Daily packet loss

[aefinity]

Hi all,

I'm having a problem with my M350 service where it has periods of packet loss during the day/night, causing problems with online video calls and buffering on streaming services.

I use the Hub in modem mode, plugged into the WAN port of a DrayTek router (with a failover VDSL OpenReach connection when VM is detected as down).

The drops can happen only once or twice a day or much more frequently, such as today:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/982243fe58f9c021ce7e65349467f9a2be7080c4-02-11-2021

 The live graph link:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/9f20f392c1a98c7837364977e6abfc6e8e99f6f7

The dropouts can be anywhere from 20 seconds to a few minutes, but in some cases have required the reboot of the router to return service.

I'll post my router stats in the next message - but any pointers or assistance on what might be causing these dropouts would be much appreciated!

Cheers.

[aefinity]

Cable Modem StatusItem Status Comments

Acquired Downstream Channel (Hz)	419000000	Locked
Ranged Upstream Channel (Hz)	46200000	Locked
Provisioning State	Online

Downstream bonded channels

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

1	419000000	-0.2	40	256 qam	36
2	235000000	3.9	40	256 qam	13
3	243000000	3.4	40	256 qam	14
4	251000000	2.7	40	256 qam	15
5	259000000	2.5	40	256 qam	16
6	267000000	2.7	40	256 qam	17
7	275000000	2.7	40	256 qam	18
8	283000000	2.5	40	256 qam	19
9	291000000	2.5	40	256 qam	20
10	299000000	2.5	40	256 qam	21
11	307000000	2.4	40	256 qam	22
12	315000000	2.5	40	256 qam	23
13	323000000	2.2	40	256 qam	24
14	331000000	2.2	40	256 qam	25
15	339000000	2.4	40	256 qam	26
16	347000000	2	40	256 qam	27
17	355000000	1.7	40	256 qam	28
18	363000000	1.5	40	256 qam	29
19	371000000	1.4	40	256 qam	30
20	379000000	1	40	256 qam	31
21	387000000	0.7	40	256 qam	32
22	395000000	0.7	40	256 qam	33
23	403000000	0.4	40	256 qam	34
24	411000000	0	40	256 qam	35

Downstream bonded channels

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

1	Locked	40.3	70799	159243
2	Locked	40.3	167686	444624
3	Locked	40.9	162547	423492
4	Locked	40.3	159207	420315
5	Locked	40.9	154045	391153
6	Locked	40.3	148745	373809
7	Locked	40.9	141802	365175
8	Locked	40.9	136961	355115
9	Locked	40.9	132291	339007
10	Locked	40.9	128249	312830
11	Locked	40.3	122824	300924
12	Locked	40.3	119646	287501
13	Locked	40.9	114033	280922
14	Locked	40.9	108806	271010
15	Locked	40.3	107506	244250
16	Locked	40.9	102636	243473
17	Locked	40.9	98206	232580
18	Locked	40.9	95097	221276
19	Locked	40.9	91807	209435
20	Locked	40.3	89432	193003
21	Locked	40.9	86602	194391
22	Locked	40.9	80834	193985
23	Locked	40.9	78093	176148
24	Locked	40.3	76841	166104

Upstream bonded channels

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

1	46200000	45.8	5120	64 qam	3
2	25800000	44	5120	64 qam	6
3	32600003	44	5120	64 qam	5
4	39400000	44	5120	64 qam	4

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	4	0
2	ATDMA	0	0	39	0
3	ATDMA	0	0	15	0
4	ATDMA	0	0	4	0

[aefinity]

Network Log

Time Priority Description

02/11/2021 12:18:41	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 11:01:57	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 10:59:37	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 10:58:43	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 09:12:34	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 08:38:6	notice	DHCP Renew - lease parameters tftp file-cmreg-vmdg505-bbt062-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 08:38:5	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 03:47:13	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 03:42:26	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 03:42:24	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 03:31:20	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/11/2021 03:30:43	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/11/2021 22:51:35	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/11/2021 22:50:50	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/11/2021 22:36:18	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/11/2021 22:36:10	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/11/2021 21:34:20	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/11/2021 21:34:2	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/11/2021 21:11:38	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/11/2021 21:11:24	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[jbrennand]

