Integrated Services Isdn Broadband — Test 1

Correct Answer: B. B. Integrated services digital network
Explanation: ISDN in computer networking stands for Integrated Services Digital Network. It enables the transmission of digital data over telephone lines. It is considered as a circuit-switched telephone network system.

Correct Answer: C. C. Narrow band, broadband
Explanation: Narrowband ISDN was implemented to make digital telephone systems more impactful over analog telephone systems. It utilizes narrow band of frequencies. Narrowband is also known as Normal-ISDN. Broadband ISDN on the other hand, is a standard for transmitting voice data on larger frequency bands.

Correct Answer: B. B. False
Explanation: Basic Rate Interface (BRI) and Primary Rate Interface (PRI) are the two types of Integrated Services Digital Network (ISDN). The major difference between them is their reliability. BRI provides less reliability and low services at lower costs compared to PRI.

Correct Answer: A. A. Q.931 protocol
Explanation: ISDN (Integrated Services Digital Network) is a connection oriented network system and uses Q.931 Protocol for managing its call states. Q.931 is a signaling protocol. It can be compared to SIP but SIP is not applicable to ISDN. SIP is a 3GPP signaling protocol. H.323 is a call signaling protocol that was initially implemented in LANs. ICMP is used in routers and helps in sending error messages.

Correct Answer: C. C. Full-duplex
Explanation: ISDN provides a set of standards for maintaining different call states. It is a circuit-switched telephone network system. It acts as an interface, and only a single device can be connected to this interface. This interface is based on full-duplex mode of data transmission.

Correct Answer: A. A. SMTP (simple mail transfer protocol)
Explanation: SMTP is an upper level protocol and it provides flow control. Whereas Frame relay Protocol operates in the layer such as Data Link Layer that is at lower levels of OSI model. Thus it doesn’t provide flow control or error control. Similarly other protocols such as TCP and ICMP operate in the lower levels of the OSI model.

Correct Answer: A. A. Atm, sonet/sdh, and broadband access technology
Explanation: Some network services require larger bandwidths that could not be achieved using Frame Relay. This has led to the implementation of broadband ISDN or also known as broadband network. Broadband network and service have contributed significantly in three areas. They are ATM (Asynchronous Transfer Mode), SONET (Synchronous Optical Network)/SDH (Synchronous Digital Hierarchy), and broadband access technology.

Correct Answer: D. D. B or d
Explanation: B channel is the Bearer channel where data and voice communication is carried; D is the Delta channel that carries control and signaling information; and H channel is the High-speed communication channel that is formed by combining multiple Bearer channels. Thus B or D channels of BRI line and B channels of PRI (Primary Rate Interface) line are used for carrying X.25.