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]

[JohnE4U]

I think at this stage it is worth pointing out, I am NOT a gamer.  Despite this fact, my experience using the internet IS AFFECTED negatively by the latency issue.

I would also like to suggest to Shane, that despite the many things that VM do not have control over in respect to this issue, they do control how their product is advertised, and they do control how their customer support staff deal with customers contacting them that are affected by this issue.  In both cases Virgin chose not to acknowledge the known issue, rather, get their "valued" customer to sit in for half a day at a time to wait for the VM engineer to arrive; this, full in the knowledge that this is a pointless exercise!!!

VM have made many decisions here, none are with the customer in mind, all are about their bottom line.

For me, this is at least dishonest, at worst fraudulent (they still take my money for the service).

Fraud -> "wrongful or criminal deception intended to result in financial or personal gain"

[RidingTheFlow]

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@JohnE4U wrote:

 In both cases Virgin chose not to acknowledge the known issue, rather, get their "valued" customer to sit in for half a day at a time to wait for the VM engineer to arrive;

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I don't think they think of you of any kind of "valued" by any means, more of a "collateral". I spoke to retentions and was told quite clear "sorry nothing we can do" even after I made clear I will have to leave since I can't use such service.

It appears that they've already written off the costs of this whole mess.

[boltedenergy]

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@RidingTheFlow wrote:

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@JohnE4U wrote:

 In both cases Virgin chose not to acknowledge the known issue, rather, get their "valued" customer to sit in for half a day at a time to wait for the VM engineer to arrive;

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I don't think they think of you of any kind of "valued" by any means. I spoke to retentions and was told quite clear "sorry nothing we can do" even after I make clear I will have to leave since I can't use such service.

It appears that they've already written off the costs of this whole mess.

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If there were multiple players in the market and in more areas with 200+ speeds they would start to care very quickly about customer retention.

The problem is, the choice is usually between them or  one of the DSL based providers who are not even worth considering if you are in it for the speed.

But that ends up being a completely different discussion... 

[RidingTheFlow]

I told them they I will have to settle for lower speed, since such kind of latency spikes make it barely usable for anything real-time-sensitive. I don't download massive amounts of data every day.

They still don't care, as long as it not on their standard cheat sheet. "not my fault" - most universal excuse.

[rio_w]

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@RidingTheFlow wrote:

I told them they I will have to settle for lower speed, since such kind of latency spikes make it barely usable for anything real-time-sensitive. I don't download massive amounts of data every day.

They still don't care, as long as it not on their standard cheat sheet. "not my fault" - most universal excuse.

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Surely somewhere in their T&Cs there must be a clause that can be used to address this latency/faulty hardware issued to customers. I’m not a lawyer nor do I know much law when it comes to consumer rights being neglected by companies, but this surely is borderline illegal, our money is being taken for unsatisfactory provision of a service and what’s worse, we have to handover funds for a lengthy period of time with no compensation, no updates from Virgin Media and 6 months waiting without some sort of fix guaranteed or attempted. We have to get information about VIrgin Media from “theregister” and from across the pond which is strange as we are on Virgin Media’s forum where we should get direct support and feedback for any issues we encounter with their service or products provided. It’s time Virgin downsize their portfolio and concentrate on fewer business ventures, from what I’m hearing about the customer treatment lately from their airline it could do with some attention.

My final thoughts are we should be able to leave this service penalty free.

[shanematthews]

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@rio_w wrote:

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@RidingTheFlow wrote:

I told them they I will have to settle for lower speed, since such kind of latency spikes make it barely usable for anything real-time-sensitive. I don't download massive amounts of data every day.

They still don't care, as long as it not on their standard cheat sheet. "not my fault" - most universal excuse.

