Hub 3 / Compal CH7465-LG (TG2492LG) and CGNV4 Latency Cause

[Datalink]

Good Day Ladies and Gentlemen,

Greetings from the other side of the pond, so to speak.  Over the last few weeks I've been perusing various user forums across North America and Europe for issues related to Intel Puma 6 modem latency.  Of those forums, your Hub 3 stands out as yet another Puma 6 based modem where users see continuous latency no matter what site is used or what online game is played. Considering all of the problems that are on the go, the following information should be of interest to all Hub 3, Compal CH7465-LG and Hitron CGNV4 modem users.  There is much more to post regarding this, so this is a start, to alert VM users as to the real cause of the latency and hopefully engage the VM engineering staff, via the forum staff, with Arris.  I am surprised to see that there has been no mention on this board of users from other ISPs who are suffering the exact same issues with their modems, so, this may come as a surprise to some, and possibly old news to others.

So, the short story ........

The Hub 3 / Compal CH7465-LG (TG2492LG) & Hiton CGNV4 modems are Intel Puma 6 / 6 Media Gateway (MG) based modems.  These modems exhibit high latency to the modem and high latency thru the modem.  The latency affects all IPV4 and IPV6 protocols, so it will be seen on every internet application and game.  The basic cause is the processing of the data packets thru a CPU software based process instead of thru the hardware processor / accelerator.  It appears that a higher priority task runs periodically, causing the packet processing to halt, and then resume.  This is observed as latency in applications and in ping tests to the modem and beyond.  For the last several weeks, Hitron, along with Intel and Rogers Communications in Canada have been addressing the latency issue within the Hitron CGNxxx series modems.  To date, only the IPV4 ICMP latency has been resolved.  Although this is only one protocol, it does show that a Puma 6MG modem is capable of using the hardware processor / accelerator with good results.  Currently Rogers is waiting for further firmware updates from Hitron which should include an expanded list of resolved protocol latency issues.  For Arris modems, "Netdog" an Arris engineer indicated last week that Arris was onboard to address the issue for the Arris SB6190 modem.  That should be considered as good news for any Arris modem (read Hub 3) user as Arris should be able to port those changes over to other Puma 6/6MG modems fairly quickly.  This is not a trivial exercise and will probably take several weeks to accomplish.  Note that there is no guarantee at this point that it is possible to shift all packet processing to the hardware processor / accelerator without suffering from any packet loss side effects.  Time will tell if all of the technical issues can be resolved with the current hardware included in the Puma 6/6MG chipset.  Last night, Netdog loaded beta firmware on selected test modems on the Comcast Communications network.  As this was only done last night, it's too soon to tell what this version resolves and if it was successful or not.  Netdog has contacts with staff at Comcast, Rogers, Charter and Cox Communications to fan out beta versions and modifications for testing.  I'd say its time to add Virgin Media and/or Liberty Global to that group as well.

Recent activity:

Approx three weeks ago a DSLReports user, xymox1 started a thread where he reported high latency to an Arris SB6190 and illustrated that with numerous MultiPing plots.  This is the same latency that I and other users with Rogers communications have been dealing with for months so it came as no surprise.  As well as reporting via that thread, xymox1 took it upon himself to email several staff members at Arris, Intel, Cablelabs and others.  The result of that campaign was Netdog's announcement, last week, that Arris was fully engaged at resolving the issue.  That has led to last nights release of beta firmware, although as I indicated its too early to determine what the beta firmware resolves, if anything.

The original thread that xymox1 started is here:

https://www.dslreports.com/forum/r31079834-ALL-SB6190-is-a-terrible-modem-Intel-Puma-6-MaxLinear-mis...

Yesterday, DSLReports issued a news story covering the thread:

https://www.dslreports.com/shownews/The-Arris-SB6190-Modem-Puma-6-Chipset-Have-Some-Major-Issues-138...

Today, Arris responded:

https://www.dslreports.com/shownews/Arris-Tells-us-Its-Working-With-Intel-on-SB6190-Puma6-Problems-1...

