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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

Hi, I discovered the issue about 1 week after I installed the router and signed a contract. I got a firm No when I asked them if I can get a different modem,perhaps hub2.Internet is still fine,I pay for 100mbit and get that,only issue is with gaming ,ping will jump +50ms every ~30seconds or so,not game breaking,but definitely noticeable.

Between the puma chipset latency issue and Virgin's firmware issue with Xbox Live can someone from VM please explain to me why I have just agreed to upgrade to Vivid 200 Gamer so paying more and agreed to a new 12 month contract in return for worst service, unable to use xbox live - I cannot even sign in on my 360 and I now have a worse modem that gives latency spikes over the superhub 2ac I had before.

And I am still expected to pay over £60 a month for this?

Glad my TV subscription is separately with a competitor I must say!


-Matt
BQM monitor:My Broadband Ping - Virgin Gig1

I called the pre-installation team after writing my previous post. I was advised that they are not aware of any issues and that they, being the front line of customer service, would have been told about it. So it would appear that they are just as in the dark as we are.

I am going to move ahead with my install, however the connection will be extensively tested at that point and each day and if there appears to be an issue, I will not hesitate to continuously get an engineer out to investigate and then cancel if the issue is not acknowledged or resolved within the 14 day cooling off period.  


@Chandoraa wrote:

I called the pre-installation team after writing my previous post. I was advised that they are not aware of any issues and that they, being the front line of customer service, would have been told about it. So it would appear that they are just as in the dark as we are.

Cough, yeah right. Every time you call they'll say that.

I am going to move ahead with my install, however the connection will be extensively tested at that point and each day and if there appears to be an issue, I will not hesitate to continuously get an engineer out to investigate and then cancel if the issue is not acknowledged or resolved within the 14 day cooling off period.  


It's worth spending some time getting the setup right, as sometimes installers don't get the power levels right or basics like that.

If you're not playing fast-paced shooters like CS:GO, Battlefield 1 etc you won't notice the latency spike issue.

It won't affect streaming, downloading, browsing or games that don't require consistently low latency.

You're much more likely to notice IF your area is over-utilised (nothing to do with this thread or the hub type), as that would impact all content usage during peak times only (4pm to midnight). That's easily testable by using this speed test over a gigabit wired ethernet connection and looking at the single threaded results: http://www.thinkbroadband.com/speedtest.html 

It isn't possible to find out if your area is over-utilised by calling Virgin anyway, so testing or asking your neighbours/checking the forum is your only option.

Good luck.

So here's an update on my SH3 latency complaint to VM HQ.

Had a call from a nervous sounding (!) person at VM complaints dept. The lowdown is that they are ordering me a Hub 2AC, and that should arrive by next Wednesday. He will call me again on Thursday once everything is up and running to discuss the promised discounts I was due the last two billing cycles but was never given.


@robbiekhan wrote:

So here's an update on my SH3 latency complaint to VM HQ.

Had a call from a nervous sounding (!) person at VM complaints dept. The lowdown is that they are ordering me a Hub 2AC, and that should arrive by next Wednesday. He will call me again on Thursday once everything is up and running to discuss the promised discounts I was due the last two billing cycles but was never given.

im about to cancel my contract, been paying for 300/20 but since the 19th of december only been getting 150 in the evening, vm said they wont do anything about it, so they can jog on, they aint getting any more money from me.

http://www.thinkbroadband.com/ping/share/6c7f9a9f20c4b3cac9edc401f62167c3.html

Just signed up to thank the people of this thread about the problematic SH3.  I was looking to sign up to the 200 gamer package this weekend to replace my current Plusnet FTTC (64/18 sync speed) as the VM prices had dropped for new customers.

 

I would have used the modem in modem only mode as I like to use my own router (r7000 currently) as the ISP modems/router that are sent out are sub par on FTTC (plusnet's hub one and sky's sagem 2504 (I was on the trial and this is what they provided at first)).

 

I will keep an eye on this thread and for now I will stick with PN (still in contract anyway) and see what the future holds.  For information purposes here is a TBQM and DSLreports speedtest and ping test to bbc.o.uk using MacBook Pro 2015 i5 8GB ram on 5Ghz wireless)

 

[url=http://www.thinkbroadband.com/ping/share/6d42fbc77b346a7375fe939611107b29-23-01-2017.html][img]http:...

[/url] [url=http://www.dslreports.com/speedtest/9524252][img]http://www.dslreports.com/speedtest/952...

PING bbc.co.uk (212.58.244.22): 56 data bytes
64 bytes from 212.58.244.22: icmp_seq=0 ttl=53 time=11.233 ms
64 bytes from 212.58.244.22: icmp_seq=1 ttl=53 time=10.836 ms
64 bytes from 212.58.244.22: icmp_seq=2 ttl=53 time=10.820 ms
64 bytes from 212.58.244.22: icmp_seq=3 ttl=53 time=10.649 ms
64 bytes from 212.58.244.22: icmp_seq=4 ttl=53 time=10.757 ms

robbiekhan
Up to speed

^^^ Your BQM graph reflects the tool not being able to ping your router/hub. I assume you have turned on the option to respond to ping requests? because if you were getting 100% packet loss, then you wouldn't have any internet at all.

 

OK so I have had the SH2ac installed )replaced the SH3 as noted in earlier replies) and am on 200Mb Gamer. No problems and the latency spike problem is gone as expected.

Happy with that, although over utilisation still exists during peak times in this area, so still a ways to go for VM to sort that issue out their end.

Now to await the callback from the complaints handler next week to discuss the false promises made by telephone staff during this whole ordeal...

@robbiekhan : you will be waiting a long time for them to sort out the over-utilisation problem. Nice to see the sh2ac sorted out your latency problems , its just a shame and a total disappointment that the Hub 3.0 has done nothing at all for many people like yourself, other than cause them serious problems and undue stress.



Running ASUS RT-AC88U with Asuswrt-Merlin firmware

Thing is they said the expected fix is January, and it's still pretty clear from BQM that it hasn't been fixed. I will be sure to raise this with the complaints bod when he phones me next week, as I want to continue getting the additional monthly until it is resolved, as I am not getting the full 200Mb at peak times due to it.

If anything, it means I get a lower monthly bill at VM's loss, pressuring them into getting it resolved sooner... In an ideal world.