C7800 Dropping ISP connection

IThinkImMe · ‎2020-01-27

Been having a recurring issue with the connection to my ISP randomly dropping. Here are some of the facts:

ISP: Wave Broadband

Plan: 1GB/10mb

Router never loses power

Usually comes back within 60 seconds

In Cable Connections I randomly notice that only some of the downstream channels are active, sometimes 5-16 out of 32. And I never pick up a OFDMA upstream

Cable Information


Hardware Version	V1.07

Firmware Version	V3.01.36

Event Log

Time	Priority	Description
2020-01-27, 17:34:55.0	Critical (3)	Resetting the cable modem due to docsDevResetNow
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:52:23.0	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:53:09.0	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:53:09.0	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:53:13.0	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:53:19.0	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv4
Time Not Established	Warning (5)	DHCP WARNING - Non-critical field invalid in response ;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:58:21.0	Notice (6)	TLV-11 - unrecognized OID;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;

<tabindex=-1>Startup Procedure</tabindex=-1>

Procedure	Status	Comment
Acquire Downstream Channel	675000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	ENABLED	BPI+
IP Provisioning Mode	Honor MDD	IPv4 only

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	Uncorrectabables
1	Locked	QAM256	23	675000000 Hz	3.7 dBmV	38.1 dB	5	0
2	Locked	QAM256	1	543000000 Hz	6.4 dBmV	39.4 dB	5	0
3	Locked	QAM256	2	549000000 Hz	6.4 dBmV	39.4 dB	2	0
4	Locked	QAM256	3	555000000 Hz	6.4 dBmV	39.1 dB	6	0
5	Locked	QAM256	4	561000000 Hz	6.8 dBmV	39.4 dB	3	0
6	Locked	QAM256	5	567000000 Hz	6.6 dBmV	39.3 dB	7	0
7	Locked	QAM256	6	573000000 Hz	6.6 dBmV	39.4 dB	4	0
8	Locked	QAM256	7	579000000 Hz	6.9 dBmV	39.6 dB	2	0
9	Locked	QAM256	8	585000000 Hz	6.8 dBmV	39.3 dB	4	0
10	Locked	QAM256	9	591000000 Hz	6.8 dBmV	39.3 dB	5	0
11	Locked	QAM256	10	597000000 Hz	7.0 dBmV	39.7 dB	1	0
12	Locked	QAM256	11	603000000 Hz	7.1 dBmV	39.5 dB	1	0
13	Locked	QAM256	12	609000000 Hz	6.3 dBmV	39.4 dB	2	0
14	Locked	QAM256	13	615000000 Hz	4.8 dBmV	39.3 dB	4	0
15	Locked	QAM256	14	621000000 Hz	3.2 dBmV	38.8 dB	4	0
16	Locked	QAM256	15	627000000 Hz	4.6 dBmV	39.0 dB	4	0
17	Locked	QAM256	16	633000000 Hz	6.2 dBmV	39.2 dB	6	0
18	Locked	QAM256	17	639000000 Hz	6.5 dBmV	38.9 dB	4	0
19	Locked	QAM256	18	645000000 Hz	6.7 dBmV	38.6 dB	5	0
20	Locked	QAM256	19	651000000 Hz	6.7 dBmV	38.5 dB	10	0
21	Locked	QAM256	20	657000000 Hz	6.4 dBmV	38.8 dB	7	0
22	Locked	QAM256	21	663000000 Hz	6.2 dBmV	38.8 dB	8	0
23	Locked	QAM256	22	669000000 Hz	5.2 dBmV	38.6 dB	11	0
24	Locked	QAM256	24	681000000 Hz	3.0 dBmV	38.1 dB	8	0
25	Locked	QAM256	25	687000000 Hz	4.4 dBmV	38.5 dB	1	0
26	Locked	QAM256	26	693000000 Hz	5.7 dBmV	38.6 dB	6	0
27	Locked	QAM256	27	699000000 Hz	6.5 dBmV	38.6 dB	2	0
28	Locked	QAM256	28	705000000 Hz	7.1 dBmV	38.7 dB	4	0
29	Locked	QAM256	29	711000000 Hz	7.0 dBmV	38.3 dB	1	0
30	Locked	QAM256	30	717000000 Hz	7.2 dBmV	38.3 dB	2	0
31	Locked	QAM256	31	723000000 Hz	6.8 dBmV	37.9 dB	5	0
32	Locked	QAM256	32	729000000 Hz	7.0 dBmV	37.9 dB	1	0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	3	5120 Ksym/sec	22400000 Hz	42.5 dBmV
2	Locked	ATDMA	1	2560 Ksym/sec	17600000 Hz	41.0 dBmV
3	Locked	ATDMA	5	5120 Ksym/sec	28800000 Hz	43.8 dBmV
4	Locked	ATDMA	7	5120 Ksym/sec	35200000 Hz	43.8 dBmV
5	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0 dBmV
6	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0 dBmV
7	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0 dBmV
8	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>

