Cable modem question

Texas Proud

Give me a museum and I'll fill it. (Picasso) Give me a forum ...
Joined
May 16, 2005
Messages
17,266
We have Comcast for internet and home phone.

They were out yesterday to fix a cut wire. While here I asked about our modem as we have had it for a few years... we were given a new modem...

So, my questions are varied...

Technician said that the modem can get hot if plugged into a battery backup... it does not make sense to me, but he said if it gets hot to just plug it into surge only... Well, it is hot so I plugged it into the battery backup surge only... guess what? It is still hot... I cannot find much on this modem but it is a Technicolor CGM4140COM....

Why would something run hot connected to a battery backup? And should it be running hot? My thinking is if it is running hot no matter where it is plugged I might as well have it on the battery....


Next question.... the modem has only 2 network plugs... I have my computer and my printer connected... I am looking at buying a RAID backup hard drive for all computers... but where can I plug it into? Do I need to buy a separate router just for one other item?


One of the good things it that it is dual band, so maybe my DW can get a better signal with her IPad and laptop...
 
Comcast tech award to that one.
You need a switch, or a router with multiple ports. Modem gets cabled to switch or router, all computers and backup cable in to switch or router.
 
If a battery backup puts out a lower voltage than that for which a device is designed, that device can draw more current, and more current leads to more heat. Note this might happen only while running on battery power during a line outage. Furthermore, most batteries will not power devices long enough for excess heat to be a problem. Such heat damage risk is very low, probably less than the chance the device experiences the Pepsi Syndrome.
 
First of all, if you are still renting a modem from your Internet Service Provided (ISP) then you should consider buying one instead vice renting to save some of that money.
You can get on your ISP's website and look for compatible modems that you can use to connect to their network.


As target2109 wrote, your modem would normally be cabled up (CAT6 cable) to a router (or a switch) which has multiple ports for connecting other networked devices. Is your current device a modem/router combo since you mentioned "better signal"?
 
First of all, if you are still renting a modem from your Internet Service Provided (ISP) then you should consider buying one instead vice renting to save some of that money.
I tried that a year ago. They would not turn on MOCA. I didn't have the time to take them to court, which is what it sounded like was my only option given the way things work in Georgia.
 
We have our own Netgear AC1600 router/modem to save the monthly rental.
 
Next question.... the modem has only 2 network plugs... I have my computer and my printer connected... I am looking at buying a RAID backup hard drive for all computers... but where can I plug it into? Do I need to buy a separate router just for one other item?
You can buy a Netgear switch. This will give you additional Ethernet ports. Here’s one at Amazon https://www.amazon.com/NETGEAR-Unma...?s=electronics&ie=UTF8&qid=1528023924&sr=1-11

Don’t forget to log into your Comcast account to disable the feature that lets Comcast use the modem as a hotspot.
 
Thanks all... I will buy a switch when I need it...


I will have to see about buying my own modem/gateway... did a quick look and it is costing $11 per month :mad:.... but, did not see any page that said what was compatible...


I do know that my sister had one at one time and it stopped working so she went back to Comcast's gateway so it is easy for her if something goes wrong...
 
It is true that Comcast may give you flack when they realize you have 3rd party modem. I was reluctant to do this and regret paying them additional money for so many years.
 
....I will have to see about buying my own modem/gateway... did a quick look and it is costing $11 per month :mad:.... but, did not see any page that said what was compatible...


I do know that my sister had one at one time and it stopped working so she went back to Comcast's gateway so it is easy for her if something goes wrong...

It is true that Comcast may give you flack when they realize you have 3rd party modem. I was reluctant to do this and regret paying them additional money for so many years.

I ended up buying an Arris cable modem at my local Best Buy for ~$110 rather than pay, in my case, $10/month rental.

However, beware that if you don't rent their modem and have trouble that their first response will be to blame your modem. I was having internet issues and called them and they said all was fine from their end but they could send out a tech but it would be $35 (or perhaps more, I don't remember) if it turned out that it was not their equipment. I declined because I wanted to do more diagnosing before I had a tech out. I changed out the cable between the wall and the cable modem and haven't had a problem since.
 
I would check if you can change the login credentials to the admin GUI of the gateway device. You have an all-in-one unit and it contains the firewall to your home network. There have been too many instances of ISP supplied devices having a port open to the internet, accessible with an easily found default username and password.

A quick search gave me username: admin and password: password for your device when operated by Comcast. I hope that doesn't work on your device, but I would verify.

Example: A couple of years ago my sister called me because she was having trouble setting her DSL modem to bridge mode so she could use her own router. I asked her for the manufacturer and model of the modem, and the external IP address of the modem. I looked up the default username and password (not changeable by the user for this setup), and connected to her modem from half way across the state. I logged in, set bridge mode, and the system worked. Don't depend on your ISP for home network protection.
 
This picture may be of use in trying to understand what you have and what you may implement in the future. Everything costs money, though. I've always had Comcast service, delivered through their modem(s) or mine. I have always had a wireless router and switches in my office, which take the Comcast internet, and route/switch it accordingly. If you just have a Comcast box, it delivers the wireless routing and addressing to your home devices. However, it is limited in external ports (just guessing). So, if you have need to wire in more devices, you may need at minimum a switch. However, I've seen newer Comcast modems that have more than a single port.

