AudioCodes Mediant 800B User Manual page 1026

Parameter
DNS Query Type
configure voip > sip-definition
settings > dns-query
[DNSQueryType]
Proxy DNS Query Type
configure voip > sip-definition
proxy-and-registration > proxy-
dns-query
[ProxyDNSQueryType]
User's Manual

When the parameter is set to [2] and the INVITE fails, the
device re-routes the call according to the Standard mode [0]. If
DNS resolution fails, the device attempts to route the call to
the Proxy. If routing to the Proxy also fails, the
Redirect/Transfer request is rejected.

When the parameter is set to [2], the XferPrefix parameter can
be used to define different routing rules for redirect calls.

The parameter is disregarded if the parameter
AlwaysSendToProxy is set to 1.
Enables the use of DNS Naming Authority Pointer (NAPTR) and
Service Record (SRV) queries to resolve Proxy and Registrar
servers and to resolve all domain names that appear in the SIP
Contact and Record-Route headers.

[0] A-Record = (Default) No NAPTR or SRV queries are
performed.

[1] SRV = If the Proxy/Registrar IP address parameter,
Contact/Record-Route headers, or IP address configured in
the routing tables contain a domain name, an SRV query is
performed. The device uses the first host name received from
the SRV query. The device then performs a DNS A-record
query for the host name to locate an IP address.

[2] NAPTR = An NAPTR query is performed. If it is successful,
an SRV query is sent according to the information received in
the NAPTR response. If the NAPTR query fails, an SRV query
is performed according to the configured transport type.
Note:

If the Proxy/Registrar IP address parameter, the domain name
in the Contact/Record-Route headers, or the IP address
configured in the routing tables contain a domain name with a
port definition, the device performs a regular DNS A-record
query.

If a specific Transport Type is configured, a NAPTR query is
not performed.

To enable NAPTR/SRV queries for Proxy servers only, use
the global parameter ProxyDNSQueryType, or use the Proxy
Sets table.
Global parameter that defines the DNS query record type for
resolving the Proxy server's configured domain name (FQDN)
into an IP address.

[0] A-Record (default) = A-record DNS query.

[1] SRV = If the Proxy IP address parameter contains a
domain name without port definition (e.g., ProxyIP =
domain.com), an SRV query is performed. The SRV query
returns up to four Proxy host names and their weights. The
device then performs DNS A-record queries for each Proxy
host name (according to the received weights) to locate up to
four Proxy IP addresses. Thus, if the first SRV query returns
two domain names and the A-record queries return two IP
addresses each, no additional searches are performed.

[2] NAPTR = NAPTR query is done. If successful, an SRV
query is sent according to the information received in the
NAPTR response. If the NAPTR query fails, an SRV query is
done according to the configured transport type. If the Proxy
1026
Mediant 800B Gateway & E-SBC
Description
Document #: LTRT-10298