That response was also picked by Multichannel.com

http://www.multichannel.com/news/distribution/intel-arris-working-firmware-fix-sb6190-modem/409379

This is more news likely to appear in the next few days as additional tech and news staff pick up on this issue.

Hub 3 observations:

Like many others using a Puma 6/6MG modem, Hub 3 users are experiencing latency when they ping the modem, or ping a target outside of the home, game online or use low latency applications.  The common misconception is that this is Buffer Bloat. It's not. Its most likely a case of the packet processing stopping while the CPU processes a higher priority task.  The packet processing is done via the CPU no matter what mode the modem is operating in, modem mode or router mode and no matter what IPV4 or IPV6 protocol is used.  Normally, the latency is just that, latency.  The exception are UDP packets. In this case there is latency and packet loss.  The result of that is delayed and failed DNS lookups, and poor game performance for games that use UDP for player/server comms or player/player comms.

Can this be fixed?

So far, it appears that the answer is yes.  Rogers Communications issued beta firmware to a small group of test modems in October.  This version shifted the IPV4 ICMP processing from the CPU to the hardware processor / accelerator, resulting in greatly improved performance in ping latency.  At the present time we are waiting for the next version firmware which should shift other protocols over to the hardware processor / accelerator.  That can be seen in the following post:

http://communityforums.rogers.com/t5/forums/forumtopicpage/board-id/Getting_connected/message-id/369...

The details and results of last nights beta release to the Comcast group have yet to be seen.

At this point there is enough reading to keep most staff and users busy.  My intention is to post some of the history leading up to this point and instructions on how to detect the latency and packet loss.  This is not thru the use of a BQM.  I had hoped to post this all at once but events are moving much faster than I had thought they would.  For now this should suffice to get the ball rolling.

Below is a link to a post with a couple of HrPing plots from my 32 channel modem to the connected CMTS.  This shows the latency that is observed and reflects what others have posted in this forum using Pingplotter and HrPing.

https://www.dslreports.com/forum/r31106550-

HrPing is one of the freebie applications that can be used to monitor the latency to and thru the modem. 

Pingplots with Pingplotter which show the latency from my modem to the CMTS can be found in the first two to three rows of my online image library at Rogers Communications, located below.  They are essentially what the BQM would look like if you were able to zoom into the plot to the point where you could see the individual ping spikes.  Those ping spikes are common to Puma 6 and Puma 6MG modems.

http://communityforums.rogers.com/t5/media/gallerypage/user-id/829158

 [MOD EDIT: Subject heading changed to assist community]

[shanematthews]

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@RidingTheFlow wrote:

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shanematthews wrote: 

So, you want VM to postpone installing the ONLY hub they now supply? you do realise this means they would be unable to replace damaged hubs or install any new customers at all, you must also realise that this would never happen

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That's why I said it should've been done immediately after they started SH3 rollout (and issue was first reported). While they still had huge stock of SH2 left, it took months to run out.

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shanematthews wrote: 

Well there was a 50 page thread here which clarifies the issue, you're expecting VM to try and educate off-shore 1st line monkeys in what latency issues are and how they might impact people using a hub3 only, you can't even explain packet loss to some of those people, they don't have a clue about anything that isn't fixed by turning the hub off and on again, you're never going to train them in this and staff turnover makes that borderline impossible

Internal memos will have been sent, they won't have made any real difference as above

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Yes, I expect them not to use incompetent off-shorers for support and train their staff better if its an issue. Also, even incompetent staff you can instruct not to replace SH2 with SH3 if SH2 is not broken - you don't even need to explain to them, why its needed.

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shanematthews wrote: 

The hardware companies would have been notified, even if VM did make idle threats about changing provider, which is a different issue as we don't know the terms of their contract which may or may not contain allowances for issues taking months to resolve, even IF they wanted to change providers you're looking at numerous months of rounds of bidding, testing, trials then mass production and shipping of the new devices along with the additional training costs, the costs of replacing marketing images and leaflets along with the costs of trying to recall all hub3's still in engineers vans etc, its not a threat they would realistically be able to follow up on

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They would be if they had a will to fight for their customers. Which would cause the suppliers to actually spend more effort and issue would've fixed much sooner - if they'd realise there is actual threat of losing future business with such huge customer as VM. Though you right, I don't know terms of contract. Most likely supplier just suggested they cut price in third if VM agrees not to be "confrontational", and such lure of money savings was too much to pass.

