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Hub 3 / Compal CH7465-LG (TG2492LG) and CGNV4 Latency Cause

Datalink
Up to speed

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]

4,478 REPLIES 4,478


@shanematthews wrote:
Well it depends how you acquired this unopened SH2, its not likely to have been registered to your account but will have been registered to another at some point, sale/transfer of hubs isn't allowed as VM are the owners of the equipment

It appears you're missing the forest for the trees. That policy is set by VM and they have full control over it and how and if it's enforced - so not sure why you simply repeating the party line. There is no regulatory requirement to have this policy. In other words it's absolutely their fault.

In the US even the most hated cable companies (eg Comcast) allow both used equipment and 3rd party on their networks.


@Butler85 wrote:
With regards to shipping out of the older hubs, people just need to get passed the idea that this is an alternative. If you have one from prior to the upgrade and your config supports it (i.e. not Vivid 300), then you're good to go. Otherwise, I'm afraid you're stuck waiting

Pretty sure most people aren't under this illusion. However, as I mentioned a few posts back, happy to give some of my own time and energy pushing this issue for my benefit and that of the tribe.

In case it wasn't clear it's a win-win scenario for VM and users. Those care about the issue (ie people in this thread) would have a solution. Plenty of SH2's to go around. The issue is not lack of supply.

For the record, I'm also fully supportive of efforts to find a technical fix. However, after following the DSLReports thread, I'm less optimistic here than some that Intel will be able to fully fix it in a firmware update. It could be half baked when it arrives, and who knows when or if that day comes.


@astrohominis wrote:

@Butler85 wrote:
With regards to shipping out of the older hubs, people just need to get passed the idea that this is an alternative. If you have one from prior to the upgrade and your config supports it (i.e. not Vivid 300), then you're good to go. Otherwise, I'm afraid you're stuck waiting

Pretty sure most people aren't under this illusion. However, as I mentioned a few posts back, happy to give some of my own time and energy pushing this issue for my benefit and that of the tribe.


If you read through the thread there are several cases of people crossing fingers and requesting virgin send out a hub 2/2ac, only to be upset when a hub 3 arrived in the post. Some people did this several times in fact.

I can assure you, that you could put a lot of time in effort into trying to get Virgin to provision used modems and it will go absolutely nowhere. If VM have stockpile of unused modems, then by all means, they could send those out and activate them without a problem. We already know that configs upto and including the Vivid 200 Gamer will provision to a 2/2ac, but anything used is just a no go.

Please note, these '2nd hand' modems shouldn't even be out for sale in the first place (We don't own the modems, we rent them)

--------------------------------------------------------
Look behind you, a three-headed monkey


Butler85 wrote:Please note, these '2nd hand' modems shouldn't even be out for sale in the first place (We don't own the modems, we rent them)

As explained there is no moral or regulatory law that governs that statement. VM is fully in control of the policy of how used equipment whether rented, owned or leased, gets used on their network.

It would seem VM are not interested in the time and expense of recovering old SH2's from users. That's again purely a business decision.


@astrohominis wrote:

Butler85 wrote:Please note, these '2nd hand' modems shouldn't even be out for sale in the first place (We don't own the modems, we rent them)

As explained there is no moral or regulatory law that governs that statement. VM is fully in control of the policy of how used equipment whether rented, owned or leased, gets used on their network.

It would seem VM are not interested in the time and expense of recovering old SH2's from users. That's again purely a business decision.


And assuming they wrote out to people now asking them to return older hubs. Aside from the costs in doing that analysis to attempt to provide such a list, recovering the hardware, the none responses, the ones that have already disposed of them, the team to refurbish and test the product to ensure safety standards, the sending it back out, the changes required at a network level... it just seems like a huge walk in the park. How did I miss such a thing? 

Let's stop living in the past here, the hub 3 is here to stay until a future hub replaces it and start concentrating our efforts on getting Virgin to at least roll-out the current firmware patch available.

 

--------------------------------------------------------
Look behind you, a three-headed monkey


@Butler85 wrote:
Let's stop living in the past here, the hub 3 is here to stay until a future hub replaces it and start concentrating our efforts on getting Virgin to at least roll-out the current firmware patch available.

 


Maybe it's an old router, but it works. If we talking about living in various places, maybe you should try reality?

