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]

[Groka]

Wait, Vivid 200 isn't an option anymore? How did you manage to get the 300 increase as well as a lower price? The reason I ask is, I'm on Vivid 200 (albeit on a Superhub 2AC) and wouldn't mind taking advantage of this (seeing as VM have been fleecing me with price increases and a lacklustre service for the good part of 12 months).

[philjohn]

If you've done your research on the Vodafone router, you'll know that it's rubbish, and you need to put your own in place and phone up customer service to get the PPPoE username and password.

And despite their policy now being that you can have it (for the longest time they refused and you had to use their kit) most of the support staff don't know this and will kick up a stink, or so I've heard.

So - your best bet is grabbing an OpenReach Huawei hg612 off ebay and sticking a decent wireless router behind it.

[richto]

My VM connection looked like that before the firmware update, with constant latency peaks at about 140ms. After the update there are about half the number of peaks and they are at about 100ms. However thats still pretty awful and a long way from fixed. Doesnt look anything like your BT. However fibre here is only circa 80Mbits max and I do maxout my 200Mbits VM connection regularly via bit torrent, etc.

[richto]

Also the UDP packet loss problems seem to have improved. A check using the GRC DNS checker shows only a few drops versus 1-5% previously.

Now:

Before update:

[nickking]

Groka, VIVID 200 is an option, VIVID 200 Gamer isn't.

I just spoke to someone on live chat about it, they confirmed VIVID 200 Gamer didn't exist and moved me on to VIVID 350 and advised it was £4.50 cheaper a month.

[dcookster]

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I dispute what Shane says - though only a legal case would show who's right.

The contract is not allowed to trump the advertising you that induced the purchase of VM's service.  http://www.virginmedia.com/shop/broadband/vivid-gamer.html comes to mind.

If they knowlingly put out a flawed device that defeats their claim " It’s broadband for gamers . For the hardcore. For the best. ", then they are liable at law, imo.   It needs testing - a bluff might do it like getting a solicitor to write to them. 

I'll bet there hasn't been a word from VM as to what the new firmware actually cures.  Because it cures nothing - it has merely shuffled the deckchairs.

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The "broadband" is perfectly suitable for gaming on, the hub3 isn't, you also need to define what is or isn't required as games come in many shapes and sizes, the hub3 will have zero to minimal effect on anything not latency intensive, the likes of grand strategy or casual games, most MMO's also aren't going to be impacted by the tiny microstutters, hell i know an MMO that will still work perfectly fine over an actual dialup connection, so i would be expecting the outcome of that to not go in your favour, especially considering most judges likely aren't gamers so won't understand the issue, the advertising doesn't make any mention of latency either so again ,thats not false advertising

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I have no idea what planet you spend your days on.  The adverts are very clear in their wording about how perfect the Hub 3 is for hard core gamers - and with that comes the obvious implication of meeting latency requirements.  VM know in advance of the latency flaws in the Hub 3 and they are thus knowingly making false claims.  Poor latency due to congestion, etc, is what the contract covers in the same way as speed.

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Show me something that explicitly says the hub 3 is great for "hardcore" gaming latency, go on, i'll wait 😛

Because i can guarantee you it doesn't, you can be as pedantic as you want about it but bear in mind legal will have signed off on the advertising and i would expect them to know a little about that, unless you're hiding your law degrees from us, gaming comes in many flavours and quite a lot of it won't be affected by slightly higher latency

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You are the pedantic one.  You insert the word "latency" but ignore its implicit presence when VM state (in the link I gave):

VIVID 300 is your secret weapon. It’s the fastest widely available download speed in the UK#. It’s up to 20Mbps upload speed for flawless streaming and sharing. It’s fibre broadband without traffic management . It’s broadband for gamers . For the hardcore. For the best. 

The VM T&Cs make no mention of your pedantic word "latency".  The relevant clause states:

Due to the nature of the Internet, we cannot guarantee specific levels of performance for Internet access.

If it's the Internet that's busy, then the clause applies.  If it's a pre-known defect in a VM supplied device that adversely affects the gaming experience (in whatever cases), then then merchantability/quality legislation applies to the VM service.  I'd like to hear from anyone who agrees with you.

