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]

[Andrew-G]

StopItRawr: "Nowadays in the era of HFT and algorithm based systems deducing trading signals, it's very much needed."

I beg to disagree.  I've worked for many years supporting the director of large listed companies with big, regulated customer facing operations, including several names you'd all know (not in the telco sector, to be clear).  I've worked very closely with the investor relations teams in those capacities, and been Head of Business Research for a large City firm.  I can assure you that HFT and algorithmic trading does not rely one iota on specific terminology like RGU - it can cope with customers, accounts, RGUs, lines, units whatever, even where it relies on raw published data at all.

So RGU is not needed for any reason - but it is symptomatic of the fact that to Liberty Global and Vermin Media's management, that is all we are.  That's why they don't care about the crap customer service.  That's why Ofcom complaints have doubled in the past two years.  That's why they aren't going to fix the Hub 3.  Of course, some people have it worse - imagine what the company refer ti its staff as, when not addressing them face to face.  My guess is that VM employees are each a UCU (Unwanted Cost Unit).

[Luke_113]

hahahaha @Andruser I did chuckle outloud at UCU, because its likely accurate

[Luke_113]

I have just seen via another post on this forum, which I expect will probably be removed relatively fast by forum mods (funny they remove some posts within minutes/hours but take 7 days to respond to threads where actual help is needed)

https://www.reddit.com/r/VirginMedia/comments/7xzbay/virgin_media_super_hub_3_intel_puma_bug/

Worth the read

I would not imagine that many people doing this would make the Exec office reconsider their stance on not trying to resolve the Puma 6 fiasco

[tommey]

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@Skunkfuwrote:

Hello all,　

I have cancelled my cancellation with BT and cancelled VM order.　

Good luck everyone.

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Trust me you did the right thing just look below at my VM & BT BQM's

[Skunkfu]

Thank you for kudos/thumbs up everyone!

Few more things that might be of interest to some people. When things are not the way they should be any bit of info is good.

Even more than a week before installation I was put to retention department. The guy on the phone was very professional, we had a nice chat and covered all of my concerns and reasons for leaving.  Please take this info with a grain of salt but the person without my input mentioned SH4. Basically what he said is that it is not confirmed by the bigwigs however, there are talks going in their office about SH4 in the near future.

Now take this info seriously because I know this person for many years and his information is 100% correct.

This might not be big news to some but BT are rolling out full fiber optic broadband connections all the way to your property. This is not only for new builds! Existing streets/properties in central London are being upgraded to 300Mbps right now.

This will challenge VM monopoly of their "super fast" broadband and will give people more choices. VM are winning the battle right this moment, but the war is not over :]

[davtom]

It's good to see this thread. I have a Superhub 2 and a Tivo box. I've applied for an upgrade to the V6 box and the documentation that came through has indicated that a Superhub 3 will be allocated as well.

I'm on Vivid 150 and I seem to be able to get the contracted speeds at all times so I don't need the new superhub. Based on the contents of this thread, I'd rather keep the existing one. I phoned customer services up earlier today to arrange this. The person I spoke to asked me why I wanted to keep the superhub 2 and I explained my concerns about gaming. (Actually I'm a software engineer working with WebRTC which powers a lot of video conferencing and I know that ping jitter also negatively affects that, since it causes WebRTC to reduce its estimated bandwidth. This library is behind Hangouts and is used by many more applications; it's in-built into many modern web browsers.)

Anyway, the point is that the person I spoke to said he would arrange to have the new modem removed from the scope of delivery. A few hours later, I've received an email with an attachment that still has the superhub 3.0 on it.

Should I go through the exercise again or should I accept what comes and ask someone to reactivate the superhub 2 if I notice more problems with online gaming?

I'm self-installing so nobody will take the old modem away.

[Sephiroth]

As far as I can see, the SH2 will not have been deactivated - otherwise you'll be without Internet. So just ignore the Hub 3 unless I'm wrong.

[RidingTheFlow]

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@davtomwrote:

Should I go through the exercise again or should I accept what comes and ask someone to reactivate the superhub 2 if I notice more problems with online gaming?

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Just don't connect & activate SH3 - keep using SH2 even if SH3 arrives. I don't have TV myself but from what I've heard V6 should work with SH2 just as well (its simply needs it for internet connection after all).

Afterwards you can inform VM that you intend to keep SH2 - and they most likely will just ask you to send SH3 back (there should always a return label in the SH3 box and new seal tabs for returning).

[RidingTheFlow]

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@Skunkfuwrote:

This will challenge VM monopoly of their "super fast" broadband and will give people more choices. VM are winning the battle right this moment, but the war is not over :]

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Not convinced about "challenging monopoly". From what I've seen up to now, BT is not very keen to roll out superfast/Infinity where "superfast already available" (e.g. VM-covered areas). For that reason area where I live (and couple neighbour ones) were officially excluded even from FTTC rollout, not to mention FTTP - and apparently this is regulator-approved policy.

[RidingTheFlow]

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@Skunkfuwrote:

Closed system setup with poor quality connection is a poor service in my opinion so I have cancelled my cancellation with BT and cancelled VM order.　

My guess on VM reaction to such - "great, one too clever/troublesome customer avoided" 😉