New 400 Mbps plan, phone transferred from modem to cell

@flatlander3​ 

I live in the Connecticut. The approved and recommended Docsis 3.1 modems are Arris S33, SB8200, and Motorola MB8600.  Netgear is priced much higher so I have ruled it out.  I like your comment about Docsis 3.0 modems being near their end of life.  My current modem firmware has not been updated since 2020.

The coax, splitter and swaged fittings were all installed by Comcast in ~2012.  The coax is solid copper core, 18? gauge series 6.  The coax goes from the house connection shown below to a four way splitter (picture). One coax goes from the splitter directly to the modem with no breaks.  Another goes to the living room and is not used.   I took these pictures in case this needs to escalate.   Thanks for your help again.

@flatlander3​ I am glad I took a photograph of the splitter.  You have identified quite a few issues.  I was told that the splitter was needed to reduce the levels, but I see 0.7 dBs on the splitter and I now question that explanation.

I put a ceiling in the basement so the coax is mostly buried.  I will replace the splitter with a union and look at the levels.  I am not in a hurry to do any of this because I do not have any problems with the current speed.  I think the only issue is I sometimes must resent web pages to update, but that could be anything.  Are the splitter coax connections tamper proof or will the coax terminations simply unscrew?

Thanks again for your rapid responses.  You have answers multiple questions I have had.  I get the cell phone tomorrow so the phone number will be transferred off the modem.  I assume the modem will be re-provisioned when the phone number is moved.

@goldfreaz​ Those connection are NOT tamper proof.  They'll just unscrew like any other coax connector.  Work from whichever side is easier.

** Edit:  For the Cell -- Well, I don't know how the phone number part works.  I never used a cable/SIP VoIP phone if you were talking about doing that, so I don't know if that cable phone number transfers to a cell carrier, or if it's State-by-State based, or what the deal is.  Local law may apply so it can or HAS to be able to.  If you were talking about porting from a cell carrier to a different cell carrier -- well of course, that works fine.  Usually no delay on that too, or it happens within an hour or so when you activate your brand new phone with your old number.

The modem, it's just the modem and does internet so that won't care one way or another.  If your previous plan was cable VoIP/Sip phone, the number just stop working on the next billing cycle, but the internet part still works.

@flatlander3​ Thanks for catching that.  I thought it was 0.7 not 7.0 dBs!

@flatlander3​ I found the attenuator on amazon.  I assume the polarity is correct if I screw it on the modem.  I will also buy a union to replace the splitter.

@goldfreaz​ Yep.  Only one way it goes in :)  I had to do that at one of my places too after a drunken neighbor took out the cable box and they "fixed the cable".

@flatlander3​ So Comcast turn off the landline Saturday morning but did not activate the mobile until Monday morning.  My wife was not happy which means hell for me. I installed the attenuator also this morning and it works exactly like you predicted.  The new readings are below.  I am assuming the downstream levels are good on the high side?

 

@goldfreaz​ Yeah.  Upstream has plenty of wiggle room, downstream has a bit to move too.  Usually only varies by 1-2 dB at the most anyway during the day.  Sometimes not that much at all.  

Let it ride for a week and see how it works out.