Can I use a single DECA adapter to go from coax to ethernet to laptop?how

[patrickscott]

Greetings,

Background: I don't understand the difference between modems and DECAs.

Having cut the cable, the only service I now have is internet service coming in through a coax cable.

Current Setup (cheap & working perfectly):

I have two DECAs (DIRECTV Broadband DECA Ethernet to Coax Adapter (DCA2SR0 ) Generation II) set up as follows:

From outside coming in coax (in office upstairs) -->modem -->ethernet cable -->router (for wifi)-->ethernet cable -->powered DECA#1 -->coax cable (in wall to downstairs TV room) -->powered DECA#2 -->ethernet cable -->Roku-->HDMI -->TV

Question: Why doesn't the following setup work for me to have internet through coax cable only --no wifi?

From outside coming in coax (in office upstairs) -->connected by a barrel connector to a coax cable (in wall to downstairs TV room) -->DECA#2 (downstairs) -->ethernet cable -->Roku-->HDMI -->TV

It seems to me that since the DECA#2 (downstairs) is converting the ISP coax signal to an ethernet signal, that the modem, router (no wifi), and powered DECA(upstairs) adapter could be eliminated, and still receive a wifi signal.

Is there something that the modem does that the DECA does not? From what I have read, both the modems and the DECAs convert the coax signal to ethernet signal. Does the modem have to do somekind of handshake or something else in order to receive a usable ISP signal via the coax cable?

Thanks!

 

[abailey]

Is there something that the modem does that the DECA does not? From what I have read, both the modems and the DECAs convert the coax signal to ethernet signal. Does the modem have to do somekind of handshake or something else in order to receive a usable ISP signal via the coax cable?

Yes because the signal coming into your house is not DECA. I won't go into what signal is used from your cable company but it is not DECA. You must have your modem in place to convert the signal coming into your house to Ethernet. Now you could try doing as you suggest but putting your modem downstairs instead of the DECA #2 and essentially having the signal coming in from outside and directly to your modem in the TV room. That may or may not work depending on the signal strength (which depends on your cable type, length, and type of connectors).

 

[patrickscott]

Yes because the signal coming into your house is not DECA. I won't go into what signal is used from your cable company but it is not DECA. You must have your modem in place to convert the signal coming into your house to Ethernet. Now you could try doing as you suggest but putting your modem downstairs instead of the DECA #2 and essentially having the signal coming in from outside and directly to your modem in the TV room. That may or may not work depending on the signal strength (which depends on your cable type, length, and type of connectors).

Thanks for the clarification. So, basically, the signal coming from the ISP through the coax cable is, for all practical purposes for all devices, 'useless' until it is converted by a modem to a type of signal that a DECA , or a MOcA, or a router understands/can process. Thanks again.