50Mbit Service Upstream Discussion - Page 8

Simcut · 24-01-2009, 23:29

Bugger, wonder when they are rolling out the 50mb in my area, mind you it doesnt seem worth it right now....their networks dont see mgood enough to handle 20mbit let alone 50! :/

broadbandking · 25-01-2009, 07:06

Ok this has been said many time before and I am going to say it again the new 50Mb is using DOCSIS 3.0 which in effect has seperate bandwidth to the DOCSIS 1.0 part of the network so VM can handle 50Mb, there are many reasons why you get a slow connection, mostley oversubed UBR but people need to read up on DOCSIS before they start saying that VM cant offer 50Mb.

RyanB · 25-01-2009, 08:28

Quote:

Originally Posted by Broadbandings

Indeed, we've got to get it together now

Anyway to avoid this all getting a bit hectic and a 'your provider' Vs VM

I completely agree but the competition is getting a bit hotter for VM vs [insert ADSL provider here]

I would love to have my upstream to be at least 10% of my downstream on VM

Ignitionnet · 25-01-2009, 08:44

Quote:

Originally Posted by RyanB

I completely agree but the competition is getting a bit hotter for VM vs [insert ADSL provider here]

I would love to have my upstream to be at least 10% of my downstream on VM

I would very much agree with you on this one, and there's no reason beyond a lack of interest in providing it that it isn't.

I really wish I could give a 5 minute explanation of why that's nice and easy to soak in but it's not the easiest thing to explain.

Please see the attachment for the upstream channels that are available to cable operators. These are single channels, no bonding involved. Comcast are using the one on the far right to deliver 10Mbps upstream on their 50Mbit product. Virgin have been using 2nd from left and 4th from left so far on their DOCSIS 3 deployment, and have been having issues with SNR in some areas with those.

Turkey Machine · 25-01-2009, 15:16

Quote:

Originally Posted by Broadbandings

I would very much agree with you on this one, and there's no reason beyond a lack of interest in providing it that it isn't.

I really wish I could give a 5 minute explanation of why that's nice and easy to soak in but it's not the easiest thing to explain.

Please see the attachment for the upstream channels that are available to cable operators. These are single channels, no bonding involved. Comcast are using the one on the far right to deliver 10Mbps upstream on their 50Mbit product. Virgin have been using 2nd from left and 4th from left so far on their DOCSIS 3 deployment, and have been having issues with SNR in some areas with those.

All the new modems issued by Virgin on all their tariffs are at least DOCSIS 2.0 capable. Why the hell haven't they enabled them like that? Moreover, yes they're DOCSIS 1.0/1.1 backwards-compatible, but even a small increment to DOCSIS 1.1 would yield a 20% increase in available bandwidth according to that graph! How trivial is it to implement such a thing on Virgin's end? If a Virgin employee can answer me that question directly, I'll be very happy to know.

I hate the fact they tout it as "the mother of all broadband", when other ADSL providers spank them in* the download speed stakes, reliability, and upload speed stakes.

*for some customers.

RubberyDuck · 25-01-2009, 15:19

Probably been answered elsewhere on this site, but how do they get away with stating Fibre Optic, when it is coax.

BT and every other ISP for that matter has some fibre somewhere in their circuit. Perhaps they should all mention it.

Ignitionnet · 25-01-2009, 15:20

Areas still running the 2nd from left DOCSIS 1.0 are doing so because either:

A) There's no need to move then to 16QAM as the current bandwidth is enough or
B) The network in that area is too noisy - as you move across the range the trend is that you generally need better quality and better maintained access network.

---------- Post added at 16:20 ---------- Previous post was at 16:19 ----------

Quote:

Originally Posted by RubberyDuck

Probably been answered elsewhere on this site, but how do they get away with stating Fibre Optic, when it is coax.

Because the Advertising Standards Authority say they can.

RubberyDuck · 25-01-2009, 15:23

Does somewhat distort the truth though, the ASA should not really allow that, but obviously do.

Ignitionnet · 25-01-2009, 15:58

Quote:

Originally Posted by RubberyDuck

Does somewhat distort the truth though, the ASA should not really allow that, but obviously do.

Any service that uses fibre optics for any part of the 'last mile' link can be described as fibre optic broadband.

