Results 1 to 7 of 7

Thread: Linksys CM100 cable modem signal values okay?

  1. #1
    Junior Member
    Join Date
    Aug 2008
    Posts
    4

    Linksys CM100 cable modem signal values okay?

    Hi everyone! I just bought a new Linksys CM100 modem for my Comcast HSI cable. It runs surprisingly faster than my older D-Link (which I think the newer DOCSIS is the culprit) & gives me much better speeds. However, I still think I have one problem. When I try to host ANY games either via wired or wireless on either Vista or XP, I sometimes get occasional lag and spikes. I've tried disabling the Autowireless programs in the network of each OS, but sometimes I still get it.

    At first, I thought it may be just normal as my surfing/download/upload speed is superb and excellent. Then, I researched more and found that maybe some of my cable modem signal values are a little bit strange. So, entering the main modem diagnostics page located at 192.168.100.1:

    Here's what they show:

    Downstream Channel:
    Lock Status Operational
    Modulation 256QAM
    Channel ID 76
    Provisioned Rate 6600 kbps
    Symbol Rate 41879.195 Ksym/sec
    Downstream Power 9.0 dBmV
    SNR 40.0 dB


    Upstream Channel:
    Lock Status Operational
    Modulation 64QAM
    Channel ID 11
    Provisioned Rate 1100 kbps
    Symbol Rate 5120 Ksym/sec
    Upstream Power 45.0 dBmV

    I think I'm concerned with the downstream power...does it seem a little too high? Could this (or any other settings that may look a bit off) be responsible for perhaps the lag problem? Everything else on my internet runs smoothly.

    I am running on a Linksys CM100 cable modem to my first wired computer, and then a Wireless-G Linksys WRT54G V2.0 (with updated firmware & stuff) Router for the rest of the computers. There are no splitters or anything coming out of the outlet--just one coaxial cable to the modem. But, with or without the router, I still sometimes feel like my internet acts strangely when trying to host or play PC games. I haven't checked the culprit of any of the coaxial cables or RJ45 cables (maybe I need some higher quality cables or to replace them?)...but I think they're still good and not fading. The modem itself does get a little warm (I don't know if temperature is correlated with power), but probably because it's so darn small...all the chips are condensed into a small box, maybe?

    Our house also uses regular analog cable TV (they give us like 71 channels including basic ones)--no digital or cablebox though. All in all, the internet download/upload speeds are great and working just fine...maybe it's just me. Anyways, how are these values? Thanks!
    Last edited by Kabigon; 08-02-08 at 08:38 AM.

  2. #2
    Moderator YeOldeStonecat's Avatar
    Join Date
    Jan 2001
    Location
    Somewhere along the shoreline in New England
    Posts
    50,909
    Quote Originally Posted by Kabigon View Post

    I am running on a Linksys CM100 cable modem to my first wired computer, and then a Wireless-G Linksys WRT54G V2.0 (with updated firmware & stuff) Router for the rest of the computers.
    How is this setup? Doing ICS with the first machine to the Linksys?
    MORNING WOOD Lumber Company
    Guinness for Strength!!!

  3. #3
    Junior Member
    Join Date
    Aug 2008
    Posts
    4
    ICS as in Internet Connection Sharing? I am not sure if I have it enabled for the router. Is it usually on by default if I have a wireless router? How do I check?

    It seems like when I tried it without the router, the connection feels like it still lags/spikes a little in games and applications. Hmm....

    Update: I tried changing the coaxial cable to a new one (Philips RG6 Quad-shield)--it did an inverse thing. It lowered the downstream power to 8 dBmV & the SNR to 39.0 dB. All the other values remained the SAME. But, bizzare....I guess it didn't do much except lower those two by one. Should I stick back with the old one or this one?
    Last edited by Kabigon; 08-02-08 at 11:42 PM.

  4. #4

    Linksys cm100

    hmmm interesting scenario, I also have a similar problem. I run about 20up/2down, and im picking up similar lag on a ps3. I use the ps3 at my parents house with a similar bandwitdh and there is no problems there. I previously had a linksys wcg200 (router, accss pt, modem) in one and would sometimes pick up lag. (i did open all the ports, dmz, reset)nothing seemed to work. So I bought the Linksys cm100 cable modem, change out the wires, and now with a faster speedtest.net test, im picking up spikes of lag. I ran the connection straight from the source (no splitters) and that also didnt help. I have come to the conclusion I have a bad rf adapter, my modem has a high/low transmit level, or there is some kind of splice in a wire I would not be able to get to (high rise condo). So I guess my only conclusion is to try a new modem...BTW, my isp is worthless, they state as long as I am getting the speed im paying for they are doing their job. Any experts out there? any some advice would help-

    thanks

    ^^question, did you run a speed test? have you ask your isp about your problem?

  5. #5
    Junior Member
    Join Date
    Aug 2008
    Posts
    4
    Yup, I ran a speed test. The speed values looked fine. With Comcast's PowerBoost, I was getting around 12000-16000 kbps down & 1500ish kbps up. But how do you detect spikes/lags in the speedtest? Are there things to look out for or other things to try? Thanks!

  6. #6
    Moderator YeOldeStonecat's Avatar
    Join Date
    Jan 2001
    Location
    Somewhere along the shoreline in New England
    Posts
    50,909
    Quote Originally Posted by Kabigon View Post
    ICS as in Internet Connection Sharing? I am not sure if I have it enabled for the router. Is it usually on by default if I have a wireless router? How do I check?
    I'm trying to figure out your setup. You mention the modem is wired to your first computer...and then the rest of your computers use a router.

    Most broadband modems have just 1x ethernet port. So..that goes either to your computer, or the WAN/Internet port of your router.

    So how is your cable modem wired to your first computer, and your other PCs using the router?
    MORNING WOOD Lumber Company
    Guinness for Strength!!!

  7. #7
    Junior Member
    Join Date
    Aug 2008
    Posts
    4
    Oh! Here's the setup:

    The Linksys CM100 cablem modem's ethernet port is connected to the ethernet port of the Linksys Wireless-G WRT54G via a RJ45 cable. My router then has a "1, 2, 3, 4" WIRED ports for 4 more computers. However, I only use the "1" slot through another ethernet cable to the NIC on my computer.
    The other computers all use wireless. I hope this makes sense!

Similar Threads

  1. Cable modem keeps losing connection
    By zodiac88 in forum General Broadband Forum
    Replies: 5
    Last Post: 01-28-09, 03:27 AM
  2. Linksys CM100 cable modem?
    By KoRnGtL15 in forum General Broadband Forum
    Replies: 4
    Last Post: 05-09-08, 04:42 PM
  3. Cable modem keeps dropping signal
    By Stevis50 in forum General Broadband Forum
    Replies: 12
    Last Post: 04-24-08, 01:12 PM
  4. Problems with losing cable internet signal
    By twmark in forum General Broadband Forum
    Replies: 5
    Last Post: 01-13-08, 04:52 PM
  5. cable modem Xbox 360
    By GottiJr in forum General Broadband Forum
    Replies: 7
    Last Post: 04-21-07, 05:50 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •