US Cable Support > Cox HSI > [LA] Worth upgrading Moto SB5101 (DOCSIS 2) to SB6121 (DOCSIS 3)

[LA] Worth upgrading Moto SB5101 (DOCSIS 2) to SB6121 (DOCSIS 3)

Re: [LA] Worth upgrading Moto SB5101 (DOCSIS 2) to SB6121 (DOCSI

reply to mnkyboy
If you're going to upgrade your modem to DOCSIS 3.0 you might as well consider one of the 8 channel models for that matter. There's no price difference plus in some markets we've already rolled out speeds that exceed that the SB612x can handle.

I purchased a SB6121 the other day to test and see if I get any speed improvement. I've done about 20 speedtest since, and my speeds are a consistent 20Mbps +/- .5Mbps. With the SB5101, my speeds fluctuated from 5Mbps to 25Mbps. Why cant the 5101 give consistent speed, is it because of the multi channels that 6121 has?

It's not because of the multichannel directly, but having multichannel alleviates congestion that occurs when download from just one channel. I had the same issues with an old ARRIS EMTA I had (Docsis 2). I got a Cisco 8x4, and even though at the time my area was only bonding three downstream channels, it made the difference. I now have full 8x4 bonding and the consistency is the most noticeable improvement.

reply to mnkyboy
There is more available bandwidth when you bond more channels, so if you just have one downstream there is more chance of slowdowns due to over utilization. Same on the upstream, I would have bought a modem that can bond 4x8 instead of 4x4.

So Cox supports the new SB6141? Would it be worthwhile since I only have the Preferred plan? I might bring this one back and buy the 6141 on Ebay for $70. Someone posted in another thread the the Cox center on Airline Hwy sells modems and I could get a better deal there. I find it hard to believe they would be cheaper than online stores. I tried finding a phone# to call for pricing but its not listed anywhere.

Cox most certainly supports the SB6141. Just make sure to have a tech push a new firmware out, as the retail SB6141's have older firmware that may prevent it from bonding the full 8 channels in certain markets.

Having 8 channels made my downstream much more consistent, as for upstream, haven't noticed much yet. ( still on 3 chans )

reply to mnkyboy
You can get a cisco dpc3010 on ebay for about $30.

I only see used for $30.

reply to mnkyboy
I did exactly this and recommend the switch. Upload is much more stable--much less time spent jumping between channels (as now it's bonded to four channels). Since TCP requires uploaded ACKs, download performance also improved.

Peak speeds on download are unchanged, but upload speeds increased by an approximate factor of five.

I decided against 8 channel models as I could get the 6121 for about $60 on Amazon.com. No troubles in getting provision updated.

reply to mnkyboy

I ended up getting a SB6141 for $69. I've owned Motorola SB modems since Cox started offering internet, never had any issues. I need to return the SB6121 I bought from Walmart last week. During this time, I've done at least 30 speedtest various times of the day/week. Nearly every test I had a consistent 20Mbps, +/- .5 Mbps. D3 is definitely more consistent and reliable thand D2, at least for me...