How do I troubleshoot SMPP connectivity with Telnet?

To troubleshoot SMPP with Telnet, open a command prompt and type: telnet smpp.smsgatewaycenter.com 2775 (replace with your port). If it connects (blank screen), the server is reachable. If it fails (“Connection refused” or timeout), check your firewall, IP whitelisting, or network. Ensure your IP is whitelisted with us—details in our SMPP connection. Contact support if issues persist; Telnet confirms basic access to our SMS gateway.