Intermittent slow speeds (~0.5Mbps) for 30s, Modem Mode, Normally 300Mbps+

[XDGFX]

Hi all,

I've seen similar posts to this one before, but they all either end without resolution, or after a VM member starts a private chat with the OP.

I get intermittent slow speeds on my VM 350 connection. Some days this will happen every 5-10 minutes, dropping the speed down to ~0.5Mbps, before returning back to ~full speed. Some days are without issue.

This happens on wired connections as well as WiFi.

I'm using Modem Mode, the router is an EdgeRouter X. Speedtests on the ER also show the same slowdown, so I'm fairly confident it's the VM hub.

As suggested in other threads I've set up a Broadband Quality Monitor here. So far it shows nothing too unexpected.

I have been getting critical errors in the VM hub network log (note MAC addresses have been redacted):

Time	Priority	Description
05/07/2021 16:58:16	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 16:46:17	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 10:49:29	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 08:32:43	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 08:23:39	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 08:04:22	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 08:04:14	Warning!	LAN login FAILED : Incorrect Username / Password / ConnectionType;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
04/07/2021 12:27:28	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
04/07/2021 10:46:6	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:51:40	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:37:55	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:37:31	critical	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:37:31	critical	Ranging Request Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:31:6	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:30:42	critical	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:30:42	critical	Ranging Request Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:24:18	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:23:54	critical	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:23:54	critical	Ranging Request Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2021 10:17:29	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

Most notably No Ranging Response received and SYNC Timing Synchronization failure

Upstream and downstream bonded channels are shown below, I'm not sure if these indicate an issue but each channel looks relatively consistent at least.

Downstream bonded channels
Channel	Frequency (Hz)	Power (dBmV)	SNR (dB)	Modulation	Channel ID
1	474250000	8	38	256 qam	9
2	410250000	9.6	38	256 qam	1
3	418250000	9.3	38	256 qam	2
4	426250000	8.9	40	256 qam	3
5	434250000	8.5	38	256 qam	4
6	442250000	8.3	40	256 qam	5
7	450250000	8	38	256 qam	6
8	458250000	7.9	38	256 qam	7
9	466250000	7.9	38	256 qam	8
10	482250000	8.1	38	256 qam	10
11	490250000	8	38	256 qam	11
12	498250000	7.8	38	256 qam	12
13	506250000	7.5	38	256 qam	13
14	514250000	7.5	38	256 qam	14
15	522250000	7.8	38	256 qam	15
16	530250000	7.5	38	256 qam	16
17	538250000	7	38	256 qam	17
18	546250000	6.6	38	256 qam	18
19	554250000	6.6	38	256 qam	19
20	562250000	6.8	38	256 qam	20
21	570250000	7	38	256 qam	21
22	578250000	6.6	38	256 qam	22
23	586250000	6.4	38	256 qam	23
24	594250000	6.5	38	256 qam	24


Downstream bonded channels
Channel	Locked Status	RxMER (dB)	Pre RS Errors	Post RS Errors
1	Locked	38.9	771	789
2	Locked	38.9	2346	452
3	Locked	39.3	2215	469
4	Locked	40.3	2000	522
5	Locked	38.9	2040	703
6	Locked	40.3	1805	712
7	Locked	38.9	1656	798
8	Locked	38.9	1338	875
9	Locked	38.9	991	1035
10	Locked	38.9	587	586
11	Locked	38.9	543	485
12	Locked	38.9	483	601
13	Locked	38.9	337	348
14	Locked	38.9	286	143
15	Locked	38.9	295	27
16	Locked	38.6	256	6
17	Locked	38.6	307	0
18	Locked	38.9	444	4
19	Locked	38.6	508	20
20	Locked	38.9	558	30
21	Locked	38.9	553	15
22	Locked	38.9	511	52
23	Locked	38.9	494	42
24	Locked	38.6	465	33


Upstream bonded channels
Channel	Frequency (Hz)	Power (dBmV)	Symbol Rate (ksps)	Modulation	Channel ID
1	39400000	39.2	5120	16 qam	2
2	25800024	32.5	5120	16 qam	4
3	32600380	33.2	5120	16 qam	3
4	46200000	35	5120	16 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	2	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0

Any suggestions on fixing this issue?

