Grandstream Networks HT818 Administration Manual page 25

Prefer Primary Selects to prefer primary SIP server. The account will register to primary Server if registration with Failover server
SIP Server expires. Default is No.
Specifies IP address (Supports both IPv4 and IPv6 addresses) or domain name of outbound Proxy, or media
Outbound gateway, or session border controller. (For example: proxy.myprovider.com, IPv4: 192.168.5.170, or IPv6:
Proxy fe80::20b:82ff:fe75:211d). It's Used by HT818 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
Backup Configures the backup outbound proxy to be used when the "Outbound Proxy" registration fails. (For example:
Outbound proxy.myprovider.com, or IP address, if any: IPv4: 192.168.5.170/ IPv6: fe80::20b:82ff:fe75:211d). By default, this
Proxy field is left empty.
Prefer Primary
If the user configures this option to "Yes", when the registration expires, the device will re-register via primary
Outbound
outbound proxy. By default, this option is disabled.
Proxy
From Domain allows users to add the actual domain name, it will override the from header.This is an optional configuration.
Allow DHCP
Option 120
Configures the HT81x to collect SIP server address from DHCP option 120. Default is No.
(override SIP
Server)
Selects transport protocol for SIP packets; UDP or TCP or TLS. Please make sure your SIP Server or network
SIP transport
environment supports SIP over the selected transport method. Default is UDP.
SIP URI
Scheme When Specifies if "sip" or "sips" will be used when TLS/TCP is selected for SIP Transport. The default setting is "sips".
Using TLS
Use Actual
Ephemeral
Controls the port information in the Via header and Contact header. If set to "No", these port numbers will use the
Port in
permanent listening port on the phone. Otherwise, they will use the ephemeral port for the connection. Default is No.
Contact with
TCP/TLS
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.
NAT Traversal
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 RFC 2915.
DNS Mode
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 HT81x is registered using the second SRV record, making an outbound call, it will try the second SRV
DNS SRV use
(registered IP) first. By default, this option is disabled and the DNS SRV will use first SRV instead of the registered
Registered IP
IP.
DNS SRV
Configure the preferred IP mode when DNS Mode is SRV or NAPTR/SRV.
Failover Mode
• Default SIP request will always be sent to the address with the top priority based on the SRV query result, even if
this address is different from the registered IP address.
• Saved one until DNS TTL SIP request will always be sent to the registered IP address until DNS TTL expires or
registered IP address is unreachable