Inconsistent speeds

[s88urd]

Hi all,

Have had VM for around 2 weeks now and noticed that the speed im paying for (500) I never actually get. At first I thought this could be my AX router so i tested both cabled and wireless. I also negated the router and turned the VM hub back to router mode and tested with a cabled connection. 

Directly plugged into the VM hub (set in router mode) gives me around 300-350mbps.

An engineer came out last week to replace the onmibox outside and also put attenuators in place as my power levels were close to 15dBmV.

I find it a bit annoying that I could pay for the 350mbps service and actually get the speed i would be paying for, it seems silly for me paying the extra uplift from 350 and getting no benefit. Upload is always rock solid by the way.

Here is a extract of the stats from the router (straight after a reboot, so not sure if the Post RS errors are anything to worry about):

Downstream bonded channels

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

1	499000000	5.1	38	256 qam	12
2	411000000	4.5	38	256 qam	1
3	419000000	4.5	38	256 qam	2
4	427000000	4.6	38	256 qam	3
5	435000000	4.4	38	256 qam	4
6	443000000	4.5	38	256 qam	5
7	451000000	4.4	38	256 qam	6
8	459000000	4.3	38	256 qam	7
9	467000000	4.6	38	256 qam	8
10	475000000	4.6	38	256 qam	9
11	483000000	4.9	38	256 qam	10
12	491000000	5.1	38	256 qam	11
13	507000000	5.3	38	256 qam	13
14	515000000	4.8	38	256 qam	14
15	523000000	4.9	38	256 qam	15
16	531000000	5	38	256 qam	16
17	539000000	4.5	38	256 qam	17
18	547000000	5.1	38	256 qam	18
19	555000000	5.3	38	256 qam	19
20	563000000	5	38	256 qam	20
21	571000000	5.5	38	256 qam	21
22	579000000	5.3	38	256 qam	22
23	587000000	5.4	38	256 qam	23
24	595000000	5.1	38	256 qam	24

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	38.6	5	0
2	Locked	38.6	5	0
3	Locked	38.6	5	0
4	Locked	38.9	5	0
5	Locked	38.6	0	0
6	Locked	38.6	4	0
7	Locked	38.6	5	0
8	Locked	38.9	5	0
9	Locked	38.6	6	0
10	Locked	38.9	6	0
11	Locked	38.6	4	0
12	Locked	38.9	6	0
13	Locked	38.6	4	0
14	Locked	38.9	0	0
15	Locked	38.6	4	0
16	Locked	38.6	5	0
17	Locked	38.6	0	0
18	Locked	38.9	5	0
19	Locked	38.6	6	0
20	Locked	38.9	0	0
21	Locked	38.9	5	0
22	Locked	38.9	0	0
23	Locked	38.9	5	0
24	Locked	38.9	0	0

Is there anyone who can help at all?

[jbrennand]

can you test speeds in this way.....
_____________________________

As you expect >100Mbps then connect a 1GB enabled computer/laptop, with up to date drivers, via a NEW and working Cat5e/6a ethernet cable, directly to the Hub which you have put into “modem mode”....
(https://www.virginmedia.com/help/virgin-media-hub-modem-mode )
... This ensures that NO other devices are connected

Test speeds at https://speedtest.samknows.com/ - try on 2 different browsers.

If they are still low – boot your device into Windows safe+networking mode - to disable any potentially interfering software - and try again.

There are many posts on here (I have a list of ~30!) where QoS software, unknown/flaky software, old network card drivers, corrupted browsers, bad cables or other connected devices are limiting speeds on tests.

Report back what that gets.

[s88urd]

Hi John,

Have completed this using a CAT7 cable and still the same inconsistent results.

My wired in speed is awful, this has been tested on 2 different laptops with all power savings on the NIC disabled and safe mode with networking disabled.

The speed test test (although Wifi is never a good indication) is the same on mobile devices too. To achieve this i split the SSID's and bands and connected one wifi device to the 5ghz channel (while sitting around a meter unobstructed away), this was the only device configured with the new SSID and password.

When I test using my own router I have one single WiFi device connected (the laptop) which connects to the router at 2.4gbps (WiFi6) again I know WiFi is never really a good test. I can see the router is connected to the hub at 1000mbps and there is no QOS configured or enabled on the router.

It just doesnt seem to maintain a consistent speed, previously (at my old address) the speed would max out and pretty much stay there, in this case the speed fluctuates alot around 300-350mbps on the speed test and then gradually drops off even further.

Best regards

Sam

[jbrennand]

OK - for completeness can you post up the two tables of Upstream data and the Network logs.

Also have you set up a broadband quality monitor ? If not - do so.....

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

Also, do a quick check that all of your coax cable connections are in nice and "finger" tight - at the Hub and wall box and also at any connectors etc. Ensure there are no “unterminated cable loose ends. Check al ethernet connections are properly "seated".

Disconnect all the connections and reconnect to be sure. Also check that the internal wiring is ok with no kinking or chaffing, check that all looks good with the outside cabling and wall box (no “staples, etc.,) piercing the cables..

