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]

[TROTER]

Just great SH2AC a limited resource, you could not get one for love nor money now there sending people three of them?  Please return your surplus stock of SH2AC's so that others may be able to benefit. 

[eddiechatburn]

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@TROTER wrote:

Just great SH2AC a limited resource, you could not get one for love nor money now there sending people three of them?  Please return your surplus stock of SH2AC's so that others may be able to benefit. 

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I wish I'd thought of that...!

  

[chrisxp]

watusaw wrote:

Yours is much better actually. Not as good as the SH2ac but alot better than the 200/20mb gamer package. I can't see 330/20mb package on my Virgin page yet so presume not available in my area yet? I'd get that just for a quick temp half fix.

I've seen other 300/20 graphs and they are similiar to yours. Basically half the pretty yellow of the 200/20 gamer(lol u r kidding!) package.

I used to play Battlefield but went over to Titanfall 2. Just because my clan plays that one mostly. If your a sniper then this won't effect you much. It's the lightning face to face stuff where the pain is felt mostly. I'm an average player prone to fits of rage and biting things.. Possibly the better you are the less the pain anyway.

 Hi.. It's not actually a package, I am on gamer 200. I called up to query why a friend got a free speedboost from 200-300mb for free and I didnt, so they applied it to my account 🙂

I rarely snipe and 99% of the time in the front line, with loads of face to face. I guess I may be a little luckier than others.

Can the sh2ac still not support 300mb?

It does list as vivid 300 on my account though if that helps in asking. My router version is 9.1.116V for reference

Here's my BQM after running all night/day:

[nallar]

It's dependent on other sources of latency local to you - CMTS type and firmware, the link between your headend and the rest of vm's network, local congestion levels.

Swapping from 200/20 to 300/20 doesn't improve latency for an idle line. It may slightly improve latency if you're using a significant portion of the download. It's also not currently offered for 2ac users unless something's changed/I was lied to - I had to downgrade back to 200/20 to use the 2ac.

[chrisxp]

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@nallar wrote:
It's dependent on other sources of latency local to you - CMTS type and firmware, the link between your headend and the rest of vm's network, local congestion levels.

Swapping from 200/20 to 300/20 doesn't improve latency for an idle line. It may slightly improve latency if you're using a significant portion of the download. It's also not currently offered for 2ac users unless something's changed/I was lied to - I had to downgrade back to 200/20 to use the 2ac.

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Hi, I'm in a new area, was completed in September 2016 and that's when I signed up, so presume its all new equipment. I'm also <10m from the street cabinet.

My BQM for the past 24hours is here:
https://www.thinkbroadband.com/broadband/monitoring/quality/share/462e2da7ae28cfbfedffa92f4ad5859210...

Guess I may be one of the "better off" customers. I do use significant bandwidth nearly 24/7 as I have iptv running constant.

To whatusaw; I don't snipe and prefer face2face combat and have never felt any issues, always been the same really from sky -> virgin.

[DarkBahamut]

The >300Mbps services won't be offered on the 2ac because it can't bond to enough channels and it leads to plenty of load issues on the network. VM are at least doing something right if they make VIVID 300/350 customers downgrade when moving to an 8x4 modem.

[BrokenFibre]

Below is my BQM on the 200 Gamer package on a good day.  Just spoke to their technical department and an email has been sent to my area's 'area manager' to see if they have any SH2ac they can supply me with.  We will see what happens.

Problem number 2 is the Gamer package + Full TV.  I no longer want the TV but retentions and customer relations cannot remove the TV package without either dropping me to 200/12 or putting me on 300/20 (which as we know is not possible on a SH2ac) as the 200 gamer doesn't exist anymore.  

I also want to stay on my monthly 30 day rolling contract.  At a loss as to what to do as my previous VDSL connection with Plusnet while good for 14 months suddenly lost 20Mb downspeed and 8Mb up speed as despite multiple reports to them just kept saying the issue was sorted which is wasn't is the reason I moved to Virgin Media (plus at the time I wanted live TV again which now I don't as I don't use it).

Retentions did say that trials of new firmware (yesterday via internal email) had been sent to around 100 employees to test...take that info as you will.

[wotusaw]

crispxp

This is my broadband graph. It's always like this....as you can see it's about 2x worse than yours. You do seem to be fortunate with location and wotnot. I am in yellow hell at present.

[wotusaw]

brokenfire wrote:

"Retentions did say that trials of new firmware (yesterday via internal email) had been sent to around 100 employees to test...take that info as you will."

That's just wonderful. Hope at last after so very very very very very very very very very very long. 

All I want to do is kick *** in Titanfall 2 (livefire and pilot vs pilot modes). Is that too much to ask for £87 a month?

[Oooch]

Where did you see brokenfire's post? How long ago was it?