Fibre To The Cabinet that BT are trialling on a larger scale later this year will be called 'fibre optic' even though it comes in via a telephone line!

broadbandbug · 25-01-2009, 16:20

Quote:

Originally Posted by Turkey Machine

All the new modems issued by Virgin on all their tariffs are at least DOCSIS 2.0 capable. Why the hell haven't they enabled them like that? Moreover, yes they're DOCSIS 1.0/1.1 backwards-compatible, but even a small increment to DOCSIS 1.1 would yield a 20% increase in available bandwidth according to that graph! How trivial is it to implement such a thing on Virgin's end? If a Virgin employee can answer me that question directly, I'll be very happy to know.

I hate the fact they tout it as "the mother of all broadband", when other ADSL providers spank them in* the download speed stakes, reliability, and upload speed stakes.

*for some customers.

There is currently an issue with some of the VM Set Top Boxes that is stopping them operating D2.0, that will be fixed over the next few weeks. The other reason is that QAM32 or QAM64 require vastly 'cleaner networks' than VM are currently able to support.. As is being discussed here they are struggling to support QAM16 in some areas.

Turkey Machine · 25-01-2009, 16:54

Quote:

Originally Posted by broadbandbug

There is currently an issue with some of the VM Set Top Boxes that is stopping them operating D2.0, that will be fixed over the next few weeks. The other reason is that QAM32 or QAM64 require vastly 'cleaner networks' than VM are currently able to support.. As is being discussed here they are struggling to support QAM16 in some areas.

To just expand on that, my modem is currently connected downstream to QAM256, the upstream is on QPSK. Judging by what I've read so far in this thread, that should more than qualify it for DOCSIS 2.0, heck DOCSIS 3 if the right modem's about.

broadbandbug · 25-01-2009, 17:41

Quote:

Originally Posted by Turkey Machine

To just expand on that, my modem is currently connected downstream to QAM256, the upstream is on QPSK. Judging by what I've read so far in this thread, that should more than qualify it for DOCSIS 2.0, heck DOCSIS 3 if the right modem's about.

The fact that your DS is QAM256 is nothing special, in fact that is defacto across the whole of VM with exception being the Bromley Platform that has a legacy STB that will not function at QAM256 and the DWDM areas of Langley.

DoCSIS 1.0 upstreams will support QPSK and QAM16, so your area either doesn't need the bandwidth to justify QAM16 or the area is too noisy to support it.

I have absolutely no idea why you think this would 'more than qualify it for DoCSIS 2.0'?

DoCSIS 2.0 brings in the ability to provide QAM32/64 in the upstream. However the network has to perform to specific noise characteristics to support it. With your area operating at QPSK, it is unlikely that in its current state it would support QAM16, let alone QAM32/64.

DoCSIS 3.0 is a totally different platform and the DS operate at EuroDoCSIS QAM256 and are channel bonded, so as you say a new modem.

For the upstream, it uses DoCSIS 2.0 technology at the moment anyway (no US channel bonding) so what I have said about D2.0 applies.

Turkey Machine · 25-01-2009, 18:47

Silly me thought that the higher the number on the end of QAM meant it had a higher bandwidth. I guess QAM256 would be equivalent to 256KHz then?

Ignitionnet · 25-01-2009, 19:53

Quote:

Originally Posted by Turkey Machine

Silly me thought that the higher the number on the end of QAM meant it had a higher bandwidth. I guess QAM256 would be equivalent to 256KHz then?

256 point constellation Quadrature Amplitude Modulation.

Still doesn't mean anything for upstream performance what the downstream is doing.

There's even at least one area that's doing DOCSIS 3 on 64QAM downstream. The modulations do not count for anything on the DOCSIS version that's being run.

Have a quick look at the whole wonders of DOCSIS, many resources available on the web.

hokkers999 · 25-01-2009, 22:26

Quote:

Originally Posted by broadbandking

Ok this has been said many time before and I am going to say it again the new 50Mb is using DOCSIS 3.0 which in effect has seperate bandwidth to the DOCSIS 1.0 part of the network so VM can handle 50Mb, there are many reasons why you get a slow connection, mostley oversubed UBR but people need to read up on DOCSIS before they start saying that VM cant offer 50Mb.

No, if you read the other thread about this, specifically the pdf that was linked to, docsis 3.0 does not increase the aggregate bandwidth by a single byte.

---------- Post added at 23:26 ---------- Previous post was at 23:25 ----------

Quote:

Originally Posted by Broadbandings

Glad you're having a good experience.

It's supposed to be at 192.168.100.1 but I understand that a lot of people are seeing issues getting to it.

Though I saw on another thread somewhere, that you have about 5 mins after booting the modem to login to it, after that no go.