Aastra Telecom 41-001343-02 manual DNS Query Setting, Address of the proxy

Advanced Operational Parameters

GRUU and sip.instance Support

Parameter –	Configuration Files
sip gruu	aastra.cfg, <model>.cfg, <mac>.cfg
Description	Enables or disables Globally Routable User-Agent URI (GRUU) support on the IP Phone
	according to draft-ietf-sip-gruu-15. If this parameter is disabled, parsing of inbound
	GRUU's for transfer are still enabled.
Format	Boolean
Default Value	1	(enabled)
Range	0	(disabled)
	1	(enabled)
Example	sip gruu: 0

DNS Query Setting

Parameter–	Configuration Files
sip dns query type	aastra.cfg, <mac>.cfg
Description	Specifies the Domain Name Service (DNS) query method to use when the IP
	Phones issue requests for DNS records using one of three methods: “A” only, SRV& A, and
	NAPTR & SRV & A.
Format	Integer
Default Value	1
Range	A only - The phone issues requests for “A” (Host IP Address) records from the DNS server to
	get the IP address, and uses the default port number of 5060.
	SRV & A - The phone issues requests for “SRV” (Service Location Record) records from the
	DNS server to get the port number. Most often, the IP address is included in the response
	from the DNS server to avoid extra queries. If there is no IP address returned in the response,
	the phones send out the request for “A” records from the DNS server to find the IP address.
	NAPTR & SRV & A - First, the phone sends "NAPTR" (Naming Authority Pointer) lookup to get
	the “SRV” pointer and service type. For example, if Global SIP transport protocol on the
	phone is “UDP”, and Proxy server on the phone is “test.aastra.com”, then:
	• If the NAPTR record is returned empty, the phone will use the default value
	“_sip._udp.test.aastra.com" for the “SRV” lookup.
	• If the NAPTR record is returned "test.aastra.com SIP+D2U .... _sip._udp.abc.aastra.com",
	the phone will use “_sip._udp.abc.aastra.com" for the “SRV” lookup.
	• If the NAPTR record is returned "test.aastra.com SIP+D2T .... _sip._tcp.test.aastra.com",
	where the service type TCP mismatches the phone configured transport protocol “UDP”,
	the phone will ignore this value and use the default value “_sip._udp.test.aastra.com" for
	the “SRV” lookup.
	Note:
	The phone does not use the service type sent by the NAPTR response to switch its transport
	protocol, nor does it use the NAPTR response to determine whether to use a secure or unse-
	cure communication path. The phone will always use a global sip protocol that is configured
	on the phone via configuration files or web user interface.
	After performing NAPTR, the phone sends “SRV” lookup to get the IP address and port
	number. If there is no IP address in the “SRV” response, then it sends out an “A” lookup to get
	it.
	Note:
	On the phone side, if you configure the phone with a Fully- Qualified Domain Name (FQDN)
	proxy and specified port, the phone always sends “A only” lookups to find the Host IP
	Address of the proxy.
Example	sip dns query type: 2

A-211 41-001343-02 REV04 – 05.2014