Constant low-level packet loss

[tievolu]

For the last month or so I've been getting constant low levels of packet loss (note the red signal at the top of the chart):

It doesn't seem to be affecting general day to day usage, but clearly something's not quite right. Rebooting the hub doesn't make any difference. The VM service page isn't working right now but last time I checked it indicated problems with TV in my area, but no issues with broadband.

Any ideas?

Downstream bonded channels

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

1	258750000	-3.5	37	256 qam	16
2	138750000	0.2	37	256 qam	1
3	146750000	0	37	256 qam	2
4	154750000	-0.7	37	256 qam	3
5	162750000	-1	37	256 qam	4
6	170750000	-1.5	37	256 qam	5
7	178750000	-1.9	37	256 qam	6
8	186750000	-2.2	37	256 qam	7
9	194750000	-2.7	37	256 qam	8
10	202750000	-3	37	256 qam	9
11	210750000	-3.5	37	256 qam	10
12	218750000	-3.9	37	256 qam	11
13	226750000	-4.5	37	256 qam	12
14	234750000	-4.7	37	256 qam	13
15	242750000	-4.7	37	256 qam	14
16	250750000	-4.2	37	256 qam	15
17	266750000	-3.9	37	256 qam	17
18	274750000	-3.7	37	256 qam	18
19	282750000	-3.5	37	256 qam	19
20	290750000	-4	37	256 qam	20
21	298750000	-3.7	37	256 qam	21
22	306750000	-3.7	37	256 qam	22
23	314750000	-4.2	37	256 qam	23
24	322750000	-4.2	37	256 qam	24

Downstream bonded channels

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

1	Locked	37.6	474	0
2	Locked	37.3	144	0
3	Locked	37.6	166	0
4	Locked	37.6	244	0
5	Locked	37.6	347	0
6	Locked	37.6	253	0
7	Locked	37.3	214	0
8	Locked	37.3	223	0
9	Locked	37.6	272	0
10	Locked	37.3	357	0
11	Locked	37.3	578	0
12	Locked	37.6	647	0
13	Locked	37.6	1001	0
14	Locked	37.3	1295	0
15	Locked	37.3	1128	0
16	Locked	37.6	735	0
17	Locked	37.6	756	0
18	Locked	37.6	586	0
19	Locked	37.3	645	0
20	Locked	37.6	875	0
21	Locked	37.3	681	0
22	Locked	37.6	766	0
23	Locked	37.6	1063	0
24	Locked	37.6	998	0

Upstream bonded channels

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

1	43100000	44.5	5120	64 qam	2
2	49599976	44.8	5120	64 qam	1
3	30100000	44.8	5120	64 qam	4
4	36600000	44	5120	64 qam	3
5	23600110	47.2	5120	16 qam	5

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	3	0
2	ATDMA	0	0	1	0
3	ATDMA	0	0	2	0
4	ATDMA	0	0	0	0
5	ATDMA	0	0	12	0

[jbrennand]

Firstly, can you also try the “free & automated” Service Status number - 0800 561 0061 - which usually gives the most up to date info. and tells you of more local issues down to street cab/ postcode level - than the area fault web site that covers 1000's of users

[tievolu]

No issues according to the automated service status phone line.

[Alex_RM]

Hi tievolu,

Thanks for posting, and sorry to hear you're having some issues with the Internet.

I've had a look at things from our side and can see the hubs downstream levels are not what they should be.

It's something I'll need to arrange a technician visit for, before I can do this I'll need a few details from you so I've popped you over a private message (purple envelope, top right hand corner)

Alex_Rm

[tievolu]

The technician came today and said the signal levels looked ok, although it wouldn't take much fluctuation to put them out of spec, so he went to the cabinet to bump the power level up a bit. However, he was unable locate the tone from the telco cable at the cabinet so he couldn't locate the coax cable, which means he was unable to do anything with the signal level.

He recommended a new pull of RG11 cable from the cabinet to my house due to the distance involved (he noted my neighbour's run is already RG11, whereas mine is RG6). Not sure quite how that will go because the ducting on the street isn't visible (presumably buried under the tarmac) and the cable on my property is buried under my drive. I suspect I'm going to end up with a cable in some big ugly ducting laying in my flower bed.

