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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 tonycv51, it's in router mode.


@nickking wrote:

 

Hi tonycv51, it's in router mode.


Your graphs have some bad points both before and after and wondered if that was local (over)load on your hub, which could be a factor as in router mode, but more likely some local contention or other network issue in your area at peak times that would exist regardless of Puma 6 issues

My BQM (116V SH3 in modem mode) has lots of yellow but a steady blue regardless of peak times and activity, and no red (apart from very exceptional occasions)

 

Martin_D
Knows their stuff

The performance of my line has been good I have the hub in modem mode gaming is very good and our VoIP is also good

My set up: Hub 3 to the AC5300 I have asuswrt-Merlin firmware on my router plus some added extras - dnscrypt / AB-Solution / Skynet / pixelserv-tls

4119ce08e31bd9af86df1146f755c2395a79c090-18-04-2018.png



Welcome to the most friendliest community.

Have you got technical problem post it and we will help you fix it.


@Martin_D wrote:

The performance of my line has been good I have the hub in modem mode gaming is very good and our VoIP is also good

My set up: Hub 3 to the AC5300 I have asuswrt-Merlin firmware on my router plus some added extras - dnscrypt / AB-Solution / Skynet / pixelserv-tls

4119ce08e31bd9af86df1146f755c2395a79c090-18-04-2018.png


Martin,

To provide a holistic picture for everyone, can you confirm the following:

1.  Prior to .603, gaming was poor;

2.  Which games that were poor are now OK with .603.

Cheers

Seph - ( DEFROCKED - My advice is at your risk)

Prior to .603 I was on 9.1.116BA3 and so for me the last two update have been performing really well, But in terms of gaming I don't just put the improvement just on the firmware update. As we were suffering from overutilization and had other network side problems that have now been resolved

And just do remember we are in modem mode with our own router & a good QoS in place

The games that I have seen a improvement are battlefield 1, Grand Theft Auto and some times destiny 2

So to end the latest update .603 has helped but its not going to solve all your problems a good router will help a lot and so will QoS if it is configured correctly for your needs.

If you know a little more about networking have a look at stuff like fq_codel and dnscrypt has some nice config options like - https://github.com/jedisct1/dnscrypt-proxy/wiki/Caching



Welcome to the most friendliest community.

Have you got technical problem post it and we will help you fix it.

What you've said, Martin, is very important. Maybe I haven't looked hard enough within this thread, but there is little reported for gaming as direct comparison between 9.1.116V and .603.

Seph - ( DEFROCKED - My advice is at your risk)


@Sephiroth wrote:
What you've said, Martin, is very important. Maybe I haven't looked hard enough within this thread, but there is little reported for gaming as direct comparison between 9.1.116V and .603.


I use hub 3 in modem mode with Asus router like the above poster on latest .603, played a lot of BF1 the last week or so and have had no lag or any issues in this game what so ever.

Unfortunately I cant comment on how it was prior as I only got my hub 3 5 weeks ago and was immediately updated to .603 and prior to that I had a hub 1.

 

And I agree with you that not enough is reported on .603 gaming, most who post are still on 116 it seems?

 

Adduxi
Very Insightful Person
Very Insightful Person

@Sephiroth wrote:
What you've said, Martin, is very important. Maybe I haven't looked hard enough within this thread, but there is little reported for gaming as direct comparison between 9.1.116V and .603.


Seph, for the gaming that I do, mostly Destiny 2, I can't honestly tell any difference between the firmware releases. 

Perhaps I'm too long in the tooth to be a great shot  🙂

However, I still would be of the opinion the Puma chipset is flawed, especially when reading the low level discussions elsewhere.

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


@Adduxi wrote:

@Sephiroth wrote:
What you've said, Martin, is very important. Maybe I haven't looked hard enough within this thread, but there is little reported for gaming as direct comparison between 9.1.116V and .603.


Seph, for the gaming that I do, mostly Destiny 2, I can't honestly tell any difference between the firmware releases. 

Perhaps I'm too long in the tooth to be a great shot  🙂

However, I still would be of the opinion the Puma chipset is flawed, especially when reading the low level discussions elsewhere.


I play Destiny 2 and I simply find it unplayable of my Vivid 200 Gamer with the HUB3 in modem mode, so much so I had BT Fibre installed now I have no issues.

However I am still stuck with firmware version 9.1.116V, not that a new firmware will fix my connection issues, and I think Virgin themselves have given up on my CMTS anyway.


@Martin_D wrote:

Prior to .603 I was on 9.1.116BA3 and so for me the last two update have been performing really well, But in terms of gaming I don't just put the improvement just on the firmware update. As we were suffering from overutilization and had other network side problems that have now been resolved

And just do remember we are in modem mode with our own router & a good QoS in place

The games that I have seen a improvement are battlefield 1, Grand Theft Auto and some times destiny 2

So to end the latest update .603 has helped but its not going to solve all your problems a good router will help a lot and so will QoS if it is configured correctly for your needs.

If you know a little more about networking have a look at stuff like fq_codel and dnscrypt has some nice config options like - https://github.com/jedisct1/dnscrypt-proxy/wiki/Caching


This might be slightly off topic but....

I have adaptive gaming QoS on my Asus AC68U, stock firmware with SH3 in modem mode (have never felt the need to go merlin, and was thinking of upgrading to AC86U and don’t think Merlin is available yet). I don’t have any devices prioritised. My question is that there are 2 PS4s in the house used for both gaming and streaming. They are the only devices used for gaming. One PS4 one of my kids sometimes watches YouTube within the PS4 browser so that he can still see notifications etc. The other PS4 is sometimes used for Now TV in that location. Is it worth removing non gaming activity from the PS4s if possible and prioritising those devices, or just rely on standard adaptive gaming QoS via traffic type ?  If I prioritise them and they’re still used for streaming then will that adversely impact other users eg watching Netflix 4K in the main TV room ?