When the send light is solid there is a solid uplink connection between you and your isp. This light is often labeled as online cable sync or signal and usually has a symbol.
Linksys Official Support Understanding The Light Behavior
Modem online light blinking. However this is not always the case. The power ds and us lights should become solidly on. Similar to routers most modems both cable and dsl have a light dedicated to the broadband connection. After the modem is connected to the cable and powered up the modems lights will blink. If the modems online light continues to blink for over 45 minutes after the power ds and us lights are solidly on this indicates that there is no internet connection. Go to your xfinity my account smartphone app.
Click on check for the link of service. Cable modems cmts internet support user pcs the send light on a cable modem indicates your upstream status. However if the situation persists for long follow these troubleshooting steps to help get your connection established properly. The ethernet link makes the data transfer possible. Log in to your comcast account. If it is continually blinking without ever going solid there are a few troubleshooting steps that can be done.
When the link light on a modem is blinking it means that there is data being transmitted between equipment such as between a computer and modem. If it is continually blinking without ever going solid in most cases it means there is an outage in your area. The send light on a cable modem indicates your uplink status. Modems have other lights besides the ethernet link light that can help one figure out whether or not the modem is working properly. When the send light is solid there is a solid upstream connection between the cable modem and the cmts. Have a check for the service interruption.