Channel	Channel ID	Indicator	Subcarrier Zero Frequency	Active Subcarrier Number Range	Total Codewords	Uncorrectable Codewords
1	33	Backup Primary	347600000 Hz	1108 ~ 2987	19677886	0
2	0	Other	0 Hz	0 ~ 0	0	0

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>

Channel	UpstreamIsMuted	Ranging Status	Subcarrier Zero Frequency	Active Subcarrier Number Range	Symbols Per Frame	Tx Power
1		Other	0 Hz	0 ~ 0	0	0 dBmV
2		Other	0 Hz	0 ~ 0	0	0 dBmV

IThinkImMe · ‎2020-01-28

Wave has sent 3 techs on site and they all say the line is good. They're putting the fault on the router.

FURRYe38 · ‎2020-01-28

Try a different modem/router, or try a modem only and external router. See if problem clears or pertists. Possible faulty C7800 as well and just needs replacing.

IThinkImMe · ‎2020-01-28

Thanks for replying. I would like to state that I had another router previously that had the exact same symptoms as this one. Not sure of the exact model but it was an older Nighthawk. Support said I needed to update because it was DOCSIS 3.0 and my gig plan requires DOCSIS 3.1.

FURRYe38 · ‎2020-01-28

I would try another C7800 to see if this problem persists.

IF a different modem did, there could be problems from where you modem is up to the ISP service box. Though I kind of doubt this.

Trying of another C7800 should reveal something.

Jarudegirl1 · ‎2020-06-05

Hello,

My ISP is sayig the same thing about this router. When they put a Arris 3.1 on line, the SNR look fine. But with this NightHawk C7800. The tech from Atlantic Broadband said something about the SNR is registering 0 downstream on the 25 port downwards yet on the Arris modem he used not issue with the SNR.

My symptoms are peroidic connection drops.

Ex. Monday between 8am - 6pm, every 30 mins. Yet, the next day til today Friday functions fine.

So i really wonder if its the router or the ISP.

This issue have been happening every month at this time (4-10th day).

Right now, its working fine.

