9.2 Voice over IP (VoIP)

What are the advantages of using VoIP compared to traditional phones? What are the disadvantages?

"Advantages:" -Administration is simplified because you maintain a single network for both data and voice instead of using a separate infrastructure for voice-only traffic -Costs are typically lower than long-distance costs over the PSTN -Adding additional phone lines is easier and less expensive than adding lines from the PSTN -Because VoIP packets are regular IP packets, encryption is easily added to VoIP data "Disadvantages:" -Delay occurs when data takes a long time to arrive at the receiving device -Jitter is a variation in the delay of individual packets. Jitter causes strange sound effects as the delay of packets fluctuates -Packet loss occurs when packets do not arrive at all

Which type of network transmission is used by UC systems?

-Voice calls -Audio conferencing -Video conferencing -Desktop sharing -Instant messaging

How do delay, jitter, and packet loss affect VoIP calls?

Delay- Delays cause long pauses between speaking and receiving and can result in callers continually interrupting each other Jitter- Causes strange sound effects as the delay of packets fluctuates Packet Loss- Causes drop-outs in the conversation

Why is the Quality of Service (QoS) important for VoIP?

It ensures that voice data is given higher priority on the network to decrease the effects of delay, jitter, and packet loss

What is presence information?

It lets users inform each other of their availability for communication