Forum Discussion

Tcox's avatar
Tcox
New Contributor III
2 months ago

Replacement for Arris cornerstone NIU

My Cox internet connection is via a legacy Arris NIU. The coax from the street connects to the Network port and the coax feeding my cable modem connects to the Home port. There are a couple of voice ports which are disconnected since I have my own VOIP provider and a separate box for that on my LAN.

I have some noise on my network so I think removing this obsolete equipment and replacing it with a simpler junction box is probably a good idea. I think the NIU must provide some type of filtering and surge/lightning protection so I don't think you can just screw the two ends of coax together with a grounded coupler. 

Does anyone know what these old boxes are replaced with when all you need is the cable connection for internet? 

 

  • Tcox's avatar
    Tcox
    New Contributor III
    13 days ago

    Tired of waiting, I pulled the NIU and put in a grounding block, and put my garage back in order.
    The CM numbers are within the recommended ranges across all channels with no errors so far:
    Downstream +8 to -8 dBmv (meas -2.2 to -4.3dBmv)
    Upstream 40 to 50 dB (meas 45 to 47dBmv)
    SNR 35 to 45dB (meas 40 to 42dB)

    Looks like I didn't need a service call for this.

  • WiderMouthOpen's avatar
    WiderMouthOpen
    Esteemed Contributor II
    2 months ago

    I saw this previous post which pointed to a possible ground hum issue. Did you ever get that looked at and fixed? I know you likely have, since it was 10 years ago, but that would line up around the time Cox used NIU's, so it's possible a tech hasn't been out in that long.

    • Tcox's avatar
      Tcox
      New Contributor III
      2 months ago

      Old issue no longer relevant as I don't have that equipment or get TV from cable. 

      • WiderMouthOpen's avatar
        WiderMouthOpen
        Esteemed Contributor II
        2 months ago

        So you have a direct connection from the NIU output to the modem/gateway? If so, there is unlikely to be any problem with removing the NIU. I had one when I had Cox and they removed mine and if anything, it only helped things.

  • WiderMouthOpen's avatar
    WiderMouthOpen
    Esteemed Contributor II
    2 months ago

    Should just need a grounding block, assuming the NIU was correctly grounded. However the NIU is Cox property so just contact them to come out and remove it and do everything required. No replacement since it isn't used anymore and serves no function. If anything, it just causes problems. I am surprised it's still there. When was the last time you had a technician out?

    • Tcox's avatar
      Tcox
      New Contributor III
      2 months ago

      The box would have been removed long ago except it is inside the garage so they did not see it or think to ask. I would gladly pull it and put it a grounding block myself but since the NIU has voice ports/splitters, it will likely change my signal levels when pulled. I will get a tech out to look at that. 

      • WiderMouthOpen's avatar
        WiderMouthOpen
        Esteemed Contributor II
        2 months ago

        What do you mean by voice port/splitter? It has female RJ11 connections of course, because that is where you phone line used to connect to, but now it comes from your phone modem(eMTA) so the ones on the NIU aren't needed. There is a splitter/tap inside the NIU and I even think a low powered amp too. However the NIU was powered with electricity that was sent over the coaxial when the NIUs were used, but now that Cox doesn't, they no longer have the equipment on the line to send electricity through the coaxial to power it. So basically it's a paperweight but one with a splitter inside. So yes, removing it will change your signal but it should just make it stronger/clearer. The only problem that would lead to is if the signal going to your house was already too strong or you were using a amp inside to boost it. I suggest having a technician remove it and then look at your signal levels. For more info, what model modem/gateway do you have?