User's Manual

 27
This is for redundancy, if registering to Primary SIP server
fails, the IP phone will go to Secondary SIP server for
registering.
Note:Secondary SIPserveris usedforredundancy,itcan be
left blank if there is not redundancy SIP server in user’s
environment.
OutboundProxyServer TodisplayandconfigureOutboundProxyserversettings.
An outbound proxy server is used to receive all initiating
request messages and route them to the designated SIP
server.
Note: If configured, all SIP request messages from the IP
phonewillbesenttotheoutboundproxyserver
forcefully.
TransportType TodisplayandconfigureTransporttypeforSIPmessage
 UDP: UDP is an unreliable but very efficient transport
layerprotocol.
 TCP:Reliablebutless‐efficienttransportlayerprotocol.
 TLS:SecuredandReliabletransportlayerprotocol.
 DNS‐SRV: A DNS RR for specifying the location of

services.
NAT To display and configure NAT(Net Address Translator)
settings.
 STUN: Short for Simple Traversal of UDP over NATS, a
solutiontosolveNATissues.
Note:Bydefault,NATisdisabled.