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shanematthews wrote: 

You see them concealing, the rest of us see it as damage control, the issue was well known and even if a rep had made a post on her acknowledging the issue it wouldn't have changed anything and would have caused more harm than good, the puma6 issue doesn't affect all users and even those it does affect are affected in varying degrees, however nobody would read that part they would just read the hub3 was faulty and decide to go elsewhere, not really a sound business choice, my mother has a hub3 and it doesn't impact her internet use at all

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Well, you see I myself wasn't even aware that I must trawl the forum for potential issues with new modem, before I allowed engineer to replace my (perfectly fine) SH2 with "new improved" (as he said) SH3 and let my peak latency shoot through the roof. Everybody has own use case and I totally agree that majority of people wouldn't even mind - but Virgin should've just said so (and if person can't understand if its a problem, fine, then no problem). But people who would mind wouldn't be upset, and wouldn't later recommend their (similarly techy-adept and connected friends) to stay away, and won't inform the tech press about whole blunder. That is what I'd call "not really a sound business choice". 

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Yes it took months to run out, with the hub3 in active distribution, without the hub3's going out it would have run out a lot sooner and we would be long past getting new installs, but you already knew this

"Yes, I expect them not to use incompetent off-shorers for support and train their staff better if its an issue."

bwahahahahahaha, know any other good jokes? they use them because they are cheap and filter out most of the issues resolved by reboots, they aren't there for actual tech suppport, 1st line rarely is, try any company and you'll probably get through to india most of the time, cheap labour for solving the tasks that are covered by a script, in this case the hub3 isn't scriptable so we got a lack of support for it, pretty much end of on that, they sadly aren't going to spend the money needed to hire competent techs to man most of the lines, there are some and the UK based ones know what they are talking about 99% of the time

"They would be if they had a will to fight for their customers. Which would cause the suppliers to actually spend more effort and issue would've fixed much sooner - if they'd realise there is actual threat of losing future business with such huge customer as VM."

So, 2 issues, firstly, their will to fight for the customer has NOTHING to do with the time it takes to diagnose and fix an issue like this, people always seem to think it takes 5 minutes to diagnose complex code, even simple code can take ages to diagnose, and this is assuming there is even a simple fix, which this doesn't seem to be, the unit was designed to operate in a specific way, i mean if you think you could have fixed it faster then i suggest looking at the intel careers page to earn some serious cash, there is only so many resources you can put in to fixing an issue and adding more people to a team or throwing money at a project won't accelerate things, these things take time and thats something people need to understand before spouting rubbish off implying intel and VM just don't care enough to fix it, intel are also very painfully aware of what it feels like to lose contracts to other companies, they lose contracts to AMD and other companies all the time so they know there is always a threat of losing business, however, it won't be from VM it will be from the likes of netgear and arris, intel doesn't have a direct relationship to VM, they just happen to provide the modem used by 3rd party companies that make the stuff VM rebrands and ships out, VM don't actually make anything 😛

And we will just have to agree to disagree on the last part, companies do it all the time and i don't see any of the giants going bust over it

[wotusaw]

Saw this earlier so it looks like the 93V update is sorting the problem. However, this is probably old new news to all you Boffins.

I have learnt alot from all of you. Thanks tons.

http://www.dslreports.com/forum/r31340594-ALL-SB6190-and-CM700-latency-fix-firmware-ready-to-test~st...

Before all this started I thought 'modems' were akin to simple crystal radios. In other words very simple devices. Boy, was I wrong.

Happy to see the 'end' is almost in site and I will be able to hopefully kick arse on Titanfall 2 once more.

Missed kicking arse sooo much.

