Grandstream Networks HT818 Administration Manual page 45

Allow DHCP Option 120
(override SIP Server)
SIP transport
SIP URI Scheme When
Using TLS
Use Actual Ephemeral
Port in Contact with
TCP/TLS
NAT Traversal
DNS Mode
DNS SRV use Registered
IP
Configures the HT818 to collect SIP server address from DHCP option 120.
Default is No.
Selects transport protocol for SIP packets; UDP or TCP or TLS. Please make sure
your SIP Server or network environment supports SIP over the selected transport
method. Default is UDP.
Specifies if "sip" or "sips" will be used when TLS/TCP is selected for SIP Transport.
The default setting is "sips".
Controls the port information in the Via header and Contact header. If set to "No",
these port numbers will use the permanent listening port on the phone. Otherwise,
they will use the ephemeral port for the connection. The default setting is "No".
Indicates type of NAT for each account. This parameter configures whether the NAT
traversal mechanism is activated. Users could select the mechanism from No, Keep-
alive, STUN, UPnP.
Default setting is No.
Selects DNS mode to use for the client to look up server. One mode can be
chosen.
•
A Record (Default): Resolves IP Address of target according to domain
name.
•
SRV: DNS SRV resource records indicate how to find services for various
protocols.
•
NAPTR/SRV: Naming Authority Pointer according to RFC2915.
•
Use Configured IP: If the SIP server is configured as domain name, device
will not send DNS queries, but will use "Primary IP" or "Backup IP" to send
SIP message if at least one of them is not empty. It will try to use "Primary
IP" first, after 3 tries without any response, it will switch to "Backup IP 1", then
"Backup IP 2", and then it will switch back to "Primary IP" after 3 retries.
When the HT818 is registered using the second SRV record, making an outbound
call, it will try the second SRV (registered IP) first. By default, this option is
disabled, and the DNS SRV will use first SRV instead of the registered IP.
HT818 Administration Guide
Version 1.0.27.2
P a g e | 44