Below is a photo of what I have, which is probably more complicated than what a typical user wants/needs. On the right is an Arris cable modem, and on the left is a Netgear router.

1) If you just buy a replacement modem such as in photo, you will need a wireless router too.
2) If you buy a cable modem with built-in router features, then you will probably not need an additional switch. For example, this Arris modem has WiFi as well as 4 ports you can plug into.
https://www.amazon.com/ARRIS-SURFboard-SBG6580-DOCSIS-2-4Ghz/dp/B0040IUI46
So you would probably just need this one device.

Also, be aware that Comcast has a web page to help you provision a new modem that is not theirs. However, you may need to call them and wait until they provision the modem by uploading configuration to it. You need a DOCSIS 3.0 modem that is on their list to avoid their bs.
 

Attachments

  • IMG_1671a.jpg
    IMG_1671a.jpg
    57.8 KB · Views: 18
Comcast has a website that shows you their approved modems you can buy, based on your location and subscription speed. Options on the left side of screen to help you pick the right one. I'm an Arris fan myself and have owned my own modem for past 10 years of Comcast service. Good luck.

mydeviceinfo.comcast.net
 
However, beware that if you don't rent their modem and have trouble that their first response will be to blame your modem. I was having internet issues and called them and they said all was fine from their end but they could send out a tech but it would be $35 (or perhaps more, I don't remember) if it turned out that it was not their equipment. I declined because I wanted to do more diagnosing before I had a tech out. I changed out the cable between the wall and the cable modem and haven't had a problem since.
Adding to this, both DD and I had the same issue with Comcast. We both had modems that were on Comcast’s approved list (ARRIS Motorola Surfboard 5101) Comcast then changed the modem standard, declared that modem was no longer approved. When DD called to report issues with speed and availability, they said the issue was the modem and a visit by the tech was a mandatory $100 fee. The modem itself was fine and good for more years of service, but did not support Comcast’s higher bandwidth rate, which required a more expensive subscription package. She changed the modem, was not surprised when the problem continued, and eventually closed her account.

They did the exact same thing to me. It’s one of the reasons their customer base is so unhappy with them. The economics of buying vs renting still favor buying, even if one has to change modems every 3 years.
 
Another cheap fellow here that owns his own modem instead of renting one.
When I switched from WOW to Comcast, the comcast fellow just phoned in my modem mac address to their office, and in 5 minutes I was switched to comcast.
Then I phoned WOW and canceled my service.

I've had my own modem for 3 years now, so saved paying nearly $400 so far :)
 
Comcast customer here as well with my own modem plugged into my UPS and it keep on 24/7. I've found modems usually last about five years before needing replaced. I would suggest locating them somewhere so they get some ventilation. To me renting a modem is throwing away money. Installing them is a no brainer, hook up and just call in the MAC number to your provider and you're in business.
 
Comcast customer here as well with my own modem plugged into my UPS and it keep on 24/7. I've found modems usually last about five years before needing replaced. I would suggest locating them somewhere so they get some ventilation. To me renting a modem is throwing away money. Installing them is a no brainer, hook up and just call in the MAC number to your provider and you're in business.

As a side note Icome from the days of 2400 baud modems, cackle, cackle, screech, screech.
 
Comcast has a website that shows you their approved modems you can buy, based on your location and subscription speed. Options on the left side of screen to help you pick the right one. I'm an Arris fan myself and have owned my own modem for past 10 years of Comcast service. Good luck.

mydeviceinfo.comcast.net
After signing in, and a click or two, I found my info:
ARRIS SB6183
Model number: SB6183
Shop for XFINITY-approved equipment
Model Specifications
This device is compatible with your service download speed of 60 Mbps.
Device Type
CableModem
Wired Download Speed
Up to 373 Mbps
Voice/Telephone enabled
No
WiFi enabled
No
DOCSIS Channels
16 down × 4 up
DOCSIS Version
DOCSIS 3.0
IPv6
Yes
There are newer models, but I'll wait til it breaks.
 
As a side note Icome from the days of 2400 baud modems, cackle, cackle, screech, screech.
I come from the days of 1200 baud, and remember people in our computer group who only had 300 baud. Add lots of wait time.
Equipment was so expensive, and you really could not afford to throw a device away, and buy another.
 
Hmmmm...they have the wrong modem in my Comcast account. It's a Motorola that's at least 4 or 5 years old. They have it as an Arris TG862G. I was planning on turning it in soon for a new one, but having the wrong one in their system is likely going to be a problem...
 
We don't use Comcast for the phone so my purchased cable modem to replace the Comcast one is:
https://smile.amazon.com/gp/product/B00MA5U1FW/ref=od_aui_detailpages00?ie=UTF8&psc=1

This Arris modem has been running trouble free since September 2017.




I might have to look into one of the other VOIP providers people talk about here... just a bit lazy on this.... I like to have the tried and true and be able to call someone when things are not working.... I can figure out a good number of things but if I get stumped I would rather have someone else do it...


I also have to consider the nagging that I would get from DW if something is NOT working... she is very hard headed at times and carry on forever about something.... I mean get me mad as heck nagging...
 
Back
Top Bottom