User's Manual

FIRMWARE 1.0.3.4 GXW42XX USER MANUAL PAGE 38 OF 56
Failover SIP
Server
Failover SIP Server’s IP address or Domain name provided by VoIP Service provider. This
server will be used if the Primary SIP server becomes unavailable.
Prefer Primary SIP
Server
Default is No. If set to yes it will register to Primary Server if registration with Failover server
expires
Outbound Proxy
IP address or Domain name of Outbound Proxy, or Media Gateway, or Session Border
Controller. Used by GXW4248
for firewall or NAT penetration in different network environments.
If symmetric NAT is detected, STUN will not work and
ONLY outbound proxy can correct the
problem.
Network Settings
DNS Mode
One from the 3 modes available for “DNS Mode” configuration:
-A Record (for resolving IP Address of target according to domain name)
-SRV (DNS SRV resource records indicates how to find services for various protocols)
-NAPTR/SRV (Naming Authority Pointer according to RFC 2915)
-Use Configured IP (If selected, please fill in Primary IP, Backup IP 1 and Backup IP 2.)
One mode can be chosen for the client to look up server.
The default value is “A Record”
Primary IP
Configures the primary IP address where the phone sends DNS query to when "Use
Configured IP" is selected for DNS mode.
Backup IP 1
Configures the backup IP 1 address where the phone sends DNS query to when "Use
Configured IP" is selected for DNS mode.
Backup IP 2
Configures the backup IP 2 address where the phone sends DNS query to when "Use
Configured IP" is selected for DNS mode.
NAT Traversal
This parameter defines whether the GXW4248 NAT traversal mechanism is activated or not. If
activated (by choosing “Yes”) and a STUN server is also specified, then the GXW4248
performs according to the STUN client specification. Under this mode, the embedded STUN
client will detect if and what type of firewall/NAT is being used. If
the detected NAT is a Full
Cone, Restricted Cone, or a Port-Restricted Cone, the GXW4248
will use its mapped public IP
address and port in all of its SIP and SDP messages.
If the NAT Traversal field is set to “Yes” with no specified STUN server, the GXW4248
will
periodically (every 20 seconds) send a blank UDP packet (with no payload data) to the SIP
server to keep the “hole” on the NAT open.
Use NAT IP
The NAT IP address used in SIP/SDP messages. It should ONLY be used if required by your
ITSP.