AudioCodes Mediant 500 E-SBC User Manual page 719

User's Manual
Parameter
Web/EMS: DNS Query Type
CLI: dns-query
[DNSQueryType]
Web: Proxy DNS Query Type
CLI: proxy-dns-query
[ProxyDNSQueryType]
Version 6.8

When this parameter is set to [2], the XferPrefix parameter
can be used to define different routing rules for redirect
calls.

This 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.
Notes:

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 Set 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 IP address parameter contains a domain name with
port definition (e.g., ProxyIP = domain.com:5080), the
719
53. Configuration Parameters Reference
Description
Mediant 500 E-SBC