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]

Hopefully they're announcing the end of Puma 6 production so new modems will have to use something else.

[Adduxi]

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@cje85 wrote:

Hopefully they're announcing the end of Puma 6 production so new modems will have to use something else.

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AFAIK, Compal have already started production of their next Modem using Broadcom chipsets.

Whatever happens the Hub 3, in my opinion,will never really be fixed. From what I can gather the Puma 6 cannot handle the load, so no amount of firmware will fix that ?

Anyway, time will tell .....  

[shanematthews]

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@dcookster wrote:

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@shanematthews wrote:

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@qpop wrote:

Had a thoroughly uninspiring call with the CEO complaints team today. The assigned agent hadn't got round to ringing me yet, despite the complaint being acknowledged a week ago, so I called their switchboard and asked to be put through.

I was told:

• No replenishing of SH2AC stocks
• Areas are running out and they don't know what stock levels are like, but he sees there was a 2AC requested and a 3 sent, so he guesses no 2ACs in my area
• No way of getting a 2AC from another area
• He still thinks there is no problem with high latency, as they make no latency promises
• As there is no "fault", there is no point in escalation to second-line support
• No acknowledgement of the issues "this is the first I've heard about it"
• A suggestion that my best bet was to wait until a "technical wiz" from the forums told me how to fix it with "port forwarding or something"
• A tacit suggestion that Virgin may help fund the cost of my own router if it was better in modem mode (I said it is). I mentioned  I use a Netgear R7000 which is currently selling on Amazon for £120 and his response was "well you can buy a router from Argos for £20 so that is what we would offer".
• Finally an appointment made with a local engineer who "might have a 2AC on board", but no way of asking in advance or asking the engineer to call and make sure.

Overall a shocking level of customer relationship handling from the most senior complaints team in the business - it really does concern me that people in such key positions can be both technically incapable and poor at dealing with customer complaints.

I now have an engineer's appointment next Friday afternoon...I am not holding out much hope...

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Having a router is unlikely to help too much as from what i understand the issue is with the modem side of the hub3 not the router side, he is also correct that residential services do not include any kind of latency SLA, and infact not much of an SLA at all, as such there technically isn't a "fault" that they can fix, and expecting them to cover even part of the cost of a £120 router is silly, especially when it won't solve the issue in the first place

Hopefully you'll get lucky with the tech having a suitable replacement, if not then you're pretty much stuck with it and the contract won't really allow for an easy cancellation as latency was never part of the deal and aslong as the speeds are being provided they aren't in breech so you would still be liable for early termination etc unless you could get the CEO's team to agree to waive it, won't actually fix the issue though 😛

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All well and good but don't Market a Gamer package when latency is a key driver of performance.  Like promoting a Gaming PC with a Pentium 2 and onboard Graphics.

Trading standards should take a look at Vivid 200 Gamer!

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Trading standards won't do anything, your contract carries no guarantee of latency, and not all games require low latency to work, you'll lose that battle pretty quickly

[eddiechatburn]

Well, that was a bust.

Surprise, but it was another SH3 that arrived.

Called again, couldn't get put through to 2nd line support! Told I have packet loss on one of my upstream channels causing the latency, so engineer on his way out on Saturday.

😞

[itinfocus]

Intel has now admitted that the Puma 6 has a serious DoS issue,

Details will be published under this CVE

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=2017-5693

Will Virgin now take this issue seriously?

[Rowethren]

Nope because they don't really care as long as they get the moniez!

[cje85]

In the short term there's not much they can do, the supply of SuperHub 2ACs has run dry and there is not yet a Hub 4. They could allow customers to use their own modem from an approved list, but very few will do that. I think the best we can hope for is a Hub 4 in the near future, based on one of Arris' new products which use Broadcom instead of an Intel chipset.

[ItsCraigo]

I've still got my 2ac, going to get VM to reactive it.

[itinfocus]

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@cje85 wrote:

In the short term there's not much they can do, the supply of SuperHub 2ACs has run dry and there is not yet a Hub 4. They could allow customers to use their own modem from an approved list, but very few will do that. I think the best we can hope for is a Hub 4 in the near future, based on one of Arris' new products which use Broadcom instead of an Intel chipset.

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In the short term you are probably correct. It's just such a shame that Virgin have completely ignored, denied, obfuscated and well generally lived up to there own customer service reputation for the past several months.

Serious issues were reported by the beta testers. Regular users have been complaining since the introduction of the Hub 3.0. 

More advanced users have since undeniably demonstrated the significant flaws in this modem.

Are we supposed to now just accept that any customer with a hub 3 can be denied ANY web access for an indeterminate amount of time?

Virgin have had the warnings, time and good will of customers warning them that this is not fit for over six months. The day the CVE is published cannot be accepted as day one of the fix. The six month head start they would have had if they took customer service seriously was long enough to have at least significantly started the process of finding an alternative.

Now quite honestly I don't care what brand damage this causes, the solution is simple. Either provide or allow the connection of another, customer sourced modem. I mean seriously how hard can it be for virgin to add an existing hub 2 from eBay to be added to a customers account? Validate any of the known Broadcom modems? Even tell us that this unit will be the Hub 4 you can self supply and we will eventually brand the living daylights out of it later?

We are all customers, we have ongoing and about to get much worse issues. It's not unreasonable to expect the company that many of us pay significant amounts of money to each month to look for a way of fixing this rather than accept just waiting on the next planned update.

[shanematthews]

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@itinfocus wrote:

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@cje85 wrote:

In the short term there's not much they can do, the supply of SuperHub 2ACs has run dry and there is not yet a Hub 4. They could allow customers to use their own modem from an approved list, but very few will do that. I think the best we can hope for is a Hub 4 in the near future, based on one of Arris' new products which use Broadcom instead of an Intel chipset.

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In the short term you are probably correct. It's just such a shame that Virgin have completely ignored, denied, obfuscated and well generally lived up to there own customer service reputation for the past several months.

Serious issues were reported by the beta testers. Regular users have been complaining since the introduction of the Hub 3.0. 

More advanced users have since undeniably demonstrated the significant flaws in this modem.

Are we supposed to now just accept that any customer with a hub 3 can be denied ANY web access for an indeterminate amount of time?

Virgin have had the warnings, time and good will of customers warning them that this is not fit for over six months. The day the CVE is published cannot be accepted as day one of the fix. The six month head start they would have had if they took customer service seriously was long enough to have at least significantly started the process of finding an alternative.

Now quite honestly I don't care what brand damage this causes, the solution is simple. Either provide or allow the connection of another, customer sourced modem. I mean seriously how hard can it be for virgin to add an existing hub 2 from eBay to be added to a customers account? Validate any of the known Broadcom modems? Even tell us that this unit will be the Hub 4 you can self supply and we will eventually brand the living daylights out of it later?

We are all customers, we have ongoing and about to get much worse issues. It's not unreasonable to expect the company that many of us pay significant amounts of money to each month to look for a way of fixing this rather than accept just waiting on the next planned update.

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They are unlikely to change their stance on non-VM kit on the network regardless of the CVE, it might speed up the hub4 process a little but probably not by any meaningful difference, it would take a massive wide scale DDoS attack for any real changes to be made sadly and thats not likely to happen, in this instance all you can really do is wait unless you plan on jumping ship to another ISP