Grandstream GXW42xx User Manual - Manual (Page 44)

FIRMWARE 1.0.5.8 GXW42XX USER MANUAL PAGE 42 OF 62
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 GXW42XX 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
Layer 3 QoS
Settings
Configure the Diff-Serv value for SIP and RTP. Default is:
SIP Diff-Serv 24
RTP Diff-Serv 46
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 GXW42XX NAT traversal mechanism is activated or not. If
activated (by choosing “STUN”) and a STUN server is also specified, then the GXW42XX
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 GXW42XX 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 “STUN” with no specified STUN server, the GXW42XX will