301455
33
Zoom out
Zoom in
Previous page
1/325
Next page
Getting Started
Ensuring Voice Quality
Cisco Small Business SPA300 Series, SPA500 Series, and WIP310 IP Phone Administration Guide 32
1
The table approximates the bandwidth budget for each side of the conversation
(in each direction) using different codecs and the number of calls the network
might support. The table is based on the following assumptions:
Bandwidth calculated with no silence suppression, as the use of silence
suppression can reduce the average bandwidth budget by 30 percent or
more.
20 millisecond of payload per RTP packet
For more information about bandwidth calculation, refer to the following web sites:
http://www.erlang.com/calculator/lipb/
http://www.packetizer.com/voip/diagnostics/bandcalc.html
Factors Affecting Voice Quality
The following factors contribute to voice quality:
Audio compression algorithm—Speech signals are sampled, quantized,
and compressed before they are packetized and transmitted to the other
end. For IP Telephony, speech signals are usually sampled at 8000 samples
per second with 12–16 bits per sample. The compression algorithm plays a
large role in determining the voice quality of the reconstructed speech
signal at the other end. Cisco SPA IP phones support popular audio
compression algorithms for IP Telephony: G.711 a-law and u-law, G.726,
G.729a, G.722 (not supported on Cisco WIP310) and G.723.1. (not
supported on the Cisco SPA525G or Cisco SPA525G2 or Cisco WIP310.)
Codec Estimated
Bandwidth
2 Calls 4 Calls 6 Calls 8 Calls
G.711 110 kbps 220 kbps 440 kbps 660 kbps 880 kbps
G.722 110 kbps 220 kbps 440 kbps 660 kbps 880 kbps
G.726-40 87 kbps 174 kbps 348 kbps 522 kbps 696 kbps
G.726-32 79 kbps 158 kbps 316 kbps 474 kbps 632 kbps
G.726-24 71 kbps 142 kbps 284 kbps 426 kbps 568 kbps
G.726-16 63 kbps 126 kbps 252 kbps 378 kbps 504 kbps
G.729 55 kbps 110 kbps 220 kbps 330 kbps 440 kbps
Downloaded from www.Manualslib.com manuals search engine
33


Need help? Post your question in this forum.

Forumrules


Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.

For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information.

Forumrules

To achieve meaningful questions, we apply the following rules:

Register

Register getting emails for Cisco spa509g ip at:


You will receive an email to register for one or both of the options.


Get your user manual by e-mail

Enter your email address to receive the manual of Cisco spa509g ip in the language / languages: English as an attachment in your email.

The manual is 2,55 mb in size.

 

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

Others manual(s) of Cisco spa509g ip

Cisco spa509g ip Additional guide - Dutch - 19 pages


The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.



Info