Technical Tip: Telegram Internet Service not working for Telegram voice call

Currently, Telegram ISDB only allows protocol 6, TCP ports 80, 443, 5222.

Traffic seen in customer logs is using protocol 17, UDP ports 1400, 40317, 56110.

Run the following command to enable UDP ports 1-65535 for Telegram ISDB.

config firewall internet-service-addition
    edit 11010249
        config entry
            edit 1
                set protocol 17
                    config port-range
                        edit 1
                    end
        end
end

Note: It is necessary to restart the 'internet-service' service using the command below in order for it to take effect.

execute internet-service refresh

Or:

execute internet-service4 refresh