Jeez, thats an old slow device. Just a 8x4 modem. Rated to only 100mbps service for most ISP’s. Probably time to look at an upgrade if you have faster service. 

In terms of the light, per the manual, the link light blinks when activity is detected. So if you’re using the device, it should blink

Thanks for the info.  I must have missed the part in the manual that stated the light blinks when transferring data.

Yes it’s old, it belongs to Optimum, and I pay $10/month for it.  The only reason I haven’t bought a new one and switched over is my memory of nightmares with modems and routers.  I bought an SB6190 a few years back but it’s still in the box.  Do I have to be on the phone with Optimum if I switch over to this new modem?  I’d have to connect it to my Linksys wireless router as well.

the SB6190 would be a pretty big upgrade from the one you have. But if you’re only paying for 100mpbs, the one you have would still be fine. Just depends on what you pay for. 

you’d also have to check with optimum if its compatible. Each ISP has approved ones but sadly, optimum doesn’t list which they approve. (or I’d link it here).