Advanced Operational Parameters
41-001343-02 REV05 – 07.2014
A-215
GRUU and sip.instance Support
DNS Query Setting
Parameter
–
sip gruu
Configuration Files
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
Parameter
–
sip dns query type
Configuration Files
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 (SRV & A)
Range
0
: 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.
1:
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.
2:
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