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]

[purplemonkeyspa]

"I am keeping my fingers crossed here, but with downgrading my connection ready for it I assume I have spoken to the right guy!"

Bless your little cotton socks 🤣

I was spun that one too. The guy I spoke too seemed very sympathetic to the concerns I had at the time but said they had no SH2 stock and said if I could source my own then they'd happily activate it for me no problems.

Day of the installation the engineers turn up with (can you guess what?) yes, the SH3.

I was assured multiple times by the person it would not be a problem and not to worry. Take what they tell you over the phone with a pinch of salt. Lesson learned as a new customer on the first day. Don't get your hopes up.

[tommey]

---

@purplemonkeyspa wrote:




I can't do a BQM as I don't own a PC but I did one of these over wifi my first day connected:

---

Not sure why nobody mentioned this yet but (You do not need a PC to set up a BQM) pings are sent to your SH3 not PC so go set one up and we can all see what your connection really looks like.

https://www.thinkbroadband.com/broadband/monitoring/quality/create

[purplemonkeyspa]

What IP/Hostname should I use? I'm at work right now so not connected directly.

[theoven]

Hy, "This is the poor quality of my Superhub 3 connection" I don't think so its Superhub 3 problem.
I put the hub in modem mode and connect my brand new RT-AC5300 same ms spike lags in game, okay it's not so bad like sometimes get 31 ping but after 2 min u get 43 ping and get the little frez and again go back to 31 ping.... 12spike what game cache shows. I have the best internet in my village what I cant get VM300... 
#Live

https://www.thinkbroadband.com/broadband/monitoring/quality/share/5a6fbad1738d17df29036a10a272bdfa44a7181b

[tommey]

---

@purplemonkeyspa wrote:
What IP/Hostname should I use? I'm at work right now so not connected directly.

---

You will need to enter your external IP address, wait until you get home and go to http://whatsmyipaddress.org/

[purplemonkeyspa]

Right'o. Just so we're clear though, if the graph is **bleep** I make no apologies. I'm telling you, I have zero issues gaming.

[theoven]

I have made modem mode and I get the
Microsoft Windows [Version 10.0.16299.19]
(c) 2017 Microsoft Corporation. All rights reserved.

C:\Users\k****>ping -t 192.168.100.1

Pinging 192.168.100.1 with 32 bytes of data:
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=8ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=8ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=13ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=53ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=52ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=8ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=8ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=9ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=11ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=8ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=8ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=10ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=7ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=8ms TTL=63
Reply from 192.168.100.1: bytes=32 time=6ms TTL=63
Reply from 192.168.100.1: bytes=32 time=4ms TTL=63
Reply from 192.168.100.1: bytes=32 time=5ms TTL=63
Reply from 192.168.100.1: bytes=32 time=3ms TTL=63
Reply from 192.168.100.1: bytes=32 time=57ms TTL=63

[itinfocus]

I have also been upgraded to the new firmware.

Just a regular customer, but one who has complained both directly and on the forum in the past.

The new trial firmware does make the BQM graph look better. Not SH2 levels of better and nowhere near VDSL levels of consistency.

Web browsing performance is significantly improved for me. I no longer get random pages failing to load.

ICMP (ping) is now always routed via the hardware packet processor which is the reason that the obvious and easy test for the issues no longer exists.

As I don’t online game I can’t comment on the effects on this.

However there are still significant issues:

The ~2 second latency bug still effects my use or corporate VPN and VoIP services

To run a denial of service attack against the hub is still trivial. Anything over 1150 packets per second will totally disconnect ANY other service. Now considering that you can craft UDP packets as small as 28 bytes, this equates to approximately a 32KB/s stream.

The unreleased exploit code that forces the router to reboot is still effective against this firmware.

From testing done on Puma 7 devices (which the Hub 4 is expected to be) indicate that the performance is significantly improved but all of the security issues detailed above still exist.

[tommey]

Let's compare the SH3 with my BT Infinity Modem

First lets ping the Virgin Media SH3

Pinging SH3

Now lets do exactly the same test with my BT Modem

BT Infinity Modem

[deviousiphone]

well I can honestly say I can lay this issue to rest for the moment, it was a SH2AC I was sent, the guy even left notes on the system to make it smoother for me to activate. I am pretty impressed with this small part of a much larger crap storm, although I will continue to use my BT connection for gaming regardless, because it will still be better (if only marginally). I have run all the pingplotter tests over ICMP TCP & UDP, the issue is resolved for me on virgin now.