Chapter 10 The Service Configuration Screens
User’s Guide 119
STUN
Active Select this if all of the following conditions are satisfied.
• There is a NAT router between the WiMAX Modem and the SIP
server.
• The NAT router is not a SIP ALG.
• Your VoIP service provider gave you an IP address or domain name
for a STUN server.
• Otherwise, clear this field.
Server Address Enter the IP address or domain name of the STUN server provided by
your VoIP service provider.
Server Port Enter the STUN server’s listening port, if your VoIP service provider
gave you one. Otherwise, keep the default value.
Use NAT
Active Select this if you want the WiMAX Modem to send SIP traffic to a
specific NAT router. You must also configure the NAT router to forward
traffic with the specified port to the WiMAX Modem. This eliminates the
need for STUN or a SIP ALG.
Server Address Enter the public IP address or domain name of the NAT router.
Server Port Enter the port number that your SIP sessions use with the public IP
address of the NAT router.
Outbound Proxy
Active Select this if your VoIP service provider has a SIP outbound server to
handle voice calls. This allows the WiMAX Modem 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 WiMAX Modem 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.
NAT Keep Alive
Active Select this to stop NAT routers between the WiMAX Modem and SIP
server (a SIP proxy server or outbound proxy server) from dropping the
SIP session. The WiMAX Modem does this by sending SIP notify
messages to the SIP server based on the specified interval.
Keep Alive with
SIP Proxy Select this if the SIP server is a SIP proxy server.
Keep Alive with
Outbound Proxy Select this if the SIP server is an outbound proxy server. You must
enable Outbound Proxy to use this.
Keep Alive
Interval Enter how often (in seconds) the WiMAX Modem should send SIP notify
messages to the SIP server.
MWI (Message Waiting Indication)
Enable Select this if you want to hear a waiting (beeping) dial tone on your
phone when you have at least one voice message. Your VoIP service
provider must support this feature.
Table 37 VOICE > Service Configuration > SIP Settings > Advanced (continued)
LABEL DESCRIPTION