What Is The Relationship Between Codec And Voip - ZyXEL Communications P-2024 Series Support Notes

What is the relationship between codec and VoIP?

VoIP is the general term to refer to the sending of digitized voice information in discrete packets over public
digital network (the Internet) where other data packets can be sent at the same time. A codec determines how
much bandwidth voice packets will use. To save bandwidth usage, you would use as little bandwidth as possible
at the cost of reduced voice quality.
What codec types does P-2024 support?
The P-2024 supports the following commonly used codecs.
• G.726
• G.729 a/b voice codec
• G.711u-law voice codec
• G.711a-law voice codec
• G.723.* (Option)
Which codec should I choose?
Choose a codec that is also supported on the remote VoIP host since both ends of the VoIP connection must use
the same codec. In general, a codec with low bandwidth consumption and high voice quality is a good codec.
What do I need in order to use SIP?
The following lists the minimum requirement for running VoIP applications.
1. A high-speed Internet connection. You can connect to the Internet using a cable or DSL modem. Or subscribe
to high-speed network services such as ISDN, DSL or T-1. The bandwidth requirement varies depending on
the amount of traffic in your network.
2. A PC with VoIP software installed or an external VoIP gateway (such as an ATA or the P-2024 2602 VoIP
station ATA).
3. An account from a VoIP services provider (such as an ITSP). The account can be configured to recognize
your calls automatically, or you can require the users to enter their assigned unique account numbers.
All contents copyright (c) 2006 ZyXEL Communications Corporation.
P-2024 Support Notes
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