Your Domain & SIP Proxy will need to be set to sip.nehos.com.au (180.94.236.10) to use this network.
The sip.nehos.com.au domain supports SIP signalling on UDP/TCP on port 5060
You will need to allow your Customer Premises Equipment (CPE) to allow use of the 180.94.236.0/27 and 180.94.237.0/27 for SIP signalling and RTP media.
For CPE equipment that uses STUN the signalling will be TCP or UDP protocol on port 5060.