Yealink SIP-T19 E2 T4 Series, Administrator'S Manual

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Configuring Advanced Features
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SRV (Service Location Record)
The IP phone performs an SRV query on the record returned from the NAPTR for the host name
and the port number. Example of SRV records:
Priority Weight Port Target
IN SRV 0 1 5060 server1.yealink.pbx.com
IN SRV 0 2 5060 server2.yealink.pbx.com
Parameters are explained in the following table:
Parameter Description
Priority
Specify preferential treatment for the specific host entry. Lower
priority is more preferred.
Weight
When priorities are equal, weight is used to differentiate the
preference. The preference is from highest to lowest. Keep the same
to load balance.
Port Identify the port number to be used.
Target Identify the actual host for an A query.
SRV query returns two records. The two SRV records point to different hosts and have the same
priority 0. The weight of the second record is higher than the first one, so the second record will
be picked first. The two records also contain a port “5060”, the IP phone uses this port. If the
Target is not a numeric IP address, the IP phone performs an A query. So in this case, the IP
phone uses “server1.yealink.pbx.com" and “server2.yealink.pbx.com" for the A query.
A (Host IP Address)
The IP phone performs an A query for the IP address of each target host name. Example of A
records:
Server1.yealink.pbx.com IN A 192.168.1.13
Server2.yealink.pbx.com IN A 192.168.1.14
The IP phone picks the IP address “192.168.1.14” first.
Procedure
SIP Server Domain Name Resolution can be configured using the following methods.
Central Provisioning
(Configuration File)
<MAC>.cfg
Configure the transport method on the IP
phone.
Parameters:
account.X.sip_server.Y.transport_type
account.X.naptr_build
Web User Interface
Configure the transport type on the IP
phone.