@gumpy02 wrote: ... Linksys CM3008 ... Linksys EA6300 ... Are our modem and router aged and deteriorated ? ...
The CM3008 is still approved for use with Internet plan speeds up to 267 Mbps (see https://mydeviceinfo.xfinity.com/device/linksys-cm3008-518). Likewise, the EA6300 should still be OK for speeds up to 300 Mbps or so. What speed do you subscribe to?
Slowdowns can be caused by equipment failures, but are more often due to poor Wifi or coax connections to Comcast's network, or other signal quality problems.
Are you connecting via Wifi or Ethernet? If Wifi, it's best to switch to an Ethernet cable connection if possible. That would allow you to determine whether the problem is the Wifi signal or the link between your modem and Comcast's network.
If you want to troubleshoot this yourself, please see Connection Troubleshooting Tips. If you still need help, please provide Information Requested for Connection-Related Posts, especially downstream power levels and SNR, upstream power levels, and error log.
If you can't find the problem or you'd rather have Comcast do the troubleshooting, call them at the phone number on your bill or 1-800-Comcast, or or use one of the options on https://www.xfinity.com/support/contact-us/. If they can't fix the problem remotely, insist they send a tech out to identify the cause and correct it.
If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit unless you have their Service Protection Plan (https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast rental device, or anything outside your home, you shouldn't be charged.