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It specifically states "Vivid 300" and the vivid 300 IS suitable for that and DOES meet those requirements, the problem is that getting the vivid 300 requires a hub3 or above, issue is there is no "above" at present so its hub3 or bust, your quote makes zero mention of the hub3 specifically, and if you actually genuinely thought you would win in court you would have done it or someone else would have done it which means that at some point the regulators and a legal expert have weighed in on this and nobody has found these adverts to be incorrect, sure its scummy because the hub3 is the only option for the vivid 300 "at present" but that doesn't change that the service the hub connects to DOES meet all of the things they advertised

And protip, that clause applies all of the time as latency can never be guaranteed at any time of the day or under anything other than laboratory conditions, so, you are welcome to "try" and take this up with the ASA, ofcom and your local lawyers but my money is on the advertising itself not being misleading but i'm happy for you to PROVE me wrong 😛

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Now you're beginning to worry me about the state of your senses.   You are being pedantic by confining your observation to the specific quot.  However, the link I provided, which is highly relevant states (including the Hub 3): 

Why VIVID 300 is best for gamers 

Whether you’re owning the competition in your favourite FPS  or exploring expansive worlds across MMORPGs and games like Destiny 2 ,VIVID 300 is equipped to take your online gaming to the next level on console, on PC, and on everything in between.

• Totally unlimited for unlimited downloads and streaming
• Faster upload speeds (Up to 20Mbps), for sharing wins with friends and followers
• No traffic management for non-stop online action
• Ultrafast download speeds of up to 300Mbps
• Our best ever WiFi hub (Hub 3.0), for improved wireless performance

Get a grip.  I find it strange to be in conflict with you!

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@nickkingwrote:
Good morning all,

I'd like to share with you an excerpt from a letter I received from the Virgin Media complaints department after contacting the CEO's office regarding the Hub 3.0.

"I am sincerely sorry for the overall experience you have described on the account. I appreciate the frustration this has caused you. I would like to confirm that Virgin Media will not be changing the super hub 3 based on the issues you have raised. The super hub 3 has been passed as fit for purpose to which it provides broadband connection on a residential contract. The equipment has been passed fit and satisfactory for purpose by our regulators"

They also go on to remind me our contract ends in August, a sort of if you aren't happy then leave statement if ever there was one.

Obviously I've replied on how disgusted I am with their response and lack of understanding of the issue.

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Oh they "understand" the issue, but technically speaking he is correct, the hub 3 DOES meet the requirements laid down in the contract you agreed to, latency is not guaranteed and the hub 3 is more than able to provide a connection at the advertised speeds so it is "fit for purpose", sure it doens't provide the lowest latency but until thats actually part of a regulation or advertised as being within a certain range, neither of which is ever going to happen, then they aren't going to spend a fortune replacing the device with something else

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You'll never win an argument with an idiot. Better to ignore than engage.

[Andrew-G]

OI! TRIM YOUR ***** POSTS!  ALL OF YOU!

And especially YOU shanematthews, do please stop shilling.

[Rich2005]

Being lazy here, but to save myself reading back hundreds of pages of messages, can someone just let me know:

a) If there's finally a firmware fix for the SH3 that resolves (or at least significantly improves) the latency issue

b) If it does exist, how does one actually get it, or is it just a case of praying to the packet gods and hoping it arrives before I depart this mortal coil

Thanks

[Sephiroth]

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@Rich2005wrote:

Being lazy here, but to save myself reading back hundreds of pages of messages, can someone just let me know:

a) If there's finally a firmware fix for the SH3 that resolves (or at least significantly improves) the latency issue

b) If it does exist, how does one actually get it, or is it just a case of praying to the packet gods and hoping it arrives before I depart this mortal coil

Thanks

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.... and indeed across different threads on the subject.

1/
The PUMA 6 CPU is of low spec (single core) and is thus heavily utilised because all of the traffic on a segment hits it and is filtered through by your own security key generated when the modem is switched on.

2/
The processor and associated memory is so overloaded that every 20 to 30 seconds it does an emergency interrupt to clear its cache and so on. This will stop some games in their tracks.

3/
Every second, the TBB BQM system, for those subscribing, makes an ICMP call (you can Google that) to your router. This call has to be handled hitherto by the Puma 6 chip.

4/
The yellow portion of the graph is very misleading. It is a maximum latency measure. So that in any 30 second period, you might get 25 of those ICMP pings being serviced in around 10 to 20 milliseconds; when the Puma 6 chip interrupts, the ping round trip time rises and it is this maximum that is recorded in the BQM as the yellow area. The blue average area remains relatively unpurturbed.

5/
The new firmware displaces processing of ICMP packets from the Puma 6 into the AR9382 chip. A clever dodge which shows a nice BQM graph, but isn't even the tip of the iceberg when it comes to load that remains on the Puma 6.

[rio_w]

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@philjohnwrote:

If you've done your research on the Vodafone router, you'll know that it's rubbish, and you need to put your own in place and phone up customer service to get the PPPoE username and password.

And despite their policy now being that you can have it (for the longest time they refused and you had to use their kit) most of the support staff don't know this and will kick up a stink, or so I've heard.

So - your best bet is grabbing an OpenReach Huawei hg612 off ebay and sticking a decent wireless router behind it.

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I always use my own router, and the option is there, I was stuck with using VM hardware which is the only time I’ve used supplied hardware