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]

[Sephiroth]

I suspect that there is a considerable amount of discussion between VM and LG. The facts are:

1. Both VM & LG understand the Puma 6/7 CPU issues.
2. They both understand the reputational issues that arise.
3. The Hub 3 is officially the "Hub 3.0".
4. VM have said that DOCSIS 3.1 will be a premium product when launched.

Among the reasonable speculation is:

a) A hub "3.1" will be for DOCSIS 3.1
b) VM/LG are considering options for their DOCSIS 3.1 hub or modem
c) VM/LG want to improve their customer image by taking the right decisions
d) Above all, VM?LG in the UK want sweat their assets and move on only when competions demands

[Andrew-G]

I'd agree with all those points, Seph, except this one: "VM/LG want to improve their customer image by taking the right decisions"

They know full well that the Hub 3 is causing grief for some customers, but they are equally adamant that they won't do anything to either resolve that themselves, or (eg) allow customers to solve it by buying their own modem.  Likewise, they are fully aware of the poor performance and reputation of their offshore customer support - but they don't do anything about that.  They are similarly aware that many installs are being done to a dismally low standards, that the street cabinets are poorly maintained, but they don't do anything about that (well, I suppose they do if gaffer tape to hold a cabinet shut counts as a proper solution).  They know there's widespread connection speed issues and could automatically identify when individual connections have speed problems and proactively fix them, but they don't.

VM are in a position of continuing net gain in customer numbers, and in many places they have a struggle to serve the traffic they already have, there simply is no commercial case to do anything to improve their customer image, and whilst the D3.1 offer will be premium priced, I'll be very surprised if the hub is a premium product.  In fact, I'll go better than that - if the D3.1 hub is a premium product (by which I mean decent, reliable modem, fast, full functioning interface capable of properly managing connections, with strong, reliable wifi capable of mesh operation, the lowest latency we can expect via DOCSIS, and automated diagnostics communicated to the networks team) then I WILL EAT ONE.  I'm sure you'll agree that VM/LG will do for the next hub what they've always done - nail down a minimal specification based on one of Hitron or Arris' cheaper efforts, cut every feasible corner, repackage in a custom casing, aiming for an average price below thirty quid, leading to a really mediocre affair that delights nobody?

[Sephiroth]

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@Andrew-Gwrote:

I'd agree with all those points, Seph, except this one: "VM/LG want to improve their customer image by taking the right decisions" [SEPH]: It was just speculation.  A normal business would want to do what I've speculated.

They know full well that the Hub 3 is causing grief for some customers, but they are equally adamant that they won't do anything to either resolve that themselves, or (eg) allow customers to solve it by buying their own modem.  [SEPH]: The cost of issuing hundreds of thousands of non-Puma hubs would financially break them or nearly so.  Their remedy here is the class action taking place, though that's no help tp the customers.  As to allowing customers to buy their own modem, there's more to that than meets the eye although it is possible and, with a different support model, is reasonable if the choice is limited to something manageable for support purposes.

Likewise, they are fully aware of the poor performance and reputation of their offshore customer support - but they don't do anything about that.  [SEPH]: Yep.  And I wish a pox upon them for their pig-headedness in this regard.

<SNIP>

VM are in a position of continuing net gain in customer numbers, and in many places they have a struggle to serve the traffic they already have, there simply is no commercial case to do anything to improve their customer image, and whilst the D3.1 offer will be premium priced, I'll be very surprised if the hub is a premium product.  In fact, I'll go better than that - if the D3.1 hub is a premium product (by which I mean decent, reliable modem, fast, full functioning interface capable of properly managing connections, with strong, reliable wifi capable of mesh operation, the lowest latency we can expect via DOCSIS, and automated diagnostics communicated to the networks team) then I WILL EAT ONE.  I'm sure you'll agree that VM/LG will do for the next hub what they've always done - nail down a minimal specification based on one of Hitron or Arris' cheaper efforts, cut every feasible corner, repackage in a custom casing, aiming for an average price below thirty quid, leading to a really mediocre affair that delights nobody?  [SEPH]: I share your view here.  I do think (but don't know) that the Hub 3.1 will have Mesh wireless - because the competition does.  Modem mode will, as before, be the answer for people who rely on Broadband.

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[fizzyade]

I’d even pay a premium over us retail for a proper modem.  Take my money now VM.

[ShadowOfDeth69]

@fizzyade Come on mate, don't say that. Don't be a sucker. Paying a premium for equipment that works properly? Come on now. Don't be silly.

[fizzyade]

Sadly it would be the only way I could ever see them allowing a specific third party modem into their network.

[Andrew-G]

"I’d even pay a premium over us retail for a proper modem.  Take my money now VM."

They ARE taking your money now, and mine, and everybody else's.  And that's the problem - that even amongst us Hub 3 whiners, too few are cancelling our contracts and taking our business elsewhere.

And as a personal opinion, I suspect that even in some parallel universe where every Hub 3 Hater* cancelled their contract, it still wouldn't be big enough numbers for Vermin Media to give a flying wotsit.  If they're signing up a net 3,000 new punters a week (that's after taking away cancellations), they won't even notice, other than that there will be less moaning in the forums..  

* Message for the Forum team, I'm sure I've earned my Hub 3 Hater badge, but its not showing up?  Could somebody look into this and get it fixed, thanks.

[viper]

I cancelled after being a virgin customer for 9 years, been on the superhub 3 for about 3 months before I realised the issues. BT are connecting my new line on Friday. Bye virgin, I'll be posting your POS hub back to you via express courier. 

[francisuk1989]

Is anyone fancing this issue within there hub 3.0? I have had two engineers come out to my property, The first technician told me there nothing they can do and checked if the area has any issues and there wasnt, Now the second engineer come today and replaced my hub 3.0 but the same issue keep happening! http://community.virginmedia.com/t5/Networking-and-WiFi/broadband-constantly-dropping-in-and-out-fin...

Hub 3.0 FW is 9.1.116V

Finchley CMTS

[tonycv51]

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@francisuk1989wrote:

Is anyone fancing this issue within there hub 3.0? I have had two engineers come out to my property, The first technician told me there nothing they can do and checked if the area has any issues and there wasnt, Now the second engineer come today and replaced my hub 3.0 but the same issue keep happening! http://community.virginmedia.com/t5/Networking-and-WiFi/broadband-constantly-dropping-in-and-out-fin...

Hub 3.0 FW is 9.1.116V

Finchley CMTS

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in some respects your BQM is classic SH3 - however if you look at mine the whilst the yellow might be similar, your blue spikes and red indicate another problem with either the network in your area or your hub, whereas mine show an OK connection but with latency spikes caused by puma 6 flaw