WiFi dropping in modem mode.

[Mtc10]

I recently switched to using my hub in modem mode with an external router, and have been experiencing constant drops in connection.

The network log shows a steady stream of errors each day. Today's is below...

21/09/2021 13:09:5	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:08:55	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:08:28	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:08:28	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:07:14	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:07:14	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:06:36	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:06:36	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:01:29	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:01:6	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 13:01:2	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 12:59:4	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 12:58:30	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 12:58:30	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 12:43:34	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 12:43:33	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 12:43:22	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 12:43:19	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 12:35:11	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/09/2021 12:34:58	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[lotharmat]

Post up the rest of the stats (Up and downstream - both tables)

Let's see if we can spot anything! Looking at the log, I'd be expecting a fair-few T3 timeouts and PostRS errors - possibly caused by an out of spec connection!

If not - VM would need to take a closer look!

[jbrennand]

What router make an model is it? If you take it out and put the Hub back to normal router mode - do the issues persist or go away?

[Mtc10]

Thanks for the reply, downstream and upstream are below...

Downstream bonded channels

Channel	Frequency (Hz)	Power (dBmV)	SNR (dB)	Modulation	Channel ID
1	299000000	12.4	38	256 qam	21
2	235000000	11.6	38	256 qam	13
3	243000000	11.5	38	256 qam	14
4	251000000	11.6	40	256 qam	15
5	259000000	11.9	40	256 qam	16
6	267000000	12.1	40	256 qam	17
7	275000000	12.5	40	256 qam	18
8	283000000	12.5	40	256 qam	19
9	291000000	12	38	256 qam	20
10	307000000	12.6	40	256 qam	22
11	315000000	12.5	38	256 qam	23
12	323000000	12	38	256 qam	24
13	331000000	12.1	38	256 qam	25
14	339000000	12.9	38	256 qam	26
15	347000000	12.6	40	256 qam	27
16	355000000	12.3	38	256 qam	28
17	363000000	12.5	38	256 qam	29
18	371000000	12.5	38	256 qam	30
19	379000000	12.3	38	256 qam	31
20	387000000	12.1	38	256 qam	32
21	395000000	12.8	38	256 qam	34
22	403000000	12.9	38	256 qam	35
23	411000000	12.4	38	256 qam	36
24	419000000	12.1	38	256 qam	37

Channel	Locked Status	RxMER (dB)	Pre RS Errors	Post RS Errors
1	Locked	38.9	437097	172605
2	Locked	38.9	1121588	295899
3	Locked	38.9	1008003	275058
4	Locked	40.3	899295	251279
5	Locked	40.3	753501	239727
6	Locked	40.3	624244	221870
7	Locked	40.3	529928	203887
8	Locked	40.3	485697	181190
9	Locked	38.6	459499	176235
10	Locked	40.3	390362	162569
11	Locked	38.9	363167	144284
12	Locked	38.9	334587	137435
13	Locked	38.9	299673	129407
14	Locked	38.9	269394	114154
15	Locked	40.3	240540	105429
16	Locked	38.9	226282	100892
17	Locked	38.9	214940	99661
18	Locked	38.9	197974	94083
19	Locked	38.9	184339	83161
20	Locked	38.9	171548	77727
21	Locked	38.9	157489	73413
22	Locked	38.9	149595	68780
23	Locked	38.9	145641	65894
24	Locked	38.9	134848	59986

Upstream bonded channels

Channel	Frequency (Hz)	Power (dBmV)	Symbol Rate (ksps)	Modulation	Channel ID
1	32600097	51	5120	64 qam	11
2	39400000	47.8	5120	64 qam	10
3	46199992	48	5120	64 qam	9
4	25800000	51	5120	64 qam	12

Channel	Channel Type	T1 Timeouts	T2 Timeouts	T3 Timeouts	T4 Timeouts
1	ATDMA	0	0	3	0
2	ATDMA	0	0	6	0
3	ATDMA	0	0	6	0
4	ATDMA	0	0	6	0

[lotharmat]

Thank you for this - Power is too high on downstream and some upstream channels!

You could call it in as a fault on 150
It'll ask you to reboot the hub (as you already have done - don't)
You will then be cut off
Wait a couple of minutes
Call 150 again - report a broadband fault - The system will recognise that you called before and transfer you to a person!

Or wait for VM staff to respond here (could take a day or so!)

[jbrennand]

Iotharmat is correct there - are issue on your down power levels. I will ask VM to come and comment - they will want you to put the Hub back into normal router mode - so you may as well do it and see if anything changes

[John_GS]

Hi @Mtc10

Thanks for posting and welcome to the community. 

You do indeed need a tech as all downstream are out of spec.

Will send you a PM now to assist 

Best,

[John_GS]

Hi Mtc10

Thanks for joining me on PM.

Just to confirm, the engineer visit was booked in. 

This can be tracked and/or altered in your online account

Let us know how the visit goes.

Best,