Our IMS clients will use DNS service to resolve which transport protocol to preferr and which server provides that SIP service. Therefore we need for this purpose working DNS server with valid delegated zones. In our case we are administrating own DNS zone named ims1.sip.uniza.sk. So we will add required resource records, first we add NAPTR records and then valid SRV and A records
So, prepare your DNS records, in our case: