9.2 Voice over IP (VoIP) Q + A (Network)

What is jitter? How does it affect VoIP calls?

A jitter is a measuring time difference in packet inter-arrival time. Jittering creates odd noises trying to maintain a stable signal.

What happens if there is too much latency in a VoIP call?

Can slow down conversations and also lead to the talk over effect where one speaker interrupts the other unknowingly.

What is the function of a codec?

Codec is a compression formula that define how an image is both compressed and decompressed.

How is a VoIP gateway used?

Converts voice and fax calls between the PSTN and your IP network in real time. VoIP gateways can be placed in geographically separated branch offices to save long-distance PSTN charges.

What is the difference between a hard VoIP phone and a soft VoIP phone?

Hard phone: >Have the look and feel of a traditional phone. >Really computers that are built to look and operate like phones. >Connected to a network, just like any other computer. >Can be configured using a web browser connected to their web page interface. Soft phone: >Is a software application that is installed on a computing device like a computer or a handheld device. >Allows access to the VoIP server for real time audio communication.

Why is quality of service (QoS) important for VoIP?

QoS can assign priority of depending on the type of network traffic. Network devices like switches and routers can examine the type of service bits and precedence bits in the header of an IP packet to determine the type of traffic.

What is the most common open source VoIP protocol?

Session initiation protocol (SIP).

How does VoIP differ from traditional phone service?

Some advantages include reduced cost and using an existing network. The disadvantages include increased delay, inconsistent quality, jitter, packet loss, echo, and power loss.

What are the functions of a VoIP server? What are other names for a VoIP server?

VoIP servers have many functions such as call waiting, call transfer, conferencing, and voice mall. Other names may be hard phone, jitter, IP-PBX, QoS.