[s88urd]

Thanks John,

Have setup a broadband quality monitor so will give that a few days to gather data.

From the hub

Network Log:

Network Log

Time Priority Description

24/03/2022 06:59:6	Warning!	LAN login FAILED : Incorrect Username / Password / ConnectionType;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
23/03/2022 05:49:8	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/03/2022 21:10:23	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/03/2022 10:32:21	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/03/2022 10:32:14	Warning!	LAN login FAILED : Incorrect Username / Password / ConnectionType;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/03/2022 09:30:17	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/03/2022 03:18:37	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 19:02:44	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 19:02:37	Warning!	LAN login FAILED : Incorrect Username / Password / ConnectionType;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:55:47	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:35:58	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:35:54	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:35:36	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:35:36	Warning!	Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:35:31	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:32:41	critical	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:31:48	Warning!	Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:31:43	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:31:42	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/03/2022 09:31:42	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

Downstream info:

Refresh data

Downstream bonded channels

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

1	499000000	4.5	38	256 qam	12
2	411000000	3.9	38	256 qam	1
3	419000000	4	38	256 qam	2
4	427000000	4.1	38	256 qam	3
5	435000000	3.7	38	256 qam	4
6	443000000	3.9	38	256 qam	5
7	451000000	3.7	38	256 qam	6
8	459000000	3.7	38	256 qam	7
9	467000000	4	38	256 qam	8
10	475000000	4	38	256 qam	9
11	483000000	4	38	256 qam	10
12	491000000	4.5	38	256 qam	11
13	507000000	4.5	38	256 qam	13
14	515000000	4	38	256 qam	14
15	523000000	4.1	38	256 qam	15
16	531000000	4.1	38	256 qam	16
17	539000000	3.9	38	256 qam	17
18	547000000	4.4	38	256 qam	18
19	555000000	4.5	38	256 qam	19
20	563000000	4.3	38	256 qam	20
21	571000000	4.8	38	256 qam	21
22	579000000	4.5	38	256 qam	22
23	587000000	4.5	38	256 qam	23
24	595000000	4.3	38	256 qam	24

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	38.9	5	0
2	Locked	38.6	7	0
3	Locked	38.6	11	0
4	Locked	38.9	9	0
5	Locked	38.6	4	0
6	Locked	38.6	5	0
7	Locked	38.9	15	0
8	Locked	38.9	7	0
9	Locked	38.6	7	0
10	Locked	38.9	10	0
11	Locked	38.9	5	0
12	Locked	38.6	7	0
13	Locked	38.9	6	0
14	Locked	38.9	1	0
15	Locked	38.6	6	0
16	Locked	38.9	7	0
17	Locked	38.9	3	0
18	Locked	38.6	5	0
19	Locked	38.9	9	0
20	Locked	38.6	8	0
21	Locked	38.9	6	0
22	Locked	38.9	9	0
23	Locked	38.9	9	0
24	Locked	38.9	5	0

Upstream:

Refresh data

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

1	39399988	43.8	5120	64 qam	4
2	46200007	43.8	5120	64 qam	3
3	53700002	43.8	5120	64 qam	2
4	60300014	43.8	5120	64 qam	1

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	0	0
2	ATDMA	0	0	0	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0

All cables look good, the VM engineer made me a shorter cable due to the supplied cable being far to long for when my hub is from the wall socket. All coax connections are good and tight , the only 'kink' i guess you could say is one outside where the cable goes around brick work, and when it comes into the house and bends down into the white box on the inside of the house. Apart from this (and the cables looking old) it all looks good.

[jbrennand]

Nothing wrong with those stats all spot on. Lets see the BQM as soon as.

[Alex_RM]

Hi s88urd,

Thanks for posting and sorry to hear you've had some issues with your connection. 

Were you able to set up a BQM? 

If so can you please post the results?

I've had a look at things from our side and everything looks to be within the specifications we would expect.

Alex_Rm

[s88urd]

Hi Alex thanks for checking.

Things haven't been too bad recently. One really random thing I did notice is that if someone closes the door to the alleyway at the side of the house, I start to get post RS errors reporting on the hub. The cable from the ground goes around the outside of the house and down the alleyway and into the house that way.

[jbrennand]

Check the integrity of all of the cabling. If there is any damage to the sheathing with a nail in a clip piercing it of a sharp king with wiring exposed on the surface - they are likely sources of noise ingress

[s88urd]

There is a small bit of sheath missing from the cable external to the property running down the alleyway (i only noiced this by accident as I could see the white insulation showing through the rest of the black sheath), this comes directly from the virgin media 'brown box' at the front of the house. 

Is this something VM should replace? Its only a run of cable 5m long max. It also looks like the cable (where it goes around a corner of brick work) has rubbed against the brick work and may have become damaged too.

How do I go about arranging for this run of cable to be replaced please? 

I understand all cabling is virgin media's and so I dont want to replace it myself incase I cause problems.