[Drewley]

That firmware update was released in April, and still nothing for us 😞

[Shelke]

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@Drewley wrote:
That firmware update was released in April, and still nothing for us 😞

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Well the problem chip was used in various kinds of cable router+modem combos. So I would imagine that it isn't a one for all patch and that all the varying models which made use of the chip would have to have the patch tailored into the firmware for the specific model/any custom firmware designed for use on that specific model.

+Add: Don't forget that the hub 3.0 is used by all of LGs cable ISPs, so that shared nature of the hub developmentally and process management wise adds further delays.

It's not like the Superhub 1 to Superhub 2 AC which are solely in VM's court.

[shanematthews]

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@Shelke wrote:

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@Drewley wrote:
That firmware update was released in April, and still nothing for us 😞

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Well the problem chip was used in various kinds of cable router+modem combos. So I would imagine that it isn't a one for all patch and that all the varying models which made use of the chip would have to have the patch tailored into the firmware for the specific model/any custom firmware designed for use on that specific model.

+Add: Don't forget that the hub 3.0 is used by all of LGs cable ISPs, so that shared nature of the hub developmentally and process management wise adds further delays.

It's not like the Superhub 1 to Superhub 2 AC which are solely in VM's court.

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No they aren't, both the hub 1 and 2 are rebranded netgear devices, VM doesn't make any of the equipment they provide its all modified 3rd party stuff

[Shelke]

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@shanematthews wrote:

No they aren't, both the hub 1 and 2 are rebranded netgear devices, VM doesn't make any of the equipment they provide its all modified 3rd party stuff

I know Netgear made them, they had more indepth involvement that can't be posted about, so it's not as simple as you say it is. What VM had with NG was for those models was unique and wasn't shared with other LG owned ISPs. So hopefully you don't mind having your correction corrected?

[Xymox]

Greetings from across the pond !!! Congratulations on your Register news story ! Good job...

I have just created a very basic web site that focuses on the Puma 6/7 issue.. Its collected everything in one place with easy to understand dialog..

Its a work in progress just done tonight..

Ive also put a forum and wiki there if anyone wants to use those.

i did the site so new people to the issue can get everything they need right away in a quick and concise form..

I also have a link to this thread on the main first page.

http://www.badmodems.com/

[Petelunn]

This has been going on far to long, Virgin just needs to swap out these crappy modems. Searching google I find all the below stories:

Netgear confirms: Intel's wobbly Puma 6 in fast broadband modems is super-easy to choke out
No fix ready yet for DoS-able home gateways

https://www.theregister.co.uk/2017/05/01/netgear_puma_6_modems_trivial_to_crash/

Intel's buggy Puma 6 chipset earns Arris a gigabit-modem lawsuit
Laggy silicon at heart of broadband boxes lands gateway maker in court

https://www.theregister.co.uk/2017/04/11/intel_puma_6_arris/

UPDATE Virgin Media Prep Firmware Fix for SuperHub 3 Latency and Packet Loss - THIS WAS MARCH

http://www.ispreview.co.uk/index.php/2017/03/virgin-media-prep-firmware-fix-superhub-3-latency-packe...

Cable modems with the Intel Puma 6 chipset LAG!!

https://linustechtips.com/main/topic/736823-cable-modems-with-the-intel-puma-6-chipset-lag/

The list goes on - and its been going on and Virgin has know about it for over 6 months with little will to fix it and they are still rolling out these known faulty modems to consumers. Its a shame we do not have a mechanism like a class action suite but I urge everyone to complain to ofcom here:

https://ofcomforms.secure.force.com/formentry/SitesFormCCTMonitoring

[Drewley]

@Xymox

Superb! Could you add the ofcom contact link the chap below you posted to the UK "what can I do" section? (https://ofcomforms.secure.force.com/formentry/SitesFormCCTMonitoring)

Thanks

[wotusaw]

Thanks a bunch 'XYMOX1'. 

I've put the link on my clansite, 'The BN Nitwitts on Enjin'. Ouch/Avit(clan leaders) and myself all have the Virgin HUB 3.

http://thenitwitts.enjin.com/forum/viewforum/5250475/m/28206608

I am extremely grateful to you for all your hard work.