Dreadful BQM - poor Hub stats - need to start from a clean sheet - can you do this...
__________________________________________________________

Switch the Hub off and unplug it from the mains supply for five minutes. Whilst it's off, 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. 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.. Then switch the Hub back on and leave ~5 minutes

When all done, check back in the settings and ensure that the RS error counts and T3 errors have all reset to 0. Then check every hour or so to see if they start reappearing - they shouldn't. If they do (particularly the PostRS and T3 ones) you have a problem (noise) that only a Tech visit will sort.

[Tudor]

By the look of those figures I think you need a technician’s visit to rectify. Firstly though those figures are accumulative for the errors so some may be very old. Could you power cycle your hub and post a new set of figures after a few hours. Also try Calling Area faults on  0800 561 0061 or if you have a VM landline 150

If no faults found:

Call Customer Services on 0345 454 1111 or if you have a VM landline 150 or wait a day or two for a VM staff member to get to your post.

[aefinity]

Thanks both - I've powered down the router and checked the cables. It seems to be a little more stable today at least. Updated stats after nearly 4 hours:

Downstream bonded channels

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

1	Locked	38.9	44	24
2	Locked	40.9	96	58
3	Locked	40.3	109	55
4	Locked	40.9	93	49
5	Locked	40.3	86	67
6	Locked	40.3	101	40
7	Locked	40.3	76	53
8	Locked	40.3	72	49
9	Locked	40.3	85	40
10	Locked	40.3	83	29
11	Locked	40.3	74	25
12	Locked	40.3	66	25
13	Locked	40.3	70	28
14	Locked	40.3	79	17
15	Locked	38.9	61	26
16	Locked	40.3	78	18
17	Locked	40.3	70	13
18	Locked	40.3	68	22
19	Locked	40.3	66	13
20	Locked	38.9	69	15
21	Locked	40.3	50	22
22	Locked	40.3	56	15
23	Locked	40.3	44	15
24	Locked	38.9	57	12

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

[Tudor · Accepted solution]

Where some Pre RS errors are acceptable, Post ones are not.

Call Customer Services on 0345 454 1111 or if you have a VM landline 150 or wait a day or two for a VM staff member to get to your post.

[aefinity]

Thanks - I'll wait for someone to get in touch here, I find the phone service a little frustrating!

[aefinity]

Continues to get worse today:

Downstream bonded channels

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

1	Locked	38.9	369	1628
2	Locked	40.3	4934	1800
3	Locked	39.3	3406	1737
4	Locked	40.9	3328	1651
5	Locked	40.3	2993	1648
6	Locked	38.9	2696	1670
7	Locked	40.3	2789	1606
8	Locked	40.3	2052	1490
9	Locked	40.3	1539	1731
10	Locked	38.9	1475	1407
11	Locked	40.9	1285	1505
12	Locked	38.9	1255	1490
13	Locked	40.3	1232	1282
14	Locked	40.3	948	1516
15	Locked	38.9	853	1442
16	Locked	38.9	805	1492
17	Locked	40.3	787	1413
18	Locked	40.3	680	1669
19	Locked	40.3	610	1656
20	Locked	38.9	556	1319
21	Locked	38.9	571	1556
22	Locked	40.3	504	1546
23	Locked	40.3	383	1847
24	Locked	38.6	439	1480

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

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

https://www.thinkbroadband.com/broadband/monitoring/quality/share/477f7ffa57ed4900c4fb7b8df78e46e3c8a2c911-05-11-2021

 (ignoring the offline periods overnight, was changing some of the network setup)

[John_GS]

Hi @aefinity

Thanks for posting and apologies for the broadband issue.

This does indeed need a technician visit. 

I'll send you a PM now to assist further.