Forum Discussion

NigelB's avatar
NigelB
New Contributor
6 years ago

How many upstream channels should I have ?

I have COX INTERNET PREFERRED 50 service with advertised speeds up to: 50 Mbps download and 5 Mpbs upload

For the past year or so I have noticed that I am only getting 1 out of 4 upstream channels locked - see below. Only channel 0 is locked.

Cable modem is Netgear CM31T. North Phoenix area.

The question is should I have all 4 upstream channels or is Cox deliberately limiting me to 1 channel because of my service level ?

Upstream Channel 0
Lock Status Locked Modulation 64QAM
Channel ID 1 Symbol rate 5120 Ksym/sec
Upstream Frequency 16900000 Hz Upstream Power 38.5000 dBmV

Upstream Channel 1
Lock Status Not Locked Modulation  
Channel ID 0 Symbol rate 0 Ksym/sec
Upstream Frequency 0 Hz Upstream Power 0 dBmV

Upstream Channel 2
Lock Status Not Locked Modulation  
Channel ID 0 Symbol rate 0 Ksym/sec
Upstream Frequency 0 Hz Upstream Power 0 dBmV

Upstream Channel 3
Lock Status Not Locked Modulation  
Channel ID 0 Symbol rate 0 Ksym/sec
Upstream Frequency 0 Hz Upstream Power 0 dBmV

7 Replies

  • NigelB's avatar
    NigelB
    New Contributor

    Replaced the CMD31T with Motorola MB7420. 

    Now getting all 4 upstream channels, better upload speeds and more reliable connection.

    Thanks everyone for your replies.

    • Bruce's avatar
      Bruce
      Honored Contributor III

      Ah...t'was a typo.

      That's quite the modem for 50 Mbps.  I wonder if its 16 channels can handle it.

  • Bruce's avatar
    Bruce
    Honored Contributor III

    Do you have the Netgear CMD31T?  You should be getting 4 up-channels.  Does Cox still have 50 Mbps plans?  Cox may have bumped you to 100 Mbps at a 50 Mbps price.  Bumping you may have caused a configuration error.

    Try recycling power on your modem for a few minutes.

  • Bruce's avatar
    Bruce
    Honored Contributor III

    If you do have an older modem (DOCSIS 2), you'll only have one channel per stream.  Also, if your plan is 5 Mbps up, that is well within the capabilities of older modems at 10 or 30 Mbps.

    Only DOCSIS 3.x modems can bond multiple channels.  I'm curious of your download speeds.  Are you getting 50 or 40 Mbps?  Does your download show multiple channels?

  • Bruce's avatar
    Bruce
    Honored Contributor III

    I failed to look closely at your log files.  You're only supposed to have 1 channel per stream.

    The header in Column-3 of your log reads 64QAM.  Only DOCSIS 2 modems support 64QAM (modulation).

    As a comparison, DOCSIS 3.x modems support 128QAM upstream.  Therefore, not only can a D3 modem bond multiple channels, but also double the bandwidth of each channel of a D2 modem.

    D2 may be all you need with a 50 Mbps plan.  If your plan has 5 Mbps up, that is well within the capabilities of older modems at 10 or 30 Mbps...even on only one channel.  I'm curious of your download speeds.  Are you getting 50 or 40 Mbps?  D2 is supposed to max at 40 Mbps.

    • Bruce's avatar
      Bruce
      Honored Contributor III

      It seems like the service level is as old as the modem but still provides an in-spec signal.  How is it not compatible?  If the only complaint is a questionable screenshot, there doesn't seem to be an issue.

      If it ain't broke...upgrade?