Hello,
You will need to be more specific, what is the set up that you want to achieve or are you trying to access some application? Teltonika uses all of the standard ports for certain applications: 80 for HTTP, 443 for HTTPS, 22 for SSH, etc. However, if none of the well known ports suit your needs, you can try using any port above 1024 as to not interfere with other applications.
Best regards,
Žygimantas