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]

[Pikeyp]

I think someone else posted a while back that the roll-out was in 'batches of 10,000' so you could well be in the same area and not get it at the same time.

Hasn't made much difference to me, I still get drop outs all over the place ... today so far for example!

[nidstigator]

I am so confused- nothing on the Puma6 thread on DSL reports suggests the issue was fixed by intel (other than masking it for ICMP)

Did anyone here confirm it's fixed for TCP, UDP and ICMP? 

[cje85]

The Beta firmware released in October 2017 was just an ICMP fix which masked the problem, but the version now being rolled out is a real fix as shown by the majority of the test results and feedback posted here.

Intel have also confirmed in a US court filing, back in March, that they have resolved the issues.

Intel argues that "[i]f Intel's internal improvement efforts were to become public, third-party competitors would be able to use Intel's own internal analysis, which they ordinarily would not be able to access, to disparage Intel's Puma 6 chipset and spread fear, uncertainty, and doubt in the marketplace relating to the Puma 6 chipset and latency issues that Intel identified and already resolved.

https://www.leagle.com/decision/infdco20180322c21

[johnthecyclist]

I received the update early this morning! Area 20

[nidstigator]

Holy ****! I had no idea this happened- thank you so much for the info! 

My frustration with this issue led me to leave VM back in Feb. Might check them out next time my contract is up. 

[Andrew-G]

Great contribution cje85, but I wanted to respond to the Intel quote: "third-party competitors would be able to use Intel's own internal analysis, which they ordinarily would not be able to access, to disparage Intel's Puma 6 chipset and spread fear, uncertainty, and doubt in the marketplace "

Intel don't need to worry about competitors.  They need to worry about seriously cheesed off customers.  "Intel inside" now seems to mean "Problems inside - wait to see when your's becomes public knowledge".  I now regard the following brands as heavily tarnished: Intel.  Virgin Media, Arris.  These companies conspired to release a crap product that should never have seen the light of day, they ignored early customer feedback.  And end-to-end, it has taken the miserable collection of dullards two years to fix.  In my case, I only had to endure the problem for eight months, that was bad enough.

Problems occur in any business, and the more complex the business and supply chain, the more chance of problems  I can live with that - I work for a similarly complex, large volume customer service business.  But how a company is perceived rests mainly on its service recovery - how it deals when those problems do occur.  Intel, Arris and Vermin Media could have communicated with customers, explained the problem, the plan, and the progress.  But no, they collectively stuck their corporate heads somewhere dark, moist and fragrant.  The actively refused to engage with customers.  They put their own employees in the firing line without adequate information.  Even today, we haven't had an honest apology for the shockingly poor service.  VM's executives cower behind their poor rewarded frontline employees, but I'll wager still pay themselves vast, undeserved bonuses.

On this basis, who realistically expects VM to learn, and specify a decent Hub 4?

[KryptoLogic]

I only received my SH3 last week and would have thought it would have had the latest Firmware Update Installed but, no such luck so I wonder when their going to roll out to Area 14?

[ocleot07]

Grandparents upgraded from 100mbps to 200mbps about 1 month ago. They all ready had a SH3 but never had any real issues (they only stream netflix/amazon). They got the update in the early hours and it's now looking good. 

area 1.

[nifnat]

So I got updated to version .608 a few days ago. I was on .116v beforehand so I don't have any idea how .603 would perform for me but my experience with .608 has been a disaster. With normal usage (web browsing, Netflix, Youtube) I have noticed no difference but with gaming it has been an awful experience. With the past firmware's I always felt that sometimes things were a little off  compared to playing on an OpenReach FTTC connection but never really had much conclusive proof.

Now with this newest firmware games are unplayable at times. Rainbow Six Siege is a good ,but not only, example of this. On previous firmware's it felt alright playing but now every 10-20 seconds I get massive lag spikes and the games indicators for network issues come up. I've never had this happen before even at peak times.

It does not surprise me that a year and a half down the line we get an update that makes things worse. Having heard good things about the .603 firmware I hope that this issue can still be resolved but I really am losing my patience with this issue. I do realise that the firmware update might not be the only thing causing this issue for me but with how these issues only cropped up as soon as the update hit I find it very likely it is the culprit.

[Touhoufan]

I was so close to getting the update... but it failed to download anything!

 Failed Before Download - Server not Present