---

Surely somewhere in their T&Cs there must be a clause that can be used to address this latency/faulty hardware issued to customers. I’m not a lawyer nor do I know much law when it comes to consumer rights being neglected by companies, but this surely is borderline illegal, our money is being taken for unsatisfactory provision of a service and what’s worse, we have to handover funds for a lengthy period of time with no compensation, no updates from Virgin Media and 6 months waiting without some sort of fix guaranteed or attempted. We have to get information about VIrgin Media from “theregister” and from across the pond which is strange as we are on Virgin Media’s forum where we should get direct support and feedback for any issues we encounter with their service or products provided. It’s time Virgin downsize their portfolio and concentrate on fewer business ventures, from what I’m hearing about the customer treatment lately from their airline it could do with some attention.

My final thoughts are we should be able to leave this service penalty free.

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There is no clause in relation to latency, its impossible to predict, the same reason there isn't a guaranteed speed in your contract either, they have no control over these things, the service they sold you, regardless of if you had the gamer package or not, was for "up to" a certain speed tier, and aslong as you're getting that you're unlikely to have any kind of easy time changing provider, the price increase in november is likely to be your best bet unless you can get through to an extremely sympathetic advisor aware of the issue who is willing to have the early cancellation fees waived

Now on to the people who will nitpick about the "gamer" package, it was never advertised with any regards to latency and the only difference between it and the standard 200 was the removal of STM, that being said, the package itself wasn't the cause of the latency as i have the 200 gamer myself on a hub 2 (stock not AC) and it performs exactly the same as it always did in terms of latency and removes the STM as it said, the latency issue is purely down to the hub 3 and its less than ideal hardware so you're not even likely to be able to even attempt to get it dismissed as the package not being suitable for gamers, "fit for service" is also a grey area as no minimum level of service was specified on ANY of the tiers they offer, and as the hub 3 is the only residential hardware they actively stock you're stuck with that, from what i've heard the latency on the business grade equipment they offer isn't any better, and generally wouldn't be expected to be as its designed more for business use where latency isn't as important most of the time

You can try to go down the complaints route but by the time you get your complaint handled, then appealed, then forwarded on to the ombudsmen it will likely already be november and you'll be free to leave with the price increase, you could get lucky but technically speaking VM could fight you all the way and win if they really wanted so its probably just better to try and play "retentions roulette" 😛

[Xymox]

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@JohnE4U wrote:

Oh, and please share my Facebook post.  Let's start making some noise about this.  Virgin are happy for you to keep complaining within their forum, it keeps it contained.

Share, please.

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Shared on the Bad Modems FB page

 [MOD EDIT: Personal and private information has been removed from this post. Please do not post personal or private information in your public posts. Please review the Forum Guidelines]

[Xymox]

A lot of you guys will not be happy about what im going to say here...

As you know, im fighting the good fight and have put in a LOT of time on this and have a fairly good understanding of the issue.

shanematthews

Is right about pretty much everything he has said in the past 3 pages of posts.. I *CAN RELATE* that its not what you want to hear, however its the truth.

VM has been caught off guard by all this. In the whole history of cable internet nothing like this has happened before. Near impeccable engineering has gone into chip manufacturing. The Brodcom chips which have dominated the market since day one of cable internet have matured and are just incredibly well debugged. MSO/ISPs have been so used to these devices working flawlessly without latency or performance testing fo so long they just assumed the Intel Puma would work perfectly as pitched by the cable modem companies. Cable modem companies also had been working with chips that were flawless so long they were caught off guard. Shane is correct that there is no performance standard at all in the world for cable modem devices. That needs to change.

NO ONE was doing testing of these products until I came along with high temporal rate testing. That kind of test was also as far as I can tell new. Most testing involved statistics and averages. This super short spike mostly passed by normal testing. You had to really look carefully for it. So even the testing methodology was not there.. Everybody was near blind to the issue.

So they roll these out in the millions all over the world. Indeed people start complaining of odd issues. ISPs, modem vendors and chip makers run std tests, no one can see a issue.

