Upstream congestion - business service
 

I have had excellent performance on the 50 Mb/s business cable service with fixed IP subnet.

Speed tests usually run at around 48 Mb/s with very low jitter - 1-4 ms usually.

Last Friday there was a problem that caused the business Superhub to go offline - diagnosed as noise in the area , which cleared spontaneously within 30 mins.

Prior to this problem my upstream was locked onto Channel 2. Since the superhub reset on Friday it has gone to Channel 5 and performance is poor- around 6 Mb/s right now downstream.

I have just spoken to business faults. The engineer checked the port I am on - NMAL Cable 8/0/1 apparently. He said it was showing sustained 100% utilisation and has now logged it with the network team.

I asked if he could push me back onto Channel 2, but he said no he couldn't.

However I thought the idea was that if more than one upstream was available in an area then the Superhub would select the one with the lightest utilisation when it booted up? I have tried resetiing it multiple times but always it comes up on Ch 5 the congested one.

I might have misunderstood how this works though.... can anyone advise?
Perhaps it locks to the one with the lowest number of other users -which may not be the lightest loaded one of course.

Re: Upstream congestion - business service
 

They don't provide a tool (they should really because i know for this reason are many complain at VM forums) where we can change the channels to less congested

Had this issue my self many times because almost central London the network is almost congested all the times
With older firmwares it was easy after 1-3 resets will change channel
After R36 firmware (i don't have the business SH but i think is the same for all) it will not change channels easy

I manage to force the SH to change channel after about 30-40 resets ...so keep trying if you have enough time and good luck

Is something simple and they don't give us a tool or option in the SH to sort it by our selfs

Re: Upstream congestion - business service
 

Unfortunately the Superhub doesn't get to do any selecting, there's some brief communication from the network side which instructs it which channel(s) to use.

The network chooses which channel to assign client modems to based on some magic secret sauce algorithm that we know little to nothing about.

Re: Upstream congestion - business service
 

They have moved me to a different upstream today - which I see reflected in a different Channel number- moved to 2 from 5. Performance seems better now...

Re: Upstream congestion - business service
 

Thanks for update...is nice to know they can do it after requested

Re: Upstream congestion - business service
 

Sssh…..some know but don't tell anybody else:
Cisco Magic Spell Book

Re: Upstream congestion - business service
 

Sssh! VM don't use Cisco equipment everywhere

Re: Upstream congestion - business service
 

Well some updates on my upstream congestion problem. Having had to escalate to a customer complaints manager for help here I have now been told that my problem is indeed upstream congestion, that designs are underway to increase capacity on the New Malden node. However due to space restrictions they have to carry out building work in order to accommodate more racks of equipment. Estimate date is mid November worse case.

I do remember someone saying that the New Malden node is actually in one of their office buildings so maybe it's just moving internal walls to expand an equipment room as opposed to extending the building itself!

The strange thing is - on the 50/5 business service, I have just done a speed test - getting around 12 MB/s down and 5.3 Mb/s up.

Doesn't sound like upstream congestion to me? However when talking to them about performance they always look at upstream never downstream. Any ideas why?

I still have just 4 downstreams. Given that business services only go up to 50 Mb/s down will there ever be more than 4 downstreams for the business service? Or do all users get more when they are available in the area?

Re: Upstream congestion - business service
 

The experts should answer to you soon but the little i know it can be upstream congestion because VM confirmed at their forums in the past for similar problem i had

Upstream use QAM 16 and is only in use one channel at the moment so seems most of the cases is due to upstream

Look my graph how UPSTREAM congestion changed after reset SH and changed upstream channel from 358000 mhz to 45.000 mhz
https://www.cableforum.co.uk/images/...2012/08/82.jpg

Downstream channels and hoping upstream sometime later when will add more will be for everyone

EDIT
Of course if your area has too many users can cause and over subscribe congestion as well due to heavy downloads

Re: Upstream congestion - business service
 

I understand what you are saying, but since I am getting the maximum of just over 5 Mb/s upstream but only 12 Mb/s downstream (on a 50 Mb/s service) how can this be upstream congestionwhen I get full throughput on uploads.

Re: Upstream congestion - business service
 

It can be...when i find out after around 4-5 pm(long time ago that upstream congestion) my speed that time from 100mb, tested was down to 50-60mb

Re: Upstream congestion - business service
 

Yes I understand why upstream congestion can cause downstream performance issues. but since I am getting the full 5 Mb/s upstream it doesn't seem congested....

