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]

[cje85]

The test results and feedback posted over the last few weeks show it actually fixes (or at least massively improves) the latency and isn't just a mask.

[mercuryin]

I can´t understand how people can say that the problem is solved. I have attached a few times graphics in the past few days, I also have a ticket support opened and no response from Virgin Media. Being honest I can see improves with the last firmware but not enough if you a are a gamer like me to keep your contract with Virgin actually. I will have coverage with another company soon, ( I´m not going to say the name here ) and I will switch immediately if Virgin do not resolve my latency issues in full. 

[ILuvNips]

The majority have said it's fixed their issues but I think I've seen 2 posters state that the firmware update for them has improved the issue but not fixed it. Make of it what you want. I've been looking at moving over to BT as I'm also in an over utilised area requiring a "CAT-C", what ever that is and from past threads that I've seen which have also required a "CAT-C" these have been unresolved for 3+ years.

For my area Vodafone offer around 60Mbs for £26, anybody have any dealings with Vodafone before? Not the speeds that I could in theory get with Virgin but after a while you get tired of drinking watered down beer and want the proper strength stuff so I've sent Vodafone an enquiry to see what would actually be involved in moving over and keeping my number. Shame really as I've been with Virgin since the old Videotron days.

[Luke_113]

@ILuvNips its the direction that Virgin Media have decided to take, I don't doubt the lack of action over the past 2 years from them isn't accidental, they don't want people such as those that post in this thread understanding problems and being able to explain it to the masses in a way we can all get our heads round.

This is proved by the way that call centres will act like they don't know what you're talking about when you talk about the Intel Puma 6 issue, and just tell you nothing is wrong etc...
In the meantime the forum/phone staff will just send an engineer costing us the customers more money over time.

I too am in the process of getting a line put in for DSL based connection, I'll forgo the 160mb download difference to what I have now for stability, and I'm well aware that BT have their own issues but in the 4-5 years I had an infinity line I had so many less issues and problems than I've had with Virgin

[mitch84]

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@ILuvNips wrote:

The majority have said it's fixed their issues but I think I've seen 2 posters state that the firmware update for them has improved the issue but not fixed it. Make of it what you want. I've been looking at moving over to BT as I'm also in an over utilised area requiring a "CAT-C", what ever that is and from past threads that I've seen which have also required a "CAT-C" these have been unresolved for 3+ years.

For my area Vodafone offer around 60Mbs for £26, anybody have any dealings with Vodafone before? Not the speeds that I could in theory get with Virgin but after a while you get tired of drinking watered down beer and want the proper strength stuff so I've sent Vodafone an enquiry to see what would actually be involved in moving over and keeping my number. Shame really as I've been with Virgin since the old Videotron days.

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I think thats one of the problems, some say its fixed, my own experience on .603 is positive, i have played tons of BF1 on PS4 over wifi and its been perfect, the same as when I was on my older superhub1.

Some of the peeps that say its only improved may also be in an over subscribed area which will never give a true reading if the firmware has fixed the issue.

As it stands I believe the issue is fixed in the latest firmware, and I'm not in an over subscribed area.

[nickking]

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@mitch84 wrote:

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@ILuvNips wrote:

The majority have said it's fixed their issues but I think I've seen 2 posters state that the firmware update for them has improved the issue but not fixed it. Make of it what you want. I've been looking at moving over to BT as I'm also in an over utilised area requiring a "CAT-C", what ever that is and from past threads that I've seen which have also required a "CAT-C" these have been unresolved for 3+ years.

For my area Vodafone offer around 60Mbs for £26, anybody have any dealings with Vodafone before? Not the speeds that I could in theory get with Virgin but after a while you get tired of drinking watered down beer and want the proper strength stuff so I've sent Vodafone an enquiry to see what would actually be involved in moving over and keeping my number. Shame really as I've been with Virgin since the old Videotron days.

---

I think thats one of the problems, some say its fixed, my own experience on .603 is positive, i have played tons of BF1 on PS4 over wifi and its been perfect, the same as when I was on my older superhub1.

Some of the peeps that say its only improved may also be in an over subscribed area which will never give a true reading if the firmware has fixed the issue.

As it stands I believe the issue is fixed in the latest firmware, and I'm not in an over subscribed area.

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I wouldn't say it's 100% sorted but it's a hell of a lot better, I've had no issues on BF1 on the Xbox One since the firmware update where as I was getting it all the time before.

[planetf1]

I force rebooted, still on BA3. I subsequently had a stack of power fails (RCD trip) due to a fault.. But still on BA3 (with Vivid 350)

It seems like doing a factory reset (from GUI) should get me 605/608 in a few days.... I wonder what the risk of being stuck on <archaic> firmware is?

It's a shame the trial team didn't get back to us to confirm the recommended way forward when the trial ended. Other orgs I've been with for trials (like BT for example) were always very clear about this

[Guybrush85]

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@mercuryin wrote:

I can´t understand how people can say that the problem is solved. I have attached a few times graphics in the past few days, I also have a ticket support opened and no response from Virgin Media. Being honest I can see improves with the last firmware but not enough if you a are a gamer like me to keep your contract with Virgin actually. I will have coverage with another company soon, ( I´m not going to say the name here ) and I will switch immediately if Virgin do not resolve my latency issues in full. 

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I can't get it to spike with the frequency it did and looking at your image, neither can you. I can't get it to spike to the level it did  and neither can you (those sub 100ms spikes aren't exactly game breaking) and your results aren't taking into account the known latency within DOCSIS and TCP Buffering. 

I can't get it to break (see my posts) and the issues I've noticed in gaming aren't occuring (granted I've changed games several times since the start of this saga), so that's how I can say it. 

[Pro4TLZZ]

how can I improve my connection?

https://www.thinkbroadband.com/broadband/monitoring/quality/share/a25d02123e576218301eb92415615e79f7...

[Andrew-G]

Pro4TLZZ: "how can I improve my connection?"

Move to an Openreach based ISP if you've got the prospect of decent speeds (you won't notice the difference between 50 and 100 Mbps in daily use, IMHO).  Or you wait for the fabled firmware to trickle down to those of us on slower speeds.  That may take a while - I understand that the firmware goes under the internal codename of "Godot" (that's a performing arts joke, for those who don't spot it).