Chapter 25: Enterprise VoIP Network Management
324
AltiWare ACM 5.1 Administration Manual
Understanding VoIP Bandwidth Requirements
Before starting VoIP related configurations, it is helpful to have some understanding of
VoIP bandwidth requirements, so that you can plan your VoIP deployment properly. Also
see Chapter 24, “Network Configuration Guidelines for VoIP” on page 315.
The data network bandwidth required to carry VoIP depends on the following factors:
•
Codec and Compression—This is the encoding of analog voice to digital form,
decoding of digital form to analog wave form, and compression of digital form to a
smaller size. AltiWare supports three type of codec: G.711 (64Kbps), G.729AB
(8Kbps), G.723.1 (6.4Kbps)
•
Packet Length (Frame Size)—The size of the voice frame data (payload)
transmitted in a packet. For G.711 and G.729, you have choice of 10, 20, and 30ms
lengths. For G.723.1, the packet length is a fixed 30ms. A larger packet length
decreases the transmission overhead. However, it will increase the latency and have
a negative effect on the voice quality if a packet is lost during transmission. For
G.711 and G.729, 20ms is efficient and recommended.
•
IP Header—The IP/UDP/RTP header adds 40 octets per packet. With a packet
length of 20ms, the IP headers will require 16kbps of bandwidth in addition to
whatever codec is being used.
•
Transmission Medium—In order to travel through the IP network, the IP packet is
wrapped in another layer by the physical transmission medium. The transmission
medium, such as Ethernet, will add its own header, checksums, and spacers to the
packet. With a packet length of 20ms, the transmission medium requires additional
15.2kbps of bandwidth to carry the packets to their destination.
•
Silence Suppression—You can suppress the transmission of data during periods of
silence. This can reduce the demand for bandwidth by as much as 50 percent.
However, it may have a negative impact on the voice quality. Some users may feel
the conversation is not "natural" when artificial comfort noise is generated during
periods of silence.
The following table lists bandwidth requirements for various transmission media with
different codecs and frame sizes. It assumes silence suppression is not turned on. (The
same table appears on page 315.)
VoIP Bandwidth requirement for WAN connection varies depending on the type of WAN.
Bandwidth requirement typically is less than Ethernet requirement.
Summary of Contents for AltiWare ACM 5.1
Page 1: ...AltiWare ACM 5 1 Administration Manual 7 2007 4413 0001 5 1...
Page 14: ...xii AltiWare 5 1 Administration Manual...
Page 16: ...2 AltiWare ACM 5 1 Administration Manual...
Page 34: ...Chapter 1 Overview 20 AltiWare ACM 5 1 Administration Manual...
Page 54: ...Chapter 2 Software Installation License Registration 40 AltiWare ACM 5 1 Administration Manual...
Page 100: ...Chapter 5 Gateway Management 86 AltiWare ACM 5 1 Administration Manual...
Page 106: ...Chapter 6 Voice Mail Configuration 92 AltiWare ACM 5 1 Administration Manual...
Page 136: ...Chapter 10 Application Extension Configuration 122 AltiWare ACM 5 1 Administration Manual...
Page 160: ...Chapter 11 Board Configuration 146 AltiWare ACM 5 1 Administration Manual...
Page 188: ...Chapter 12 Trunk Configuration 174 AltiWare ACM 5 1 Administration Manual...
Page 194: ...Chapter 13 In Call Routing Configuration 180 AltiWare ACM 5 1 Administration Manual...
Page 206: ...Chapter 14 Out Call Routing Configuration 192 AltiWare ACM 5 1 Administration Manual...
Page 238: ...Chapter 15 Extension Configuration 224 AltiWare ACM 5 1 Administration Manual...
Page 246: ...Chapter 16 Setting Up IP Extensions 232 AltiWare ACM 5 1 Administration Manual...
Page 262: ...Chapter 18 Mobile Extension Configuration 248 AltiWare ACM 5 1 Administration Manual...
Page 280: ...Chapter 20 Paging Group Configuration 266 AltiWare ACM 5 1 Administration Manual...
Page 284: ...Chapter 21 Line Park Configuration 270 AltiWare ACM 5 1 Administration Manual...
Page 328: ...Chapter 23 Managing and Using MeetMe Conference 314 AltiWare ACM 5 1 Administration Manual...
Page 372: ...Chapter 26 System Report Management 358 AltiWare ACM 5 1 Administration Manual...
Page 392: ...Chapter 27 Microsoft Exchange Integration 378 AltiWare ACM 5 1 Administration Manual...
Page 400: ...Chapter 28 TAPI Integration 386 AltiWare ACM 5 1 Administration Manual...
Page 416: ...402 AltiWare ACM 5 1 Administration Manual...
Page 439: ...Appendix C Network Ports AltiWare ACM 5 1 Administration Manual 425 TCP 10064...
Page 440: ...Appendix C Network Ports 426 AltiWare ACM 5 1 Administration Manual...