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Motorola SB6121 and TWC 100 mbps

Hello I just got a notification letter from TWC told me that they have upgraded my speed to 100 mbps. All I have to do is unplug the modem for 10s and plug back on to upgrade the speed (old things)

 

I got a Motorola SB6121 (not leased TWC modem anymore) and it handled the Ultimate 50 mbps pretty well. Now when I test my speed it get up to 96-97 mbps, not fully 100. I know it may be something still under construction or the upgrade is not completed yet, but just want to make sure if the SB6121 can handle 100 mbps speed. AFAIK it can support up to 150 mbps. Correct me if I'm wrong.

 

Also TWC had given a new approved modem list. SB6121 doesn't have on that list for Ultimate 75-100, so again I'm a bit worry. I just bought this modem 3 months ago and I don't want to pay again for the SB6141. 

 

Anyone please help?

 

27 REPLIES
Expert

Re: Motorola SB6121 and TWC 100 mbps

You're not going to notice the difference between 50/5 and 100/5 on TWC's network much less the difference between 97-100 especially when going off the RR network.

 

There is an issue with using the 6121 on a congested neighborhoods node as it can only bond 4 downstream channels compared to the 6141 that can do 8 downstreams. It's more likely to have speed sags since it has half the channels.

You really need to look at tracert's to whatever url's you're planning to use it on to see where the congestion is and in the time frame you want. The only thing using a 6121 vs a 6141 will increase is the first hop ping time after your modem, That's the only link that's affected by the number of channels. If it's always low, there's going to be no difference between the 2 modems.  Any high ping times an that start after the first server link won't be helped by more channels.

 If you're getting lost packets, doesn't matter which modem or speed you use.

If you're routed thru Chicago, you're lucky to get 20/10 speed!

 

 It's all marketting and remember it's advertised as "speeds up to", As more people hog up bandwidth, everyone will suffer. Whatever you do, don't buy an all in one modem router wireless. And do use quality 1 gig rated cat 6 quality cables, not wireless.

 

The only issue I've seen with the 6141-6121 units is power resets thanks to faulty/overheated 12vdc  750ma supplies. Lots of them bad! Best replacement is a regulated 12vdc 1 to 3 amp center pin + supply.

Your log will show power loss resets for no good reason followed by the usual MIMO and TLV-11 startup messages.

 And yes, My 15/1 service improved a lot when I went from a docsis 2 single channel to a docsis 3.o  4 channel because the one channel on the 2.0 was plagued with interference from poor TWC design.

 

Rookie

Re: Motorola SB6121 and TWC 100 mbps

This modem, the one that you have now is only bonding 4 channels.  That could be why they dont approve it for the 75-100.  In theory it should do up to 180 down, however on thier  network it's a toss up.  Kinda like when I upgraded from docsis  2.0 on the same tier got 2 mbps faster.   The 6141 bonds with 8 channels which is currently the top standard,  Personally I would wait and go with the sb6183, that will bond with 16 channels, as maxx rolls out in the next year or two you are gonna need that over the 8.  

Rookie

Re: Motorola SB6121 and TWC 100 mbps

Msraye i agree with the all in one combos, however the new AC routers on the dual banded 5ghz is almost like running a cord.
Expert

Re: Motorola SB6121 and TWC 100 mbps

yes, but most people don't realize for thoseAC's to work at 200-300 they need current AC  wireless boards in their portable devices. and not live in an appartment building neighborhood, lol.

 

I believe the 16 down channel modems also have 12 channel up bonding available However that requires the local cable system to vacate ntsc cable channels 2-6 and replace every pole amp and filter between the head end and your home.

Most systems have already vacated channels in the 7-95 analog range to get 8 bonded downstream channels.

 

 

Helper

Re: Motorola SB6121 and TWC 100 mbps

96 97 sounds rather good, I would watch and wait,/. I would leave it be unless I see degradataion.

Browser

Re: Motorola SB6121 and TWC 100 mbps

Thanks, I'll keep my 6121 and see if anything happen. 

 

SB6183 is a beast but I don't like it's price. Too much for just a 100 mbps network (maybe less). TWC will need to improved their new max speed until it got stable. My speed package still show 50 mbps on TWC.

Observer

Re: Motorola SB6121 and TWC 100 mbps

Mine is all of a sudden not breaking 55!!!! Been always getting 100-112 mb!
Highlighted
Participant

Re: Motorola SB6121 and TWC 100 mbps

Double check your area supports 8 bonded channels - most still only support 4.
Participant

Re: Motorola SB6121 and TWC 100 mbps

Ok So Here in Los Angeles I had the same issue. I was paying for 50/5 then was upgraded and on Thursday night I noticed the slower speeds. I kept calling and they said since I was paying a discounted price in october I could not get the Free upgrade to 100/5. 

 

I read all the forms and upgrade my router from SB6121 to SB6141. They had to provision my modem and it kept rebooting and rebooting every 2-5 min for 2 hours. I disconnected it over night and plugged it in the morning and all working fine. I am back to 100/5. 

 

I do believe it has to do with the 8 Channel bond. the SB6121 only has 4 bonded channels. The SB6141 has 8. Last night when it was rebooting and rebooting over and over again it only was using 6 channels. I guess I just had to wait for my mac address to propagate or something in their system over night. Cause now its working great. 

 

I am getting 112mbps down and 6.1mbps up.