Can receive calls but can't call mobile numbers

[layzee]

Equipment used:
Netcomm NL1901ACV with mobile wireless Internet
Gigaset A580 IP cordless phone (supplied by Exetel in the past)

Information provided by Exetel:
Username/VOIP number
Password
sip server (proxy) address: sip1.exetel.com.au

I can receive calls on the VOIP handset but I can't make calls. The exception is I can make calls to (02) 8030 1000 which is one of Exetel's numbers. I have attached screenshots of the settings for both devices. Am I missing anything?

If the screenshots are too small, here are the direct links:
https://forum-attachments.s3.amazonaws. ... 419757a165
https://forum-attachments.s3.amazonaws. ... bf7e3856d9

[rasikak]

Thank you for reaching out. Please PM your customer ID or the service number so we can assist you further on your query.

[layzee]

Thanks for your reply. I have PM'd you the service number.

[rasikak]

Thanks for your reply. I have PM'd you the service number.

Thank you for providing the details as requested. We have further escalated the issue to our level 2 VoIP team and we will update you once there is an update via the email reference #16207747.