https://itmanual.net/%ec%95%84%ec%9d%b4%ed%94%bc%ed%83%80%ec%9e%84-iptime-%ec%9d%b4%eb%a6%84-%eb%b3%80%ea%b2%bd-ssid-%eb%84%a4%ed%8a%b8%ec%9b%8c%ed%81%ac-%ec%9d%b4%eb%a6%84-%eb%b0%94%ea%be%b8%ea%b8%b0/