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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

Im going to leave this here for all your viewing make a decision and change provider if your not getting what your paying for!

 

Hub3 in Router Mode

large.png

small.png

Hub 2AC in Modem mode with Linksys WRT1900ACS

Hub 2AC Modem Mode Linksys Wrt1900acs.png

Ignore the RED its me setting up the BQMIgnore the RED its me setting up the BQM

Speeds are Good!Speeds are Good!

Now Tv/Sky Broadband Super Fibre package

Now TV Broadband.png

Now TV -Sky Broadband BQM.png

wotusaw
Superfast

I cannot see it?

Have you been sensored?

Thought I was living in the UK, not North Korea.

It would be very interesting to see this information.

Anonymous
Not applicable

Mods have to approve images for some odd reason.

SCA1972
Very Insightful Person
Very Insightful Person

@Anonymous wrote:

Mods have to approve images for some odd reason.


The odd reason is to prevent spamming of the boards with unsavory images that may cause offence or to prevent the unwary revealing personal info like their IP or MAC address in an image.

I have approved the images so they should be visible to all now.

______________________
Scott

Disclaimer - I don't work for Virgin Media. I'm just another VM user trying to help out so my answers may be wrong Smiley Happy If my answer solves your problem please mark it as helpful as it may help others
My setup: Vivid 200 Optical fibre with Hub 3 in modem mode connected to a Netgear R7000 router. Telewest/VM user since 2001.

I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more

Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks

PhilMull
On our wavelength

The problem is that although this clearly displays the problem that we are experiencing Virgin just won't care because not enough people are complaining. This is my second hub 3 and it still disconnects every few minutes over lan cable. I've had to buy a third party wireless adapter and I still get high ping rate at regular intervals.

I asked to go back to superhub 2 but they said it's impossible so now I'm stuck for twelve months with this rubbish.

 

wotusaw
Superfast

I think they would care if there was someone who was a real competition to them. 

At the moment they have a monopoly service which must contradict fair trading standards, surely. It just seems very odd to me.

Who else offers 200mb/300mb and tv/phone etc and has such an extensive network.

BT Infinity 2 is only 76mb. Sky is the same at 76mb.

Why have Virgin been allowed to get so far ahead of everyone else?

I know there are 'hyperfast' companies but they don't have the networks and they don't offer tv/phone.

So what gives here?


@wotusaw wrote:

I think they would care if there was someone who was a real competition to them. 

At the moment they have a monopoly service which must contradict fair trading standards, surely. It just seems very odd to me.

Who else offers 200mb/300mb and tv/phone etc and has such an extensive network.

BT Infinity 2 is only 76mb. Sky is the same at 76mb.

Why have Virgin been allowed to get so far ahead of everyone else?

I know there are 'hyperfast' companies but they don't have the networks and they don't offer tv/phone.

So what gives here?


What???

So you're saying that Virgin Media should do nothing to improve the quality and speed of their service, because openreach (in reality) have not yet provided the infrastructure for other services to do the same. And what does any of this have to do with a monopoly? Most if not all VM area will also serve broadband services, the speed scenario is not a requirement. 

To break this up a little and stop talking a walk down conspiracy lane... the hub 3 runs a puma 6 chipset. The puma 6 chipset, which is used worldwide has an issue with it which is yet to be completely fixed via firmware patching or anything other method. There is a current update firmware that greatly improves that, which has of yet, not yet been released to the hub 3. I would amazed if VM/LG aren't working with the hardware providers to modify the firmware patch to a usable state for VM, which will then go through the usual testing scenarios (although probably released regardless of feedback). 

The fault of VM at this point is the "if we don't mention it, it's not a fault we have to deal with immediately" scenario. You won't find anywhere that's not an external source that says VM are working on a fix for this, which in my opinion is poor. A simple, we are aware of this, we are looking into this and we hope to have a test out by the end of June would have been good, but maybe from there slipping dates of the upgrades they would rather not get in that situation again.

Now hopefully we can get back onto proper discussions and stop making posts that any of those TBB graphs are a surprise to anyone this far into the process.

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


@wotusaw wrote:

I think they would care if there was someone who was a real competition to them. 

At the moment they have a monopoly service which must contradict fair trading standards, surely. It just seems very odd to me.

Who else offers 200mb/300mb and tv/phone etc and has such an extensive network.

BT Infinity 2 is only 76mb. Sky is the same at 76mb.

Why have Virgin been allowed to get so far ahead of everyone else?

I know there are 'hyperfast' companies but they don't have the networks and they don't offer tv/phone.

So what gives here?


VM isn't preventing cable companies from providing service, there are a number of gigabit providers using their own cable networks, but thats the catch, they have to lay their own cables and build their own network, its not the same as ADSL where a phone line is required and which caused changes to be made regarding BT's monopoly on the phone network, VM and the names the company was known under before all paid and laid that cable themselves, they don't use BT's network except for "national" customers, its not a monopoly in the sense that trading standards would care, BT can provide to anywhere VM can and can infact service more of he country than VM's cable offerings, they are for all intents and purposes the smaller of the big 2, even sky can service more areas than VM, anywhere you live you have alternatives for TV and phone which means by definition its not a monopoly

wotusaw
Superfast

Me!

Responsible for a conspiracy theory!

The mere thought is intolerable!Smiley Mad

However thanks for the information...and smackdown, ouch!.Robot Embarassed


@wotusaw wrote:

Me!

Responsible for a conspiracy theory!

The mere thought is intolerable!Smiley Mad

However thanks for the information...and smackdown, ouch!.Robot Embarassed


Glad the information was of use and hopefully not too brash. Just want to keep this thread (if possible) somewhat on track in terms of updates we can get hold of, albeit from external sources and not VM themselves of course *ahem*

 

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