dslreports logo
 
    All Forums Hot Topics Gallery
spc
uniqs
25
lilstone87
join:2009-04-09
Chesapeake, VA

lilstone87 to bryant313

Member

to bryant313

Re: [NV] 64QAM on the upstream in Las Vegas?

said by bryant313:

lost 64QAM again

hopefully all these improvements lead towards speed upgrades like Rhode Island saw

Well I can tell you for sure, the load balancing feature cox has used on the upstream, has been rather a disappointment. I was happy once upstream channel bonding went live here. If I remember correctly, when I was on a single upstream channel, and cox started using load balancing on the upstream. My modem would jump between different upstream channels, one would be 16QAM, and other 64QAM. Oddly though, if I was on a 16QAM channel, and started using upload bandwidth, the modem would switch to the 64QAM channel.
bryant313
join:2011-05-24
Las Vegas, NV

bryant313

Member

did you see any overall burst upload speed improvements?

what is the benefit of load balancing?
lilstone87
join:2009-04-09
Chesapeake, VA

lilstone87

Member

said by bryant313:

did you see any overall burst upload speed improvements?

what is the benefit of load balancing?

Well exactly what it sounds like, to help balance the load on all the available upstream channels. Sadly here, it had more of a negative effect more then anything. As for speed improvements, I am sure it kept people being able to max there upload speeds. But for me, it had my modem switching threw upstream channels a lot, when actively using upstream bandwidth.
bryant313
join:2011-05-24
Las Vegas, NV

bryant313

Member

yeah i hope that is not what it comes to i mean i still only have one upstream channel but it keeps going between 16QAM and 64QAM pretty much what you described

are they still load balancing your upstream channels?
lilstone87
join:2009-04-09
Chesapeake, VA

lilstone87

Member

said by bryant313:

yeah i hope that is not what it comes to i mean i still only have one upstream channel but it keeps going between 16QAM and 64QAM pretty much what you described

are they still load balancing your upstream channels?

No once upstream channel bonding is in place, load balancing on the upstream is no longer a factor. As you are connected to multiple channels, making it a useless feature to be used anymore.
bryant313
join:2011-05-24
Las Vegas, NV

bryant313

Member

okay

how long were you load balanced before you got upstream channel bonding?

CoxVegas
join:2011-07-25
Las Vegas, NV

1 edit

CoxVegas to bryant313

Member

to bryant313
As has been mentioned, it is a mostly automatic process designed to spread out the load between upstream channels.

There isn't any practical benefit* to 64QAM over 16QAM except for the channel using 64QAM having a higher total carrying capacity (by 50%) - it doesn't really matter for end-user performance as long as there is enough bandwidth available on whatever channel you settle on for your needs. The total carrying capacity in either scheme is more than your maximum provisioned upstream bandwidth.

Or, put it another way, say there are 3 channels, 2 at 64QAM and 1 at 16QAM. To simplify, we'll call it buckets of bandwidth, so we have 30, 30, and 20 (remember the 64QAM is 50% more than 16QAM). If we have 60 need, we could spread it 30, 30, and 0, but that would leave no room for burst, etc. A better spread is 23, 24, 13 (or so), leaving us 6-7 buckets available on each channel for burst or additional customers.

tldr; version: The people on 16QAM aren't getting inferior service just by being on a 16QAM channel.

* 64QAM is more vulnerable to poor line conditions. This is the main reason why all 3 channels aren't using 64QAM - it's gives modems a place for those cases where line quality doesn't allow 64QAM. Being on 16QAM doesn't necessarily mean you're in that case (very, very few people actually are) - it most likely means we're just trying to make use of the bandwidth that is there since there's not enough people that HAVE to use it.
bryant313
join:2011-05-24
Las Vegas, NV

bryant313

Member

once again thank you for the info

i wonder what parts of vegas already have upstream channel bonding?
bryant313

bryant313

Member

just ran a speed test and i am bursting up too 13mbps up on one single upstream channel with 64QAM enabled but it drops right back to 2mbps almost instantly

and on the cox speed test i am bursting up to 20mbps up on one single 64QAM enabled channel

CoxVegas
join:2011-07-25
Las Vegas, NV

CoxVegas to bryant313

Member

to bryant313
Regarding what parts of Vegas, I can't disclose that - partly because it's an ongoing operational issue and partly because it's by node and the boundaries would be no sense at all - we have giant printed maps databases, and timelines to keep track of it all.

digiblur
Premium Member
join:2002-06-03
Louisiana

digiblur to CoxVegas

Premium Member

to CoxVegas
said by CoxVegas:

* 64QAM is more vulnerable to poor line conditions. This is the main reason why all 3 channels aren't using 64QAM - it's gives modems a place for those cases where line quality doesn't allow 64QAM. Being on 16QAM doesn't necessarily mean you're in that case (very, very few people actually are) - it most likely means we're just trying to make use of the bandwidth that is there since there's not enough people that HAVE to use it.

Thanks for that confirmation as I heard someone else say something was wrong if all the channels weren't 64QAM. I didn't think that was the case as I expected it was for exactly what you are talking about. I had a friend that had horrible cable modem signals due to splitters and such and it was only bonding 2 upstream. Once I got him in line with almost perfect signals he's now bonding 4 channels (2 at 16 and 2 at 64)