Chapter 18 VoIP
EMG5324-D10A User’s Guide
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RTP Port Range
Start Port
End Port
Enter the listening port number(s) for RTP traffic, if your VoIP service provider gave you this
information. Otherwise, keep the default values.
To enter one port number, enter the port number in the Start Port and End Port fields.
To enter a range of ports,
• enter the port number at the beginning of the range in the Start Port field.
• enter the port number at the end of the range in the End Port field.
DTMF Mode
Control how the Device handles the tones that your telephone makes when you push its
buttons. You should use the same mode your VoIP service provider uses.
RFC2833 - send the DTMF tones in RTP packets.
PCM - send 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 and G.726) can distort the tones.
SIP INFO - send the DTMF tones in SIP messages.
Transport Type
Transport Type
Select the transport layer protocol UDP or TCP (usually UDP) used for SIP.
FAX Option This field controls how the Device handles fax messages.
G711 Fax
Passthrough
Select this if the Device should use G.711 to send fax messages. The peer devices must also
use G.711.
T38 Fax Relay Select this if the Device should send fax messages as UDP or TCP/IP packets through IP
networks. This provides better quality, but it may have inter-operability problems. The peer
devices must also use T.38.
Outbound Proxy
Enable Select this if your VoIP service provider has a SIP outbound server to handle voice calls. This
allows the Device to work with any type of NAT router and eliminates the need for STUN or
a SIP ALG. Turn off any SIP ALG on a NAT router in front of the Device to keep it from re-
translating the IP address (since this is already handled by the outbound proxy server).
Server Address Enter the IP address or domain name of the SIP outbound proxy server.
Server Port Enter the SIP outbound proxy server’s listening port, if your VoIP service provider gave you
one. Otherwise, keep the default value.
QoS Tag
SIP TOS Priority
Setting
Enter the DSCP (DiffServ Code Point) number for SIP message transmissions. The Device
creates Class of Service (CoS) priority tags with this number to SIP traffic that it transmits.
RTP TOS
Priority Setting
Enter the DSCP (DiffServ Code Point) number for RTP voice transmissions. The Device
creates Class of Service (CoS) priority tags with this number to RTP traffic that it transmits.
Timer Setting
Expiration
Duration
Enter the number of seconds your SIP account is registered with the SIP register server
before it is deleted. The Device automatically tries to re-register your SIP account when
one-half of this time has passed. (The SIP register server might have a different expiration.)
Register Re-
send timer
Enter the number of seconds the Device waits before it tries again to register the SIP
account, if the first try failed or if there is no response.
Session Expires Enter the number of seconds the Device lets a SIP session remain idle (without traffic)
before it automatically disconnects the session.
Min-SE Enter the minimum number of seconds the Device lets a SIP session remain idle (without
traffic) before it automatically disconnects the session. When two SIP devices start a SIP
session, they must agree on an expiration time for idle sessions. This field is the shortest
expiration time that the Device accepts.
Table 79 VoIP > SIP > SIP Service Provider (continued)
LABEL DESCRIPTION
