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CM500V vs CM1150V for 300Mbps or 600Mbps service?

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Contributor

CM500V vs CM1150V for 300Mbps or 600Mbps service?

I'm currently on the 75Mbps service but will be upgrading to 300Mbps or 600Mbps service.  I am wondering if the CM500V or CM1150V would be better for this. Is there any advantage of the CM1150V if I have the 300Mbps or 600 Mbps service? 

 

The CM500V is running about $100 and the CM1150V is about $240. I don't mind paying more if there is some advantage at those speeds. Does having 32 instaed of 16 downstream channels matter at those speeds? Is there some other advantage to the CM1150V even at those speeds?

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Diamond Problem Solver

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

You’re kind of handcuffing you’re self to certain speeds by picking the 500. What if you wanted to go even higher? Are you choosing the V because you also have phone service? In the end it’s your money but I’d go the 1150

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Expert

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

The CM500 can't do the 600 Mbps speed;

 

https://www.xfinity.com/support/devices#details



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Contributor

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

Yes I have interne&tvoice (because my wife insists on having a landline) but no TV.

 

Maybe with speed continually creeping up, the CM1150V would be a better choice. However, models keep improving and getting cheaper so if I only pay $100 for the CM500V today, there might be an even better DOCSIS 3.1 32x8 out in a year or two.

 

However, if I could put my finger on some nifty features on the CM1150V I could justify getrting it now! Diagnostics, event logging, error reporting, ...? 

 

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Contributor

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

Yeah, that's what Xfinity says (373Mbps max), but Netgear says 680, so which one is correct? 

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Expert

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

Comcast dictates the top speed capability. It doesn't matter what the manufacturer claims.



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Contributor

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

"Comcast dictates the top speed capability. It doesn't matter what the manufacturer claims."

 

Ah, that helps. 

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Contributor

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

 

What does this mean (for the CM1150V):

"Backward compatible 32x8 channel bonding in DOCSIS® 3.0 mode"

 

And, for this:

"32 downstream and 8 upstream channels with 2x2 OFDM"

When you're running 300Mbps service, does having 32x8 rather than 16x4 matter? 

What is 2x2 OFDM?

 

 

 

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Expert

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?


@garya505 wrote:

 

What does this mean (for the CM1150V):

"Backward compatible 32x8 channel bonding in DOCSIS® 3.0 mode"

 

It means that the modem supports both the DOCSIS 3.0 and the DOCSIS 3.1 services.

 

And, for this:

"32 downstream and 8 upstream channels with 2x2 OFDM"

When you're running 300Mbps service, does having 32x8 rather than16x4 matter? 

 

Although it is not necessary for 300 Mbps speed, more channels will always provide greater reliability. Think of it as having a 6 lane highway rather than a 2 lane highway at rush hour.

 

What is 2x2 OFDM?

 

That would be the DOCSIS 3.1 downstream channel with which Comcast provides the gigabit speed tier.


 



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Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

If you're not in a rush, the 1150V is periodically offered by Amazon at $199.  From a future-proofing perspective, I think it's worth the premium.

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Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

 

DOCSIS 3.1 is only used on the gigabit plans, right?  The 300Mbps and 600Mbps use DOCSIS 3.0?

 

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Expert

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

Correct.



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Contributor

Re: CM500V vs CM1150V for 300Mbps or 600Mbps service?

 

So, I plan to upgrade to the 300Mbps service (with voice). Here are the choices:

Arris SBV2402 ($100)

Netgear CM500V ($100)

 

For some degree of "future proofing" I could get:

Arris T25 ($200)

Netgear CM1150V ($250)

 

I guess I could wait until the CM1150V goes on sale but I'd like to upgrade ASAP. I suspect that putting a DOCSIS 3.1 on a 300Mbps service is a waste of money. Bu the time I need to upgrade to gigbit service the CM1150V price will be lower, and there will likely be more D3.1 products available as well.  I'd like to ditch the Xfinity voice to give me an easier modem choice but they don't have any decent internet-only prices at the moment. We don't want Xfinity TV so their Triple Play deals are not of interest to us either.   

 

 

 

 

 

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Is Xfinity 600Mbps on DOCSIS 3.1?

 

Yes I know DOCSIS 3.1 is for gigabit speeds, but what I'm asking is, if you have a DOCSIS 3.1 modem and Xfinity 600Mbps, will it be using DOCSIS 3.1 or 3.0 ?

 

 

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Expert

Re: Is Xfinity 600Mbps on DOCSIS 3.1?

The 3.0 / QAM256 multiple bonded downstream channels.



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Re: Is Xfinity 600Mbps on DOCSIS 3.1?

 

OK, so I got the CM500V.  The outages continue. The last two days I had my son log the outages to compare with the modem event log. They are the same, everytime there is an outage, the modem has logged an error. This happens aout 15 times per day, but only between about 9AM and 5PM, Monday through Friday.  

 

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Contributor

Re: Is Xfinity 600Mbps on DOCSIS 3.1?

Here are my power levels. The modem is a CM500V. Does the upstream look too low?

CableConnection.JPG

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Expert

Re: Is Xfinity 600Mbps on DOCSIS 3.1?

Can't see your pic. Since you are a new poster, it needs to be approved by a Forum Admin. That could take some time. In the interim, you could try hosting it at one of those free third-party pic hosting sites like Imgur or Photobucket and post the link to it here.



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Re: Is Xfinity 600Mbps on DOCSIS 3.1?

OK, try this.  Do my upstream power levels look too low?

BTW, I just restarted it and all the upstreams came up at 33.5.

https://imgur.com/a/RSUZcAz 

 

 

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Expert

Re: Is Xfinity 600Mbps on DOCSIS 3.1?

No.



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Re: Is Xfinity 600Mbps on DOCSIS 3.1?

 

I thought the minimum recommended with 4 locked channels was +35dBmV (range +35 to +49).

 

Everyday between about 9AM and 5PM I get outages. The last 2 days it was about 15 outages each day. Most of them are very short, 1 to 5 minutes. A few were longer, like 10 to 20 minutes, but no longer. The modem event logs are full of T3 and T4 errors with timestamps that correspond to the times we logged for the outages. Like this:

https://imgur.com/a/dtuiMJm 

 

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Expert

Re: Is Xfinity 600Mbps on DOCSIS 3.1?

If it is lower than 35 it just means that the upstream / return path has a very good and clean connection, so the CMTS hears the modem very well. Too high would be a problem, not low.

 

Also, take in to account that the measuring mechanisms of modems are not an exact science so the accuracy of any readings can be off by around 3 to 4 dB. You've got something else going on other than the upstream power level.

 

Your problem sounds like it is being caused by a traffic congestion / network capacity issue due to everyone now being at home and online. 



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