types of delays are: propagation delay, transmission time and ________ delay.

node

On a network, the switching devices whose purpose is to provide communication are called ________. These are connected to one another in some topology by transmission links.

nodes

Flexibility, resource sharing, robustness, and responsiveness are all advantages of ________ switching.

packet

With packet switching, a station transmits data in small blocks called ________.

packets

The ________ level deals with the physical interface between an attached station and the link that attaches that station to the packet switching node.

physical

A ________ is a general purpose computer running specialized software that turns it into a smart phone switch. These cost significantly less than traditional circuit switches and can provide more functionality.

softswitch

A _________ switch is one in which the signal paths are physically separate from one another. Each connection requires the establishment of a physical path through the switch that is dedicated solely to the transfer of signals between the two endpoints.

space division

In a ________ network, data entering the network from a station are routed to the destination by being switched from node to node.

switched communication

The branches between exchanges are called ________. They carry multiple voice frequency circuits using either FDM or synchronous TDM.

trunks

A key distinguishing element of packet switching networks is whether the internal operation is datagram or ________.

virtual circuit

The term ________ refers to the logical connection between two stations through the network

virtual circuit

Circuit switching is a transparent service. T/F

T

The devices attached to a network are referred to as ________. These may be computers, terminals, telephones or other communicating devices.

stations

Circuit switching was developed to handle ________ traffic.

voice