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]

[wotusaw]

Thanks for the link. I shall post this on the gaming clansite I belong to...... Every little helps.:)

I titled the post 'USA joins UK in Puma 6 chipset posting rampage!'

https://pastebin.com/gLXGAmBA

Wow, that's alot of bad vibes right there.

I also have read of the legendary graphs and wotnot produced by 'xymox1'. Nice work. Keep socking it to the great and powerful wizard Intel. 

[Kippies]

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@legacy1 wrote:

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@Xymox wrote:

Intel must be reading this with fear. The forces are uniting against them from across the pond.. 🙂

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their not going to lose sleep over this...

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Key driver is cost. Its a SOC. Costs very little and KIND of works. I doubt even the like of Arris who have shipped x million units worldwide are putting much pressure on Intel.  Whilst yes its a bad press dealio, as none of us have any SLA's on our residential contracts its going to continue to go by the board. And its not exactly sexy is it?

"Gamers allege 200MS spikes in latency are responsible for missing already crappy hit boxes" isn't going to make the DM any time soon. Joe Public is too interested in the Kartrashians. Such is life....

AS we dont have any proper class action legislation over here its really all eyes to our Murrican cousins to see what the next step is...

[boltedenergy]

and here it is - https://www.classactionlawyers.com/puma6/

[DarkBahamut]

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@Peter_JS wrote:

Hindsight being a wonderful thing, but I'm finding it hard to understand how this was missed by Intel, Arris and then the ISPs before so many devices are manufactured and rolled out. 

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It wasn't missed, they knew about it as it was highlighted during testing. I assume they figured it wasn't a big enough issue for them to worry about which is largely backed-up back the lack of action on the issue over the last ~18 months.

We'll just have to look forward to the next hub (and whatever problems that comes with  )

[Xymox]

🙂

The next Register.co.uk story will have to include links to this forum. I will make them aware.

At some point this will spill over onto main stream press. We have started class action lawsuits over here and if the Puma 6 cant be fixed this might well be the biggest mistake in Intel history with millions of units shipped. The cost of eating all those modems in some sort of recall or the cost a big class action lawsuit combined with the face plant they have done in front of all the modem makers and ISPs *WILL* hurt them. The "Connected Home" division is the big focus for Intel as the classic CPU buis is dying and they dont have much foot print in mobile. And this division just did a impressive face plant that might end up costing more then we may ever know and maybe change the direction Intel takes for the future.

The reason Intel and Arris and Virgin did not catch it is there are *NO* standards in place for DOCSIS modems for performance. They meet spec even if they dont pass UDP at all. There simply are no testing procedures at all for performance. SOOO no one was testing AT ALL. As utterly insane as that sounds its 100% true. Ive talked to a lot of people, even some who make modem chips, no one was testing for performance because there is not standard for performance testing and no requirement for it.

We have all changed that now. Now ISPs and modem makers are using the same tools I used. Also EVERYBODY in the industry knows we will all test devices now and post.

The other important thing is that everybody now knows latency is more important then speed in many things. Like gaming. Latency and jitter are far more important then bandwidth for most uses. So i think now ISPs, modem makers and chip makers will be tuning for latency, not just speed.

YES.. A mistake has been made. There was a huge oopsie. Broadcom has killer chips. Im using a Arris sb8200 and its the best specs known to man for cable. The Intel foray into cable modems was a impressive face plant. Nothing like this has ever happened before. ISPs and modem makers are kinda in shock. Intel is telling them they can fix it, 5 months later and 2 firmware updates and, nope.. The months ahead will be interesting to see what happens. Something has to give.

Can you guys PM me and we can exchange info so we can coordinate and share results.

[ItsCraigo]

It's another test of the responsibilities and customer service standards of VM. They have made themselves directly responsible of this Intel issue because they chose to create and market a bespoke high-end service in the form of Vivid gaming and charge a premium for this service backed up by SH3 which they know has fault issues but still continues to market this faulty product. This puts them in the hot seat as they follow Intels trend of continuing to sell a product they are aware will cause the end user a detrimental experience for the very purpose they are paying extra per month on their package.

[Pasbags]

I remember when we had NTL broadband separate modem and I believe a Linksys WRT54G that was always super reliable be good if virgin actually did separate modem's again as an option even if you had to pay a little extra instead of router/modem combo 

[JJC1138]

Just in case anyone from VM is reading this, I for one am planning to cancel my service as soon as I have some spare cash to pay the early termination fee. I don't even want to wait until the contract ends. I'm baffled that they launched a service specifically marketed for gaming with hardware that is so unsuitable for the task. Even the BQM graphs I've seen from people using the SH2ac show a level of jitter that is very unimpressive compared with other broadband services. I don't know if it's technical incompetence that the engineering department didn't notice the problem, or if they did understand and were just overruled by higher ups, but the end result is the same.

[shanematthews]

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@Xymox wrote:

The reason Intel and Arris and Virgin did not catch it is there are *NO* standards in place for DOCSIS modems for performance. They meet spec even if they dont pass UDP at all. There simply are no testing procedures at all for performance. SOOO no one was testing AT ALL. As utterly insane as that sounds its 100% true. Ive talked to a lot of people, even some who make modem chips, no one was testing for performance because there is not standard for performance testing and no requirement for it.

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So, let me get this straight, there are no set standards for DOCSIS modems in relation to performance, so there are no regulations that state that the modem has to provide x level of service, and you think people will have a case against intel in relation to modems that don't meet standards that don't exist? 😛

I don't think intel are too bothered by this class action lawsuit stuff then, they haven't failed to meet any standards as you yourself admit there aren't any in place to begin with, the absolute best case scenario for that lawsuit is they order the FCC and similar bodies to create standards, which will take a long time anyway so won't solve the hub3 issues and wouldn't even be live by the time the hub4 arrives

[shanematthews]

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@ItsCraigo wrote:
It's another test of the responsibilities and customer service standards of VM. They have made themselves directly responsible of this Intel issue because they chose to create and market a bespoke high-end service in the form of Vivid gaming and charge a premium for this service backed up by SH3 which they know has fault issues but still continues to market this faulty product. This puts them in the hot seat as they follow Intels trend of continuing to sell a product they are aware will cause the end user a detrimental experience for the very purpose they are paying extra per month on their package.

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Because they have to market the hub 3, they don't have any other devices on offer, they aren't going to order in hub2's so we're stuck with them until they decide to roll out the hub4, like it or not, there isn't anything that we can do to change this, especially not while VM hold the monopoly on the cable network, and thats never going to change