Communication Systems Revision Set 4

Most phone lines connecting homes to the local exchange are made of copper. Copper is widely used for phone lines because it is a good conductor of electricity and has low resistance, allowing for efficient transmission of signals. It is also relatively inexpensive compared to other materials like optical fiber. Copper has been the traditional choice for phone lines due to its reliability and cost-effectiveness.

SMTP (Simple Mail Transfer Protocol) is the correct answer because it is the primary protocol used for sending email messages across the Internet. SMTP is responsible for the transmission of email from the sender's email client to the recipient's mail server. It ensures that the email is properly formatted and delivered to the correct destination. POP (Post Office Protocol) and IMAP (Internet Message Access Protocol) are used for receiving email, while IP (Internet Protocol) is a network protocol used for routing data packets across the Internet.

The correct answer is 8PA=. MIME base64 encoding is a method used to encode binary data into ASCII characters. In this encoding, each 3 bytes of data are represented by 4 ASCII characters. The given data 1111000011110000 has 16 bits, which is equivalent to 2 bytes. So, it will be encoded as 8 bits (1 byte) followed by padding. The binary representation of 8 is 1000, which is equivalent to the ASCII character '8'. The padding is represented by '='. Therefore, the series of characters representing the given data is '8PA='.

A telephony board is the hardware that allows a computer to connect to multiple PSTN telephone lines. It is specifically designed for telephony applications and provides the necessary interface and functionality to integrate telephone lines with the computer system. This board enables the computer to handle voice communication, call management, and other telephony-related tasks. Unlike a voice modem, which is designed for individual phone line connections, a telephony board is capable of handling multiple lines simultaneously, making it suitable for applications that require connecting many PSTN telephone lines to a computer.

A hierarchical system of OGMs best describes menus within voicemail systems. This means that the menus are organized in a hierarchical structure, where each level represents a different option or action. The user can navigate through the menus by selecting different options or actions, leading them to different levels or screens. OGMs, or outgoing messages, are the recorded messages that guide the user through the menu options. This hierarchical system allows for a more organized and efficient navigation within the voicemail system.

Pressing the 0 key is the quickest way to speak to an operator when using an IVR system. This is because the 0 key is usually designated as the "operator" or "customer service" key in IVR systems, allowing users to bypass the automated options and connect directly with a live operator for assistance.

The correct answer is that the Internet is free. This is because VoIP (Voice over Internet Protocol) uses the Internet to transmit voice calls, and the cost of using the Internet is typically included in a user's existing Internet service plan. Unlike traditional long distance calls that require separate charges for the distance covered, VoIP allows for cheaper long distance calls as the cost is primarily determined by the user's Internet service provider rather than the distance of the call.

During a telephone call made from a standard PSTN home telephone, the audio is digitized at the exchange. This means that the analog audio signals from the home phone are converted into digital signals at the exchange before being transmitted over the network. The exchange is responsible for converting the analog signals into digital format, allowing for efficient transmission and processing of the audio data.

The path an email message takes during its journey from sender to receiver can be determined by examining trace fields within the content of the message. These trace fields provide information about the route the message has taken, including the various servers it has passed through. By analyzing these trace fields, one can track the message's path and identify any potential issues or delays encountered along the way. Identification fields within the content of the message may contain information about the sender and recipient, but they do not provide details about the message's route. Similarly, trace fields within the envelope of the message may contain information about the message's delivery, but they do not provide a complete picture of its journey.

A soft phone is an application that enables a computer to function as a VoIP phone. It allows users to make and receive phone calls over the internet using their computer. Unlike traditional hardware phones, a soft phone utilizes software to provide the necessary functionalities, such as call management, voice communication, and sometimes even video conferencing. This software-based solution is cost-effective, easily customizable, and offers flexibility in terms of features and integration with other applications. Therefore, a soft phone is the correct term for an application that allows a computer to be used as a VoIP phone.