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]

[WildWayz]

WiFi results will always be worse than Ethernet.

Those are fine for WiFi but don't expect much more due to the nature of WiFi - doesn't matter if you are next to the router - there are so many  things which can interfere with the speeds... PLUS the speeds are theoretical and not actual. Same with Powerline Converters.

[theoven]

lel I get better speed with Vivid300
Max pick time hear.
http://prntscr.com/hdarsn

[ShadowOfDeth69]

Impressive. Wired or wireless?

[ShadowOfDeth69]

Yeah I'm well aware of the ins and outs of wifi Vs wired but I KNOW my phone is capable of much more. And honestly, there's nothing I can think of that would be causing such big variations in speeds. I really hope you're right, though.

[DarkBahamut]

Typically a realistic 'real world' expectation of peak WiFi speeds is to expect about half your current link speed in actual throughput. It can in some cases be a little higher, but 50% is a good figure to work with.

My phone (>3 years old) has a 2x2 ac chipset with a peak link speed of 866Mbps. Doing a cross network speedtest to a GbE host with the phone next to the router indicates a peak TCP throughput of 419Mbps. Pretty much bang on the 50% rule. A newer phone might squeeze a little more out of the link but 400-450Mbps is going to be about the top end possible.

[  7] local 192.168.1.75 port 5001 connected with 192.168.1.97 port 59893
[  5]  0.0-10.1 sec   126 MBytes   105 Mbits/sec
[  6]  0.0-10.1 sec   126 MBytes   104 Mbits/sec
[  7]  0.0-10.1 sec   126 MBytes   104 Mbits/sec
[  4]  0.0-10.1 sec   128 MBytes   106 Mbits/sec
[SUM]  0.0-10.1 sec   506 MBytes   419 Mbits/sec

Of course, this is only possible next to the router. Still, it is possible to max out a VIVID350 VM connection on WiFi on a phone if you keep the device close. If your struggling then you might have interference or aren't close enough to the router. make sure you're using a free 5Ghz channel.

[theoven]

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@ShadowOfDeth69 wrote:
Impressive. Wired or wireless?

---

wireless

[CraigC90]

My street has recently become cabled and I have placed an order for VIVID200, the top package offered in my postcode area. Installation is early next week.

As a gamer reading about the lag spikes caused by the Hub 3 is making me reconsider my order.

I mainly play Battlefield 1 on the PS4 Pro, are the lag spikes really that bad? Would putting the Hub 3 in modem mode and using my own router decrease the lag spikes?

This forum is full of examples which make me think that I should just stick with Sky Fibre until Virgin sort their kit out!

Surely they should let people use their own modems until they resolve or replace the Hub 3 with something more suitable!

There’s a lot of information on here but I was hoping somebody would take the time to give me a recap of where Virgin are at now with the issue? Have those testing new firmware actually had the issue fixed or is the Hub 3 unfixable? Cheers.

[WildWayz]

For some it is worse than others.

I have zero issues with lag spikes on the SH3.
Never have, unless playing against Aussies...

[boltedenergy]

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@CraigC90 wrote:
My street has recently become cabled and I have placed an order for VIVID200, the top package offered in my postcode area. Installation is early next week.

As a gamer reading about the lag spikes caused by the Hub 3 is making me reconsider my order.

I mainly play Battlefield 1 on the PS4 Pro, are the lag spikes really that bad? Would putting the Hub 3 in modem mode and using my own router decrease the lag spikes?

This forum is full of examples which make me think that I should just stick with Sky Fibre until Virgin sort their kit out!

Surely they should let people use their own modems until they resolve or replace the Hub 3 with something more suitable!

There’s a lot of information on here but I was hoping somebody would take the time to give me a recap of where Virgin are at now with the issue? Have those testing new firmware actually had the issue fixed or is the Hub 3 unfixable? Cheers.

---

Summary:

The latency issue is due to the actual hardware of the SH3, there is no alternative device to use with VM other than an old stock SH2/AC where existing customers have been extremely lucky or pushy to get it activated (difficult but not impossible)

There was a firmware fix promised by Intel. This fix, once applied (currently in very limited trials with some SH3 VM customers) is said to fix only ICMP and DNS lookups so its only a partial remedy. UDP and TCP could still be affected although we have a number of gamers in this thread who said its much better after fix applied.

[ShadowOfDeth69]

@CraigC90

I play Battlefield 1 on the Pro too and can honestly say I've never had any major problems at all. Maybe 1 or 2 missed shots but absolutely nothing game breaking whatsoever. No lag, rubber banding or anything. It plays for me just as smoothly as it did on my 80/20 Sky connection. I've seen the in-game network error indicators twice in the week I've been with VM and the Hub 3.

However, the other game I tried as a test was COD 4 Remastered and that played like **bleep** and was all over the place with lag.

Here's my BQM:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/4cdb4299421575a257c763a84f233480a5...

Nowhere near as bad as some I've seen in this particular thread. The red was me rebooting and the blue spikes are (I'm assuming) me downloading stuff and speed tests.

Virgin MUST know about the Hub 3 very obvious (in some cases) and well documented issues so I'd hope they'll be releasing new hardware like they did with the Superhub 2 and the 2ac.