How to setup DNS SRV

Feature Introduction

The DNS-SRV allows administrators to use several servers for a single domain, to move services from host to host with little fuss, and to designate some hosts as primary servers for a service and others as backups. If for some reason the ‘host’ with the highest priority cannot be reached, the SIP phone or proxy trying to reach the user within the domain will attempt to reach the next host defined within the SRV record.

In short, DNS-SRV allows users to have uninterrupted phone service when one of the call servers is temporary unavailable, for example sometimes the server is needed to be taken offline for maintenance.

DNS-SRV Process

If DNS-SRV is selected for transport type by Akuvox IP phone, the IP phone will be sending NAPTR lookup to obtain SIP server IP address, port, and transport type. It will follow the following procedure.

1.Sending NAPTR lookup.

2.If the server does not respond with NAPRT record, it will then send out DNS SRV to check if the any UDP, TCP, or TLD exists.

3.When receive respond from SRV request, the top priority address will be selected.

Configuration of DNS-SRV in Akuvox Phones

Login to the devices website and go to the path Account - Basic to configure.

1.Active an account.

2.Go to the SIP Account to fill in the account settings.

3.Go to the SIP server 1&2 to fill in the SIP server domain.

4.Go to the Transport Type to select the transport type as DNS-SRV.


Please refer to RFC3263 for more information about DNS-SRV