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]

[Xymox]

"When large companies abuse their dominance of the market, it causes direct harm to consumers. The court's ruling issued a strong reminder that such behavior is illegal and unacceptable," said BEUC director-general Monique Goyens. This would include not only Intel, But Virgin Media. If VM colluded with Intel or modem makers to allow Intel to become a monopoly thats serious.

It looks like these guys might need to get involved http://www.beuc.eu/

[legacy1]

I've no doubt this can and likely has been solved in modem mode but my guess is they are delaying the fix for that due to them wanting router mode to work and the reason is VM don't want people buying routers for modem mode because they want the public wifi to work.

[boltedenergy]

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@legacy1 wrote:
I've no doubt this can and likely has been solved in modem mode but my guess is they are delaying the fix for that due to them wanting route mode to work and the reason is VM don't want people buying routers for modem mode because they want the public wifi to work.

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That public wifi gambit of theirs is total BS, totally unnecessary security risk and potential speed drain for VM consumer users. Yes they claims its all secure and doesn't affect your bandwidth, I would love to see the facts to back that up other than a sly marketing man promise.

[boltedenergy]

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@Xymox wrote:

Thought i would point out again that im using web beacons.

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an honest thank you for all your work on exposing this issue to a wider audience.

I think the biggest issue for me was the upgrade to the gamer package 'needed' a HUB3. This HUB3 which has been shown to be a terrible piece of hardware thanks to Intel and the incredibly dodgy latency issues. This has been misleading advertising and no help to gamers, in fact its a downgrade due to the latency problems. Or for anyone who cares about having their time sensitive traffic communications function as expected.

Not to mention VM knew about this potential problem from the start when the HUB3 was in beta trials. Users were already complaining then, but it was ignored and the HUB3 was pushed through to mass market. That's holding contempt for your users, if nothing else!

[Xymox]

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@legacy1 wrote:

I've no doubt this can and likely has been solved in modem mode but my guess is they are delaying the fix for that due to them wanting router mode to work and the reason is VM don't want people buying routers for modem mode because they want the public wifi to work.

---

Well no matter what on a RF level in modulation there is a fixed upper bandwidth and so any additional traffic causes some amount of disruption to the main users flow. It would cause some increases in latency. If they are doing that with a Puma,,,, well,,, thats a HUGE issue as i have shown clearly with testing that the Puma is horrible with concurrency. IE doing more then one thing at the same time.

You can see that even tiny amounts of traffic will cause the entire Puma modem/gateway/wifi router to fall over with some types of traffic. So the main ower of the Puma modem/gateway will for sure feel the effects of a public user.

 

Yea that public bit is a horrendously bad idea with a Puma... Broadcom, it would be fine.. Sorta.. But not a Puma.. They will need to use a VPN and we know VPN's have issues on Pumas as well..

[Xymox]

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@legacy1 wrote:

I've no doubt this can and likely has been solved in modem mode

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I assume your talking about the DoS/Reboot 0-day ? The 250ms spike and all the performance issues are another matter completly and I know someone now who makes modem chips and they dont think that can be fully fixed in firmware where they would be a equal to Broadcom.

[Xymox]

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@boltedenergy wrote:

Not to mention VM knew about this potential problem from the start when the HUB3 was in beta trials. Users were already complaining then, but it was ignored and the HUB3 was pushed through to mass market. That's holding contempt for your users, if nothing else!

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Its amazing to me that despite knowing right at the beginning, and it happened in every major market at every ISP, somehow Intel got them to not only approve the devices, but they became a monopoly overnite. I really think someone was paying someone.. A never before tested chip that had never been used before anywhere somehow went into every major market in one year as a monopoly. Even as we speak Intel is taking more orders for Puma 7s then they can manufacture. Sales are thru the roof. Amazon has not pulled products and they are the best selling modems. ISPs are pushing them into homes as fast as they possibly can. ISP are entering new markets with them as the only device they can use, like home automation, security, power monitoring, IoT hubs. Its FULLY out of control..

Its quiet the disaster in progress.

[Xymox]

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@Xymox wrote:

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@legacy1 wrote:

I've no doubt this can and likely has been solved in modem mode but my guess is they are delaying the fix for that due to them wanting router mode to work and the reason is VM don't want people buying routers for modem mode because they want the public wifi to work.

---

Well no matter what on a RF level in modulation there is a fixed upper bandwidth and so any additional traffic causes some amount of disruption to the main users flow. It would cause some increases in latency. If they are doing that with a Puma,,,, well,,, thats a HUGE issue as i have shown clearly with testing that the Puma is horrible with concurrency. IE doing more then one thing at the same time.

You can see that even tiny amounts of traffic will cause the entire Puma modem/gateway/wifi router to fall over with some types of traffic. So the main ower of the Puma modem/gateway will for sure feel the effects of a public user.

Yea that public bit is a horrendously bad idea with a Puma... Broadcom, it would be fine.. Sorta.. But not a Puma.. They will need to use a VPN and we know VPN's have issues on Pumas as well..

---

Man.. I would love to test that.. Easy to setup a test. Run ping plotter TCP on the Puma on the modem/gateway owner side. Then hook up wifi and run various tests to see what effects that has on the owner latency.. My guess is its pretty shocking.. If anyone tries this test remember you CANT USE ICMP PING based tests. You have to use a TCP or UDP based test. On the public side just running a speedtest should do it.

[Xymox]

Man.. I would love to test the VM public wifi thing. Easy to setup a test. Run ping plotter TCP on the Puma on the modem/gateway owner side. Then hook up to public wifi and run various tests to see what effects that has on the owner latency.. My guess is its pretty shocking.. If anyone tries this test remember you CANT USE ICMP PING based tests. You have to use a TCP or UDP based test. On the public side just running a speedtest should do it.

[wotusaw]

 shanematthews wrote:

'Also, branson doesn't own VM and hasn't for a long time, Liberty Global, an american company, owns VM'

I never mentioned Branson. Was actually thinking of cable cowboy tycoon John Malone..yehaaaaa. He is seriously rich.

 Is'nt that Xymox one clever dude, eh Shanematthews. 

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[wotusaw]

'Also, branson doesn't own VM and hasn't for a long time, Liberty Global, an american company, owns VM'

I never mentioned Branson. Was actually thinking of cable cowboy tycoon John Malone..yehaaaaa. He is seriously rich.

 Is'nt that Xymox one clever dude, eh Shanematthews.