AudioCodes Mediant 2000 User Manual page 283

SIP User's Manual
Parameter
Web: Proxy DNS Query Type
[ProxyDNSQueryType]
Web: Number of RTX Before Hot-
Swap
EMS: Proxy Hot Swap Rtx
[HotSwapRtx]
Version 5.8
address defined in the Routing tables contains a domain name
with port definition, the device performs a regular DNS A-
record query.
If a specific Transport Type is defined, a NAPTR query is not
performed.
Note: To enable NAPTR/SRV queries for Proxy servers only,
use the parameter ProxyDNSQueryType.
Enables the use of DNS Naming Authority Pointer (NAPTR)
and Service Record (SRV) queries to discover Proxy servers.

[0] A-Record = A-Record (default)

[1] SRV = SRV

[2] NAPTR = NAPTR
If set to A-Record [0], no NAPTR or SRV queries are
performed.
If set to SRV [1] and 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. Therefore, if the first SRV query
returns two domain names, and the A-record queries return
two IP addresses each, no additional searches are performed.
If set to NAPTR [2], 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.
If the Proxy IP address parameter contains a domain name
with port definition (e.g., ProxyIP = domain.com:5080), the
device performs a regular DNS A-record query.
If a specific Transport Type is defined, a NAPTR query is not
performed.
Note: When enabled, NAPTR/SRV queries are used to
discover Proxy servers even if the parameter DNSQueryType
is disabled.
Number of retransmitted INVITE/REGISTER messages before
the call is routed (hot swap) to another Proxy/Registrar.
The valid range is 1 to 30. The default value is 3.
Note: This parameter is also used for alternative routing using
the 'Tel to IP Routing' table (or 'Outbound IP Routing' table). If
a domain name in the table is resolved into two IP addresses,
and if there is no response for HotSwapRtx retransmissions to
the INVITE message that is sent to the first IP address, the
device immediately initiates a call to the second IP address.
283
6. Configuration Parameters Reference
Description
October 2009