To be clear, there is currently no firmware patch that fixes the issue. Not from Virgin, Intel or anyone else overseas.

There's also a 50/50 chance there may never be a fix given the hardware constraints. What does exist is a patch that improves ICMP traffic. Which is utterly useless unless you love doing traceroute's and pings for a living. Smiley Very Happy

Are you trying to win points for irony? The person hell bent on trying to get virgin to start re-issuing old modems (because we know they don't have stock of the older modems) ignoring any points I've made in my previous post tells me to live in reality. Which reality is this and do I need a flux capacitor to get there?

Secondly, find a point where I have claimed it is fixed. Improved, yes, fixed no.

50/50... did you pull those figures from that reality you talk about? We'd love to hear the technical insight taken to produce such bold predictions.

And lastly, please keep up if you're going to at least pretend to participate. ICMP was the first part of a fix done a long time ago. There has since been a second fix produces by Arris, before they went radio silent (one can assume because of the legal side of this tail), that does more than just ICMP. I know for one that fixes DNS, but what else I'm unsure because patch notes have been somewhere between vague and Latin, but those on the patch (again, including the Hittron device used by virgin's business side) show a better result on DSLReports own Puma 6 test.

That test I 'can I be clear' is not an ICMP test.


--------------------------------------------------------
Look behind you, a three-headed monkey

I have disconnect issues over a wired connection as well as high ping making it impossible to game. I never had that on SH2. Virgin technical support have replaced the router with no improvement and all they can say is that it is my equipment. The same desktop PC that had be flawless before the change. I told the guy about the threads on this forum and he said that in all his time that he had only had one other call on this issue. I would call that a denial.
When I got back from work on the day when the engineer was here installing my TV package he had just swapped over the router and had my SH2 beside him. Upon hearing my concerns and saying that I wanted the SH2 back he said it was too late as the new router had been registered. So it is not a question of lack of hardware but rather lack of will. I'm on 100 mbs by the way.
I see the SH2 on Ebay. Why is it so impossible to get one of these working? We are not asking anyone to walk on water here.
This is a scandal.


@Butler85 wrote:
Secondly, find a point where I have claimed it is fixed. Improved, yes, fixed no.


Maybe you can explain how advocating for a firmware update that doesn't fix the issue, whilst throwing shade on alternate solutions is a good way to go?

There's more than one way to bake a cake. xoxo


@astrohominis wrote:

@shanematthews wrote:
Well it depends how you acquired this unopened SH2, its not likely to have been registered to your account but will have been registered to another at some point, sale/transfer of hubs isn't allowed as VM are the owners of the equipment

It appears you're missing the forest for the trees. That policy is set by VM and they have full control over it and how and if it's enforced - so not sure why you simply repeating the party line. There is no regulatory requirement to have this policy. In other words it's absolutely their fault.

In the US even the most hated cable companies (eg Comcast) allow both used equipment and 3rd party on their networks.


See here's the important part, there are multiple cable providers in the US, the same way there are multiple ADSL providers, which do allow you to use any 3rd party modem, here VM have the monopoly on the cable market, they set the rules that allow only VM authorised kit to be used, once a hub has been removed from the system its called as unauthorised, generally speaking its unlikely VM even bother keeping them as most of them will have been refurbed multiple times and will be at the stage that they are beyond repair and just binned, its not viable to keep reusing really old kit, it causes more headaches than it is worth, hence them being phased out and replaced, VM aren't going to suddenly decide to allow 3rd party modems on their network, its way too much work for them, they activate devices based on their MAC address and this would mean having to add support for multiple providers worth of MAC's and then enabling an ancient system to update them, now, what happens if one of the types of modem ends up with a massive security flaw, VM won't be able to push a firmware update for it because you're using a 3rd party modem, you choosing not to update your modems firmware could end up causing issues on the network

Yes VM set the policies, but they do have valid reasons for it, they are also unlikely to spend time and money testing and re-adding old discarded hub 2's back on their network when they have a stock of better condition hub 3's, yes the hub 3 has its own flaws, but at the end of the day we don't have the power to do anything about it and VM won't change their policy, there is no regulation that states they have to allow 3rd party devices on to THEIR network, and protecting their network hardly counts as "their fault"