Administrator’s Guide for W80 DECT IP Multi-Cell System
48
Description
It configures the retry times when the DNS server does not respond.
Permitted
Values
Integer from 0 to 65535
Default
2
[1]
X is the template ID. X=1-10.
[2]
Y is the server ID. Y=1-2.
[3]
If you change this parameter, the phone will reboot to make the change take effect.
[4]
X is the account ID. X=1-100.
Static DNS Cache
Failover redundancy can only be utilized when the configured domain name of the server is resolved to multiple IP
addresses. If the IP phone is not configured with a DNS server, or the DNS query returns no result from a DNS
server, you can statically configure a set of DNS NAPTR/SRV/A records into the IP phone. The phone will attempt to
resolve the domain name of the SIP server with static DNS cache.
Support for negative caching of DNS queries as described in
is also provided to allow faster failover
when prior DNS queries have returned no results from the DNS server.
Topics
Behave with a Configured DNS Server
Static DNS Cache Configuration
Behave with a Configured DNS Server
When the phone is configured with a DNS server, it will behave as follows to resolve the domain name of the
server:
l
The phone performs a DNS query to resolve the domain name from the DNS server.
l
If the DNS query returns no results for the domain name, or the returned record cannot be contacted, the values
in the static DNS cache (if configured) are used when their configured time intervals are not elapsed.
l
If the configured time interval is elapsed, the phone will attempt to perform a DNS query again.
l
If the DNS query returns a result, the phone will use the returned record from the DNS server and ignore the stat-
ically configured cache values.
When the phone is not configured with a DNS server, it will behave as follows:
l
The phone attempts to resolve the domain name within the static DNS cache.
l
The phone will always use the results returned from the static DNS cache.
Static DNS Cache Configuration
The following table lists the parameters you can use to configure static DNS cache.
Parameter
account.X.dns_cache_type
[1]
<MAC>.cfg
Description
It configures whether the phone uses the DNS cache for domain name resolution of the SIP server
and caches the additional DNS records.
Permitted
Values
0
-Perform real-time DNS query rather than using DNS cache.
1
-Use DNS cache, but do not record the additional records.
2
-Use DNS cache and cache the additional DNS records.
Default
1
Parameter
account.X.static_cache_pri
[1]
<MAC>.cfg