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]

[audleyvm]

A tech website such as The Register might help get behind this, for someone who can compare latency across ISPs, provide a good explanation, would shame VM for not taking any action.

I mean comon.... they're still dishing out SH3 to new customers today who are going to experience this exact problem! Brushing this under the carpet like it's not a problem is just shameful and embarrassing. VM is supposed to be the leader of ISPs, they got the network right, the infrastructure, how could they fail at the very end... the end-user's router!

[audleyvm]

Oh wow, just found that The Register has been on this already:

https://www.theregister.co.uk/2016/12/03/intel_puma_chipset_firmware_fix/

https://www.theregister.co.uk/2017/07/21/virgin_media_puma_6_latency_issue_still_not_fixed_sixth_mon...

[WhyLieToUs]

The WiFi on ALL VM superhubs is total **bleep**e... 

[LdGallifryan]

ASUS GT-AC5300 & SUPERHUB 3.0 (In Modem Mode)

ASUS GT-AC5300 with Network Ping of 328ms!

[Andrew-G]

"Oh wow, just found that The Register has been on this already:"

Certainly has.  But Virginmedia still won't communicate with customers about the issue, still dish out the Hub 3, and still no official news regarding the sticking plaster firmware update, no news on any future Hub, no word on letting customers provide their own modem.

Virginmedia know full well there's a problem, but I daresay they've done a cost/benefit analysis, and concluded that doing nothing and ignoring the problem is the most profitable course of inaction.

[Luke_113]

I've just been on live chat with the Business 'support' team and the guy was actually useful, explained that there is an issue in my area (Reading) and gave me the master ticket reference, but low and behold nothing on Virgin's network status page, strange that! However in raising an issue about that I also asked about the Intel Puma 6 issue and if a fix is coming, and supposedly as we've all been told, its happening 'at the beginning of 2018' - I said I try and keep hope however have been told this for the last 8-9 months is the case, and he said he was sorry to hear that and had also been told that before but that they are actually pushing it out soon, I'd like to keep my fingers crossed but it still feels pie in the sky and also hard to believe anything that  Virgin say

[avro698]

Hey folks,

Haven't posted in this thread for a while, but have been reading almost daily, along with the thread going on over at dslreports.com

Anyhow, wow, I've had a Christmas present from VM - NOT !!!!

Just a small recap, I'm in area 25 and have been on 12 down / 2 up channels since Supercrud 3 was foisted upon me (was forced off a perfectly functioning SH1 on 152Mb service). Now on the vivid 200/12 service.

Back on Oct 17th I got the firmware update (9.1.116BA3), see below for transistion to new firmware.

Everything has continued much the same since then. The odd large download (4.3Gb) did take 40 minutes to download?? What the.....

Although web pages have been loading slightly quicker.

So I check again today, got the surprise of my life. Been switched to 24 down / 4 up and this is the result, you can just about see the point it was switched over.

Here's the downstream channels;

Channel Frequency(Hz) Power(dBmV)  SNR(dB)  Modulation  Channel ID

1       299000000       2.7         40        256 qam       21
2       323000000       2.7         40        256 qam       24
3       315000000       2.7         40        256 qam       23
4       307000000       2.5         40        256 qam       22
5       291000000       2.7         40        256 qam       20
6       283000000       3           40        256 qam       19
7       275000000       3           40        256 qam       18
8       267000000       3.2         40        256 qam       17
9       259000000       3.2         40        256 qam       16
10      251000000       3.4         38        256 qam       15
11      243000000       3.7         40        256 qam       14
12      235000000       3.9         40        256 qam       13
13      227000000       4           40        256 qam       12
14      219000000       4.4         40        256 qam       11
15      211000000       4.4         40        256 qam       10
16      203000000       4.5         40        256 qam       9
17      195000000       4.8         40        256 qam       8
18      187000000       5           40        256 qam       7
19      179000000       5           40        256 qam       6
20      171000000       5.4         40        256 qam       5
21      163000000       5.4         40        256 qam       4
22      155000000       5.5         40        256 qam       3
23      147000000       6           40        256 qam       2
24      139000000       6.4         40        256 qam       1

Here's the results of the speedtest, you'd think this would be shi** as well....

VM to VM:

VM to non-VM:

What do we make of this? Apart from a load of cr**.

Seriously VM, you need to start letting people who are willing to buy their own modem, to do so (I owned my own when contracted to Cabletel/NTL). If I spend a couple of hundred quid on a decent router, I'm more than prepared to do the same for a decent cable modem, Note - a modem, not a useless box of bits pretending to be something it isn't. Security on (Euro) Docsis 3.x modems (part of the standard) is much better than in the past so the chances of the VM network being hacked is negligible, so I don't see the problem here.

As many people have said on here, VM need to learn from this and learn quickly. Do not single source when you procure devices, as this type of mess can happen. It might keep your bean counters happy having negotiated a cheap box, but your customer base will suffer and is doing so.

I've been on cable since around 1998/99 and this is the worse I have ever seen it. I'm loathed to go over to BT but I may have to. I can't put up with this rubbish for much longer, especially at the price that it is.

A closing tip, for eveyone out there who hasn't done this yet, make sure you opt out of the VM WiFi hotspot (in your account area under My Profile, My Services), at least then you'll deprive VM of using your supercrud 3 and more importantly your electricity.

avro698

[nad223]

basically virgin bs media can do 1 i will be leaving in new year total worst customer service ever

[WildWayz]

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@avro698 wrote:

VM to VM:

VM to non-VM:

What do we make of this? Apart from a load of cr**.

---

Did your IP change?

[rio_w]

---

@avro698 wrote:

Hey folks,

Haven't posted in this thread for a while, but have been reading almost daily, along with the thread going on over at dslreports.com

Anyhow, wow, I've had a Christmas present from VM - NOT !!!!

Just a small recap, I'm in area 25 and have been on 12 down / 2 up channels since Supercrud 3 was foisted upon me (was forced off a perfectly functioning SH1 on 152Mb service). Now on the vivid 200/12 service.

Back on Oct 17th I got the firmware update (9.1.116BA3), see below for transistion to new firmware.

Everything has continued much 

So I check again today, got the surprise of my life. Been switched to 24 down / 4 up and this is the result, you can just about see the point it was switched over.

---

Has the option to allow ICMP packets through been changed?