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]

[acheronte]

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@Boygrouchowrote:

The only way to get a sh2ac is to go through to retentions and ask to give 30 days notice to cancel your service (and be happy if they say OK).

Only then do they seem motivated to send you one.  This will involve transferring you to the BB "specialists" there are a few of them who will arrange it.

But not before they have messed you around with promises of call backs etc.

Its a slow and frustrating process...it actually feels like they are taking the proverbial and having a laugh at your expense.

While the SH2ac has greatly improved my gaming experience I think I will leave anyway just for the appalling CS.

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This guy gets it. If you're a gamer, leaving by principle should be the only course of action, as VM will only start to listen when they start losing money. As far as the stakeholders are concerned, we're just muttering monkeys, easily dismissible as "just gamers". When they start seeing the gamer demographic leave en masse, then they'll take the complaints seriously, or if they're publicly called out on social media (Facebook pages etc.).

As of me, I have I'll have my Sky line up and running in 2 days, so my gaming woes will be sorted and will finally get rid of VM and all the lies and empty promises. I'll post a BQM for reference sake.

[Anonymous]

You do have to love that the worst major provider for gaming is the headline sponsor of EGX.

[tommey]

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@Anonymouswrote:

You do have to love that the worst major provider for gaming is the headline sponsor of EGX.

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Indeed however the state of that BQM is shameful for a so called business service.

[tonycv51]

From a quick look on eBay there are quite a few Superhub 2 AC's for under a tenner.  If it's so hard to get one from Virgin has anyone ever bought one via this route and then managed to get Virgin to activate it ?

[Springer1]

I wonder who actually owns these routers, think we may know,  that aside can they not be placed behind the hub3 set in  modem mode,  without involvement from our genial, ever  helpful host? A shade of sarcasm there, sorry , but I blame them for my total loss of hair which has happened this last two weeks, lol do have to admit I did pull it myself out of shear frustration,  but at least I own up to my failure and actions, not like VM!

Springer

[philjohn]

People have tried, and failed.

[Springer1]

People have tried, and failed.

Can you be a little more explicit please, is that getting VM to reactivate a second hand model or using one behind a hub3?

Springer

[Andrew-G]

VM won't reactivate a SH2 or 2ac for modem use UNLESS IT WAS ORIGINALLY ISSUED TO AND ACTIVATED ON YOUR ACCOUNT.  So the cable modem side of an EBay SH2ac will never work again.  You can argue that's not fair, but it is VM's property, their network, their rules.

However, if you connected an Ebay SH2ac on the customer side of a Hub 3 that itself was in modem mode, you could use the SH2ac as your router, and that would work without needing VM to activate it.  You would have no benefit over using the Hub 3 router and the Hub 3 latency issues would still apply but it would work as a mediocre router (or as a mediocre access point if the Hub 3 was in modem/router mode).  There's a walk through somewhere in the forums of how you can do this, but it is fairly pointless if you need to buy the thing, because it'd cost you a tenner for an ancient and sub-par wifi device, when £25-30 you could buy a better performing brand new and guaranteed standalone router or AP.  

[viper]

Hi everyone, sorry for the question I've read about 20 pages of this thread so far, but can anyone advise if running a separate router with the SH3 in modem mode is any better in terms of reducing the ping?

[Guybrush85]

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@viperwrote:

Hi everyone, sorry for the question I've read about 20 pages of this thread so far, but can anyone advise if running a separate router with the SH3 in modem mode is any better in terms of reducing the ping?

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Afraid not mate.