ZyXEL ADSL Prestige 2602R-61 VoIP 91-006-024004B Manuale Utente

Prestige 2602R Series User’s Guide

112 

Chapter 8 Voice Screens

Session Expires

Use this field to set the longest time that the Prestige will allow a SIP session to 

remain idle (without traffic) before dropping it.

Min-SE

When two SIP devices negotiate a SIP session, they must negotiate a common 

expiration time for idle SIP sessions. This field sets the shortest expiration time that 

the Prestige will accept.  The Prestige checks the session expiration values of 

incoming SIP INVITE requests against the minimum session expiration value that 

you configure here. If the session expiration of an incoming INVITE request is less 

than the value you configure here, the Prestige negotiates with the other SIP 

device to increase the session expiration value to match the Prestige’s minimum 

session expiration value.

RTP Port Range

Real time Transport Protocol is used to handle voice data transfer. Use these fields 

to configure the Prestige’s listening port range for RTP traffic. Leave these fields 

set to the defaults if you were not given a range of RTP ports to use.

Preferred 

Compression 

Type

Use this field to select the type of voice coder/decoder (codec) that you want the 

Prestige to use. G.711 provides higher voice quality than G.729 but requires 

64kbps of bandwidth while G.729 only requires 8kbps.
Select G.711>G.729 if you want the Prestige to first attempt to use the G.711 

codec and then the G.729 codec if the peer is not set up to use G.711.
Select G.711 only if you want the Prestige to only use the G.711 codec when 

making VoIP calls. You will not be able to connect to a peer that is not set up to use 

G.711.
Select G.729>G.711 if you want the Prestige to first attempt to use the G.729 

codec and then the G.711 codec if the peer is not set up to use G.729.
Select G.729 only if you want the Prestige to only use the G.729 codec when 

making VoIP calls. You will not be able to connect to a peer that is not set up to use 

G.729.

DTMF Mode

The Dual Tone Multi-Frequency (DTMF) mode sets how the Prestige handles the 

tones that your telephone makes when you push its buttons. It is recommended 

that you use the same mode that your VoIP service provider uses.
Select RFC 2833 to send the DTMF tones in RTP packets. 
Select PCM (Pulse Code Modulation) to include the DTMF tones in the voice data 

stream. This method works best when you are using a codec that does not use 

compression (like G.711). Codecs that use compression (like G.729) could distort 

the tones.
Select SIP INFO to send the DTMF tones in SIP messages.

MWI

Enable Message Waiting Indication (MWI) to have your phone give you a 

message–waiting (beeping) dial tone when you have a voice message(s). Your 

voice service provider must have a messaging system that supports this feature.

Expiration 

Time

Use this field to set how long the SIP server should continue providing the 

message waiting service after receiving a SIP SUBSCRIBE message from the 

Prestige.
The SIP server stops providing the message waiting service if it has not received 

another SIP SUBSCRIBE message from the Prestige before this time period 

expires. 

Call Forward 

Table

Select which call forwarding table you want the Prestige to use to block or redirect 

calls. You can use a different call forwarding table for each SIP account or use the 

same call forwarding table for both.

Back

Click Back to return to the previous screen. 

Apply

Click Apply to save your changes back to the Prestige.

Cancel

Click Cancel to begin configuring this screen afresh.

Table 27   Voice Advanced Setup (continued)