[tievolu]

The re-pull has actually been done very well. No visible cables on the street, an access point added in the pavement, and they buried the cable in some thin green ducting in the flower bed right up to the house.

Unfortunately they didn't have the right key for the cabinet so they couldn't actually connect the new cable. Hopefully that will be done soon and I should be able to tell pretty quickly if the issue is resolved.

[tievolu]

I've just been switched over to the new cable. Too early to tell whether it has resolved the packet loss, but here are the new signal levels:

Downstream bonded channels

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

1	258750000	10.5	38	256 qam	16
2	138750000	12.6	37	256 qam	1
3	146750000	12.5	37	256 qam	2
4	154750000	12	37	256 qam	3
5	162750000	11.8	37	256 qam	4
6	170750000	11.5	37	256 qam	5
7	178750000	11	37	256 qam	6
8	186750000	10.6	37	256 qam	7
9	194750000	10.4	37	256 qam	8
10	202750000	9.9	37	256 qam	9
11	210750000	9.6	37	256 qam	10
12	218750000	9.4	37	256 qam	11
13	226750000	9	37	256 qam	12
14	234750000	9	37	256 qam	13
15	242750000	9.1	37	256 qam	14
16	250750000	10	37	256 qam	15
17	266750000	10.5	38	256 qam	17
18	274750000	10.9	37	256 qam	18
19	282750000	10.9	37	256 qam	19
20	290750000	10.5	37	256 qam	20
21	298750000	11.3	37	256 qam	21
22	306750000	11	38	256 qam	22
23	314750000	11	38	256 qam	23
24	322750000	11	38	256 qam	24

Downstream bonded channels

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

1	Locked	38.9	4	0
2	Locked	37.6	0	0
3	Locked	37.6	16	0
4	Locked	37.6	0	0
5	Locked	37.6	6	0
6	Locked	37.6	0	0
7	Locked	37.6	0	0
8	Locked	37.3	5	0
9	Locked	37.6	5	0
10	Locked	37.6	11	0
11	Locked	37.6	4	0
12	Locked	37.3	6	0
13	Locked	37.6	5	0
14	Locked	37.6	0	0
15	Locked	37.6	0	0
16	Locked	37.6	7	0
17	Locked	38.6	0	0
18	Locked	37.6	6	0
19	Locked	37.6	5	0
20	Locked	37.6	4	0
21	Locked	37.6	5	0
22	Locked	38.6	6	0
23	Locked	38.6	5	0
24	Locked	38.6	4	0

Upstream bonded channels

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

1	43100000	33.3	5120	64 qam	2
2	49600000	33.3	5120	64 qam	1
3	36600000	33	5120	64 qam	3
4	23600166	36.8	5120	16 qam	5
5	30100000	34	5120	64 qam	4

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
5	ATDMA	0	0	0	0

[Matthew_ML]

Hey tievolu, thank you for reaching out and I am sorry to hear you are having some connection issues. 

I am going to send you a PM, please look out for the purple envelope. Thanks 

[tievolu]

Unfortunately the problem is not resolved. It's been mostly the same since the re-pull, but slightly worse today:

The large spikes of packet loss shown above are due to me trying various things like rebooting the hub, rebooting my router, switching out the coax cable from the wall for a different one etc., so those can be ignored. It's the constant background packet loss that's the problem. The level of packet loss is less than 1%, so it's not significant enough to cause major problems, but clearly something isn't right.

The signal levels all look ok (I think - see post above), and the hub status pages show zero post-RS errors. Given that I've tried switching my internal cabling, had an engineer visit (who said everything looked fine) and even had a complete re-pull from the cabinet, all to no avail, it seems that the problem is somewhere further upstream.

[tievolu]

I've also just noticed that my upload speed now maxes out at about 4-5Mbps instead of ~35Mbps. Something seems to have changed on Wednesday night or early Thursday morning. This seems to be when the packet loss got worse as well.