Re: Upstream congestion - business service
 

What you didn't tell us is whether or not your downstream channels changed as well. When the upstream goes from 1 or 2 to 5, it means they've turned on the upgraded upstream. So if the "upgraded" downstream is no as well, you've ended up on a congested set of downstream channels. In other words, a careless (that's being kind) resegmenation.

Does that fit?

Re: Upstream congestion - business service
 

Hi Sephiroth
If you mean for me .... then downstream channels stayed same locked at 29900 mhz (out of 5) and are still same up to date
Only upstream changed and you see the graph how congestion change

The only Upsteam channels since march (i am with VM) are...ch id 5>35800 and ch id 4>45800 mhz (at least these are the only appearing to me and the SH can log into them) and are the same when i was with XL 30mb(when first joined)...now i am with 100mb are still same upstream channels, always them 2 till now
Don't look to me there is any upgrade to Upsteam yet (only downstream from 4 to 5 channels)

Re: Upstream congestion - business service
 

for me just the upstream changed. the 4 downstream channels have never changed....
I understood there to be 4 upstreams too for this area and they just moved me to a different one, but the downstreams stayed the same.

Re: Upstream congestion - business service
 

They'll have resegmented, possibly. It's the only explanation. You went from 4 DS to 5 and moved upstream into an upgraded range. It just strikes me that they haven't taken network segment loads into accouint when they stuck several localities onto a particular segment.

That would explain the symptoms you describe.

Re: Upstream congestion - business service
 

In my case - just moved to a different upstream, and getting 5 Mb/s upload but only 8 Mb/s download right now on a 50 Mb/s business service

Re: Upstream congestion - business service
 

Tried a UDP speedtest lately?

Re: Upstream congestion - business service
 

Not sure I have - is there one you can recommend?

Re: Upstream congestion - business service
 

Re: Upstream congestion - business service
 

Thanks - that one says unable to test

Re: Upstream congestion - business service
 

Impressive :)

Re: Upstream congestion - business service
 

my experience of upstream congestion on VM is that at first it will affect jitter, then after download speeds, and then only after that upload speeds.

In short people uploading data appear to get priority over acks and small packets. If I was running VMs network I would swap it round so uploading data takes a hit to maintain ack's and small packet performance.

As for the modem choosing the channel, that seems open for debate.

the vmng300 (my vmng300 since seph disagrees with me) only seems to change upstream when its favoured one is down, whilst my superhub on older firmware will change with power cycling although not easily but possible. So the R36 behaviour change could well be making it like the vmng300 on channel selection?

Re: Upstream congestion - business service
 

That makes sense. I was surrpised to get the full 5 Mb/s up but 10% of what I expect down.

VM Business were able to force the Superhub onto a different upstream, but that is as congested it seems as the previous one.

Here is my Thinkbroadband graph - looks like classic congestion :-

http://www.thinkbroadband.com/ping/s...23-08-2012.png


The business superhub runs different firmware and is on 5.5.2R04T15-BU

Re: Upstream congestion - business service
 

Seems to make anonsense of the QoS settings I though business users benefitted from. Is that part of the contract or have they moved away from that too?

Re: Upstream congestion - business service
 

It seems congestion affects everyone...
This is bad...from 7pm to 11:30 is terible
Post this to VM forums and mention you have business...ask to change the upstream to better one even if they did all ready
Ask them if they going to do any fix for your congestion at your area or at least call them again
Hopefully they will do something about it

Re: Upstream congestion - business service
 

Normally if you post on the VM forums and mention you have business the only answer you get is that they only deal with residential :rolleyes: Business does have a 24/7 faults support line though it does tend to be only upto 2nd line outside of business hours.. No idea if that's changed since I left VMbusiness about March this year

Re: Upstream congestion - business service
 

Given that I have been told congestion relief needs more equipment at the node that requires building work to take place I am surprised that they haven't just enabled more upstream & downstream channels.

This area is still served by 4 d/s channels. I woudl have thought a quick way to provide congestion relief would be to provide more channels.

I assume this is enabled at the headend logically on the CMTS as opposed to more equipment?

Re: Upstream congestion - business service
 

"Never ascribe to malice that which is adequately explained by incompetence"

In other words, it might not be deliberate, but a side-effect of DOCSIS 3 grant behaviour, which VM have yet to deal with...

Re: Upstream congestion - business service
 

didnt say was deliberate.

Of course why havent they dealt with it? have they accidently not dealt with it?