688688
310
Zoom out
Zoom in
Previous page
1/421
Next page
Chapter 23 Voice
VMG/XMG Series User’s Guide
310
4 User Agent 2 sends a response back to Proxy 2 indicating that the phone is ringing. The response is
relayed back to User Agent 1 via Proxy 1.
5 User Agent 2 sends an OK response to Proxy 2 after the call is answered. This is also relayed back to User
Agent 1 via Proxy 1.
6 User Agent 1 and User Agent 2 exchange RTP packets containing voice data directly, without involving
the proxies.
7 When User Agent 2 hangs up, he sends a BYE request.
8 User Agent 1 replies with an OK response confirming receipt of the BYE request, and the call is
terminated.
Voice Coding
A codec (coder/decoder) codes analog voice signals into digital signals and decodes the digital
signals back into analog voice signals. The Zyxel Device supports the following codecs.
G.711 is a Pulse Code Modulation (PCM) waveform codec. PCM measures analog signal amplitudes
at regular time intervals and converts them into digital samples. G.711 provides very good sound
quality but requires 64 kbps of bandwidth.
G.726 is an Adaptive Differential PCM (ADPCM) waveform codec that uses a lower bitrate than
standard PCM conversion. ADPCM converts analog audio into digital signals based on the difference
between each audio sample and a prediction based on previous samples. The more similar the
audio sample is to the prediction, the less space needed to describe it. G.726 operates at 16, 24, 32 or
40 kbps.
G.729 is an Analysis-by-Synthesis (AbS) hybrid waveform codec that uses a filter based on information
about how the human vocal tract produces sounds. G.729 provides good sound quality and reduces
the required bandwidth to 8 kbps.
Voice Activity Detection/Silence Suppression
Voice Activity Detection (VAD) detects whether or not speech is present. This lets the Zyxel Device
reduce the bandwidth that a call uses by not transmitting “silent packets” when you are not speaking.
Comfort Noise Generation
When using VAD, the Zyxel Device generates comfort noise when the other party is not speaking. The
comfort noise lets you know that the line is still connected as total silence could easily be mistaken for a
lost connection.
Echo Cancellation
G.168 is an ITU-T standard for eliminating the echo caused by the sound of your voice reverberating in
the telephone receiver while you talk.
MWI (Message Waiting Indication)
Enable Message Waiting Indication (MWI) enables your phone to give you a message–waiting
(beeping) dial tone when you have a voice message(s). Your VoIP service provider must have a
messaging system that sends message waiting status SIP packets as defined in RFC 3842.
310


Need help? Post your question in this forum.

Forumrules
1

Forum

zyxel-vmg8623-t50a

Reset search

  • Bhag bhabTouch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.Touch and hold a clip to pin it. Unpinned clips Touch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.Touch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.Touch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour. be deleted aTouch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.fter 1 hour.Touch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.ghg GB ggygbgg Touch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.Touch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.Touch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.Touch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.b Submitted on 29-9-2022 at 03:00

    Reply Report abuse


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 ZyXEL VMG8623-T50A 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 ZyXEL VMG8623-T50A in the language / languages: English as an attachment in your email.

The manual is 14,37 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.

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