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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


@Tolaris wrote:

Update: replacement of SuperHub 3 with 2ac failed. Followed automated provisioning instructions, new 2ac modem never joined network. Called tech support, who did their best to help. But during conversation it was clear they misunderstood and were trying to "upgrade me from 2ac to 3", the opposite of what I intended. Eventually we gave up and used the SuperHub 3 again, while scheduling an installer to come later in Feb to help.

This is unacceptable,Virgin. You're using your tech support people to cover for your poor engineering practices (here I refer to the clear lack of hardware testing).


I hate to be the bearer of terrible news but as of the 30th of april VM are looking to FORCE all customers to use a hub3 or to not have internet at all https://keepup.virginmedia.com/hubupgrade see this link

 

What happens if I don’t swap my old bit of broadband kit?

If you do not swap your old bit of broadband kit it will soon stop working so you will not be able to enjoy our fastest broadband speeds and wireless connectivity – and we don’t want you to be stuck without internet. So to make sure there’s no interruption to your service, we’ve made upgrading to a Hub 3.0 free and easy.

If you have other services with us, like telephone or TV, and you do not upgrade your old bit of broadband kit, you will lose your broadband service and we will remove this from your account and amend your monthly bill.

If you only have Broadband services with us and you do not upgrade your old bit of broadband kit, we’ll close your account and send you your final bill.

When do I need to order by?

If you do not upgrade your old broadband kit with a new Hub 3.0 by 30th April 2017 it will stop working. We want to make sure your service isn't interrupted - so don't leave it to the last minute! In fact, why not order it now?

SCA1972
Very Insightful Person
Very Insightful Person

@shanematthews wrote:

I hate to be the bearer of terrible news but as of the 30th of april VM are looking to FORCE all customers to use a hub3 or to not have internet at all https://keepup.virginmedia.com/hubupgrade see this link

 

 Fake news! Smiley Tongue

That link is only for users with old standalone modems that predate the superhubs.  They are being contacted by VM and pointed at that page.

______________________
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 Superhub 2 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

Is that what they mean by "old bit of broadband kit"? (does that not include SH2/SH?)


@SCA1972 wrote:

@shanematthews wrote:

I hate to be the bearer of terrible news but as of the 30th of april VM are looking to FORCE all customers to use a hub3 or to not have internet at all https://keepup.virginmedia.com/hubupgrade see this link

 

 Fake news! Smiley Tongue

That link is only for users with old standalone modems that predate the superhubs.  They are being contacted by VM and pointed at that page.

______________________
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 Superhub 2 in modem mode connected to a Netgear R7000 router. Telewest/VM user since 2001.


That page sadly does not state that at all and that page does specifically state "upgrade your hub" which implies you already have one of the hubs

SCA1972
Very Insightful Person
Very Insightful Person

@shanematthews wrote:

That page sadly does not state that at all and that page does specifically state "upgrade your hub" which implies you already have one of the hubs


The poor wording on that page was pointed out by @MUD_Wizard back in August last year and he did predict that it was very likely to cause confusion.  He was right Smiley Happy

There is more about it from @BenMcr on another forum here:

http://www.cableforum.co.uk/board/showthread.php?t=33703504

______________________
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 Superhub 2 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

So - not so simple for me - I tried exactly the same approach and received the following responses:

 - finally get through to technical support - and they tell me it is impossible for technical support to ship out a modem downgrade

- I ask for a supervisor who tells me the same thing (15 mins later!) - and then redirects me to Customer Support who can do this.

- after another lengthy delay - I have the same discussion with Customer Support -who tell me that it isn't possible for them to ship any modem at all - and this can only be done from Technical support

- they transfer me back to Technical Support - and I go through the same account questions again (4th time!) and receive the same answer that it isn't possible

- I escalate to "the floor supervisor" who re-assures me that it is impossible to ship me anything other than a Superhub 3 as "the system doesn't allow it". He also won't send an engineer out - "as there is no fault showing on the line" (easily fixed!). After a protracted and very circular argument where the supervisor says it is "impossible" to ship a Superhub 2ac to a Superhub 3 customer - and I respond that according to this forum - that is exactly what has been done.

- Eventually he compromises and requests a modem replacement - and (reportedly) includes a "special note" requesting a Superhub 2ac for me - and he effectively leaves it up to the dispatching team to make the decision on what I receive.

So - I'm now waiting to see what (if anything) I receive as a replacement. Either way (assuming I receive something) - Anyone want  a Superhub 3? Known to have this latency / jitter problem - lightly used - 1 previous owner 🙂

Total elapsed time was 73 minutes on the call speaking to 4 people in the end.


@gandalfmeister wrote:

 

So - I'm now waiting to see what (if anything) I receive as a replacement. Either way (assuming I receive something) - Anyone want  a Superhub 3? Known to have this latency / jitter problem - lightly used - 1 previous owner 🙂

Joking aside, be aware VM still own the Hub 3 and they'll want it back (they send you a return box). So not only would you be selling stolen property but you'd have to pay for the replacement too.

Btw, they'll probably send you another Hub 3. So you'll have two.

 

The smiley was intended to imply it was a joke! I am aware that VM own the device - but I already have 1x Superhub 1 that they didn't want back when they upgraded me to Superhub 3 so I'm not convinced they will ask for it back. If they do send another Superhub 3 - I won't even be installing it - I'll just send it back if they ask for it - or leave it in the box if they don't)

I have a superhub 1,2 and 3. Not once did they ask for it to be returned. Kept the Hub 3 for a few weeks and then just had my 2 reactivated with my Asus plugged back in.

SCA1972
Very Insightful Person
Very Insightful Person

@Sky_Lord wrote:
I have a superhub 1,2 and 3. Not once did they ask for it to be returned. Kept the Hub 3 for a few weeks and then just had my 2 reactivated with my Asus plugged back in.

VM are no longer asking for SH1 or SH2 back but they should have requested the return of any unused or replaced Hub 3.  If they haven't then it is an oversight which they may notice at some point in the future and request it back.

______________________
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 Superhub 2 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