[jbrennand]

Thats one appalling BQM

Do you have other equipment (Switch/NAS/Powerlines/etc) connected to the Hub on ethernet cables? If so disconnect them all for an hour or two and see if the BQM "cleans up". 

As its been a few weeks....  - have you tried a pinhole reset of the Hub as per below (worth doing).

Finally post up all the Hub stats again
__________________________________

Note that a pinhole reset on a Hub3/4 can be a bit problematic - so do it (again) EXACTLY this way (not as the VM website says!).
Firstly, make sure the Hub's sticker/card with the two passwords on it is still there and legible or you will be stuffed ! If its not – DON’T DO IT !
With the Hub switched "on", disconnect any ethernet connections (leave the co-ax connected) and then push in the “reset pin” with the end of a paperclip/thin nail/SIM tray “tool” or similar (bigger items like ball point pen ends may not press it in far enough) until you feel it at the “stop point” and hold it there firmly for a "timed" minimum of 60 seconds do NOT manually restart the Hub at any time. Leave it 10' or so to stabilise and then your passwords/passphrase for both the Hub settings and the Wifi networks will revert to the two printed on the Hub sticker on its base/side/card. Make sure you use the wifi one for devices connecting to the wifi and the settings/admin one to access the Hub

See if that helps

[John_GS]

Hi XDGFX

Thanks for posting. I am sorry to hear of the broadband issues. 

There is an ongoing SNR (signal to noise ratio) issue in your area. F009274456 is the reference and the estimated fix date is the 21st September. 

Best,

[XDGFX]

Hi John(s)

> Do you have other equipment (Switch/NAS/Powerlines/etc) connected to the Hub on ethernet cables

I only have a single Ethernet cable going from the hub, through a Ubiquiti PoE injector, then into the EdgeRouter. Lots of stuff coming out of the ER.

I've replaced the PoE injector today to see if that helps things. I will try to unplug everything at some point but it might be a while before I can lose complete connection.

> As its been a few weeks....  - have you tried a pinhole reset of the Hub as per below (worth doing).

No... however I recently got an exciting email from VM saying Gig1 is now available in my area 😉 I've just installed the new Hub 4 today, that should rule out any issues I was having with the Hub 3.

> There is an ongoing SNR (signal to noise ratio) issue in your area. F009274456 is the reference and the estimated fix date is the 21st September.

I guess I'll test with the new equipment for the next few days/weeks and see if anything changes. I'm running out of network equipment to replace at this point - so hopefully I find the culprate soon!

[Paulina_Z]

Hi @XDGFX,

Thank you for coming back to us about this issue, I'm sorry to hear that you're still experiencing this issue.

Please monitor your connection and let us know how you're getting on after the estimates fix time for the SNR outage.

I have checked your account and the estimated fix time is still showing as 21/09/21 at 16:30.

Keep us updated and we'll be more than happy to help if this issue persists.

Thank you,

[XDGFX]

So far so good, though I still think it's too early to conclude a fix.

I'm being prompted to return the old VM router. If my issue is fixed the culprit was either the VM router or the PoE injector I replaced. Can my return be marked as potentially faulty to ensure it doesn't make it's way back with the working returns?

[Martin_N]

Thank you for keeping us posted on this. 

Has an agent advised that you return the router?

^Martin

[XDGFX]

Not an agent but when I upgraded to Gig1 it automatically requests a return, I had a reminder text and email a few days ago

[Zach_R]

Hi @XDGFX,

What model of router do you have that you're being asked to return?

Thanks,
 

[XDGFX]

VMDG505 / TG2492LG-VM

[Lee_R]

Hi @XDGFX thanks for coming back to us.

I'm assuming the faulty hub in question is a hub 3?

Regards

Lee_R