A Fully Qualified Domain Name (FQDN), sometimes also referred to as an absolute domain name, is a domain name that specifies its exact location in the tree hierarchy of the Domain Name System (DNS). It specifies all domain levels, including the top-level domain and is resolvable to a specific IP Address.

SkySwitch employs non-FQDN domains such as 'alpha.15611.service' for the sake of anonymity, as most of the Resellers prefer not to have their customers see a domain such as skyswitch.com in the SIP settings. In general, this is not a problem because the Outbound Proxy setting '[resellerid].hpbx.outboundproxy.com' is an FQDN domain. However, when working with SIP Trunks you may sometimes encounter equipment (including some models of Adtran or Switchvox PBX) that does not work well with the outbound proxy setting and/or will not accept non-FQDN domains. In these cases, you may need to use an FQDN domain,
If you need to use an FQDN domain for a SIP Trunk, follow these steps:

Create a CNAME Record

You must create a DNS CNAME Record for your customer's SIP Trunk. We suggest something that easily identifies the customer to you, such as 'customer1.yourdomain.com'

  1. Create a DNS CNAME Record using any domain you like (such as customer1.domain.com) and point it to your reseller outbound proxy IP {resellerid}.hpbx.outboundproxy.com.
    Example: 15611.hpbx.outboundproxy.com.
  2. Create a SIP Trunk using the domain you created as the trunk name (screenshot)

    Note that the "Domain" field in the SIP Trunk form must be a valid existing domain in your Reseller account. The SIP trunk will be linked to this domain.

  3. Configure the On-Premise equipment to use customer1.domain.com as the SIP server.
Please note that DNS CNAME Records will not work for SRV Failover.