How to send massage to mobile number if any port down/up or device reboot?

How to send massage to mobile number if any port down/up or device reboot?

Take a look to https://docs.librenms.org/#Alerting/

Also, most cell phone providers have email gateways for sms. (some more reliable than others) https://teamunify.uservoice.com/knowledgebase/articles/57460-communication-email-to-sms-gateway-list