AudioCodes Mediant 1000B User Manual page 353

User's Manual
Parameter
DNS Resolve Method
dns-resolve-
method
[ProxySet_DNSResol
veMethod]
Proxy Hot Swap
is-proxy-hot-
swap
[ProxySet_IsProxyHot
Swap]
Version 7.0
Defines the DNS query record type for resolving the proxy server's host
name (FQDN) into an IP address(es).

[-1] = DNS resolution method is according to the settings of the global
parameter, ProxyDNSQueryType.

[0] A-Record = (Default) DNS A-record query is used to resolve DNS to
IP addresses.

[1] SRV = If the proxy address is configured with a domain name
without a port (e.g., domain.com), an SRV query is done. The SRV
query returns the host names (and their weights). The device then
performs DNS A-record queries per host name (according to the
received weights). If the configured proxy address contains a domain
name with a port (e.g., domain.com:5080), the device performs a
regular DNS A-record query.

[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 configured proxy address contains a domain name
with a port (e.g., domain.com:5080), the device performs a regular DNS
A-record query. If the transport type is configured for the proxy address,
a NAPTR query is not performed.

[3] MS-Lync = SRV query as required by Microsoft when the device is
deployed in a Microsoft Lync environment. The device sends a special
SRV query to the DNS server according to the transport protocol
configured in the 'Transport Type' parameter (described later in this
section):

TLS: "_sipinternaltls_tcp.<domain>" and "_sip_tls.<domain>". For
example, if the configured domain name (in the 'Proxy Address'
parameter) is "ms-server.com", the device queries for
"_sipinternaltls_tcp.ms-server.com" and "_sip_tls.ms-server.com".

TCP: "_sipinternal._tcp.<domain>" and "_sip_tcp.<domain>".

Undefined: "_sipinternaltls_tcp.<domain>",
"_sipinternal_tcp.<domain>", "_sip_tls.<domain>" and
"_sip_tcp.<domain>".
The SRV query returns the host names (and their weights). The device
then performs DNS A-record queries per host name (according to the
received weights) to resolve into IP addresses.
Note: An SRV query can return up to four host names. For each host
name, the subsequent DNS A-record query can resolve into up to 15 IP
addresses. However, the device supports up to 30 DNS-resolved IP
addresses. If the device receives more than this number of IP addresses, it
uses the first 30 IP addresses in the received list and ignores the rest.
Enables the Proxy Hot-Swap feature, whereby the device switches to a
redundant proxy upon a failure in the primary proxy (no response is
received).

[0] No = (Default) Disables the Proxy Hot-Swap feature. If a failure
occurs in te primary proxy, the device does not connect with any other
address (proxy) configured for the Proxy Set.

[1] Yes = The device sends the SIP INVITE/REGISTER message to the
first address listed in the Proxy Address table configured for the Proxy
Set. If a SIP response is received and this response code is defined in
the 'Keep-Alive Failure Responses' parameter (in this table), the device
assumes the proxy is down and sends the message again; otherwise,
Description
353 Mediant 1000B Gateway and E- SBC
17. Control Network