Im doing very unrelated work on packet jitter for super high end audio and video work. Im watching packet jitter in nano second timing resolution using a scope. Im also for work doing super high performance networking systems for residential. Like $20-50K USD. Im pushing everything to its highest performance levels. One day I try something unsupported. I type in really low numbers for interval into Pingplotter. Ooooo. It works. I run tests at 100 pings per second.. Oooooo.. This shows things I had not seen before. So I start really using that full time to analyze network performance having no idea no one did that. I discover I can point it at the CMTS giving me a impressive view of cable network performance.

I leave that running at my house 24/7 on its own computer for YEARS running at 3 pings per second. Over time I see all sorts of stuff on the network.

Then one day last november, I get a new modem.. Oooo.. A SD6190.. OooOoo.. 32 channel... Ooooo... I swap it in and immd notice slow laggy page loads browsing the web. I look at Ping plotter and its horrifying. YEARS of perfect plots over 3 modems and a number of routers. Then suddenly, HUGE mess.. The Latency is literally off my scale.

I quickly isolate the issue and send emails to Intel and arris.. Dead silence. , They thought I was crazy.. I started posting very clear charts on DSLR and others reproduced my results and used different tools to also reproduce the results. Arris took notice.

Arris was shocked. They talked to Intel. Intel was apperently also shocked. In short order, and a few firmware tests we did on DSLR, it must have become clear there wa s a big issue. Then Mackey found the DoS and memory corruption reboot issues. 2 more things that caught ISPs and modem vendors off guard.

And then there was the Intel factor. Intel and Broadcom are very different in how they handle vendors and issues like this leaving modem vendors in the cold.

So... VM cant do or say ANYTHING about this issue. The modem makers cant say ANYTHING with the word Intel in it.

EVERYBODY is now dependant on Intel for patches. NOTHING can be done to speed this up. You can bet modem vendors are trying everything. ISPs are trying everything.. Intel is not budging. Im guessing they cant fix the issue as its a silicon problem. They need a new chip. Modem makers may already know this too.

So.. VM is looking at the worst mess its ever experenced. ALL of its puma 6 based devices might have to be replaced. There is no Intel box that will fix it. So they must replace them ALL with Broadcom based devices. Thats a HUGE issue for a number of reasons. There are not enough modems on earth to do this at the moment. Broadcom does not have the chips. Brodcom's production is not ready for this scale of emergency production. The costs to ISPs like VM are going to be enourmous. EVERY PUMA 6 box might need to be replaced. The labor alone is staggering. The time involved is going to add up.

IF Intel really cant fix it, and thats unknown right now, its going to be a HUGE mess on a scale worldwide thats never been seen before.

SO.... VM stalling out on this issue as everybody in the industry holds their breath as their life flashes before their eyes to see if Intel can fix it in firmware.is understandable.

I was told by a little birdie that Broadcom has vendors fighting for chips and its almost a free for all.

So... VM cant really do anything. Im not sure they know what to do yet. Like all ISPs worldwide they are praying Intel can fix it. Its looking to me after 9 months tho that maybe they cant.

So Shane is right.. VM cant do anything. They cant simply start giving out Broadcom boxes because they know they are about to vanish.

ALSO... Intel has a spare CPU in the Puma chip. This allows a ISP to run things in that CPU that you cant do with a broadcom chip. So there are features offered via Puma that they cant simply swap out going to a Broadcom solution. This is a big deal. This makes it near impossible to a ISP to use another solution besides Intel. Intel knows this too. They did this on purpose to hook a ISP.

Its a huge mess thats never occurred before.. Everybody is trying to figure out plans to deal with it and praying Intel can fix it.

[Xymox]

Interesting technical discussion on the Puma issues.. This really seems like a hardware limitation and not fixable in firmware..

Intel, ISPs/MSOs and cable modem makers,,, might be looking at the end of the world.. Of course im not a expert.. This page or so of discussion with Mackey who discovered the DoS and Memory corruption reboot atacks is very interesting. Seems pretty daming for the Puma 6 silicon..

https://www.dslreports.com/forum/r31122204-SB6190-Puma6-TCP-UDP-Network-Latency-Issue-Discussion~sta...

[PhilMull]

And still they take your perfectly good Router away and replace it with a faulty brick.

Not good.