AM256	1	285000000 Hz	4.8 dBmV	38.8 dB	49	243
3	Locked	QAM256	2	291000000 Hz	4.8 dBmV	38.6 dB	62	235
4	Locked	QAM256	3	297000000 Hz	4.8 dBmV	38.5 dB	138	717
5	Locked	QAM256	4	303000000 Hz	4.8 dBmV	38.4 dB	56	231
6	Locked	QAM256	5	309000000 Hz	4.7 dBmV	38.4 dB	56	238
7	Locked	QAM256	6	315000000 Hz	4.6 dBmV	38.3 dB	42	250
8	Locked	QAM256	7	321000000 Hz	4.6 dBmV	38.4 dB	55	245
9	Locked	QAM256	8	327000000 Hz	4.8 dBmV	38.3 dB	62	239
10	Locked	QAM256	9	333000000 Hz	4.9 dBmV	38.4 dB	73	311
11	Locked	QAM256	11	345000000 Hz	5.4 dBmV	38.4 dB	78	366
12	Locked	QAM256	12	351000000 Hz	5.4 dBmV	38.4 dB	68	341
13	Locked	QAM256	13	357000000 Hz	5.3 dBmV	38.2 dB	78	355
14	Locked	QAM256	14	363000000 Hz	5.5 dBmV	38.1 dB	68	369
15	Locked	QAM256	15	369000000 Hz	5.5 dBmV	38.1 dB	82	368
16	Locked	QAM256	16	375000000 Hz	5.5 dBmV	38.0 dB	75	384
17	Locked	QAM256	17	381000000 Hz	5.5 dBmV	38.0 dB	74	396
18	Locked	QAM256	18	387000000 Hz	5.6 dBmV	37.9 dB	78	378
19	Locked	QAM256	19	393000000 Hz	5.5 dBmV	37.9 dB	83	365
20	Locked	QAM256	20	399000000 Hz	5.5 dBmV	37.9 dB	91	370
21	Locked	QAM256	21	405000000 Hz	5.5 dBmV	37.8 dB	81	363
22	Locked	QAM256	22	411000000 Hz	5.6 dBmV	37.8 dB	72	384
23	Locked	QAM256	23	417000000 Hz	5.6 dBmV	37.7 dB	68	372
24	Locked	QAM256	24	423000000 Hz	6.1 dBmV	38.0 dB	81	362
25	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0
26	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0
27	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0
28	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0
29	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0
30	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0
31	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	6	5120 Ksym/sec	32000000 Hz	46.5 dBmV
2	Locked	ATDMA	5	5120 Ksym/sec	38400000 Hz	47.0 dBmV
3	Locked	ATDMA	7	5120 Ksym/sec	25600000 Hz	46.5 dBmV
4	Locked	ATDMA	8	5120 Ksym/sec	19200000 Hz	46.5 dBmV
5	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0 dBmV
6	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0 dBmV
7	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0 dBmV
8	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>

Channel	Channel ID	Indicator	Subcarrier Zero Frequency	Active Subcarrier Number Range	Total Codewords	Uncorrectable Codewords
1	159	Non-Primary	419600000 Hz	296 ~ 7895	130412291	57091
2	0	Other	0 Hz	0 ~ 0	0	0

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>

Channel	UpstreamIsMuted	Ranging Status	Subcarrier Zero Frequency	Active Subcarrier Number Range	Symbols Per Frame	Tx Power
1		Other	0 Hz	0 ~ 0	0	0 dBmV
2		Other	0 Hz	0 ~ 0	0	0 dBmV

Current System Time: Fri, Jun 05, 2020 15:24:06

FURRYe38 · ‎2020-06-05

I would try another C7800 to see if this problem persists.

IF a different modem did, there could be problems from where you modem is up to the ISP service box. Though I kind of doubt this.

Trying of another C7800 should reveal something.

Make contact with NG support about an RMA if thats possible.

@vkdelta

@Blanca_O

@Jarudegirl1 wrote:
Hello,

My ISP is sayig the same thing about this router. When they put a Arris 3.1 on line, the SNR look fine. But with this NightHawk C7800. The tech from Atlantic Broadband said something about the SNR is registering 0 downstream on the 25 port downwards yet on the Arris modem he used not issue with the SNR.

My symptoms are peroidic connection drops.
Ex. Monday between 8am - 6pm, every 30 mins. Yet, the next day til today Friday functions fine.
So i really wonder if its the router or the ISP.
This issue have been happening every month at this time (4-10th day).

Right now, its working fine.

AM256 1 285000000 Hz 4.8 dBmV 38.8 dB 49 243
3 Locked QAM256 2 291000000 Hz 4.8 dBmV 38.6 dB 62 235
4 Locked QAM256 3 297000000 Hz 4.8 dBmV 38.5 dB 138 717
5 Locked QAM256 4 303000000 Hz 4.8 dBmV 38.4 dB 56 231
6 Locked QAM256 5 309000000 Hz 4.7 dBmV 38.4 dB 56 238
7 Locked QAM256 6 315000000 Hz 4.6 dBmV 38.3 dB 42 250
8 Locked QAM256 7 321000000 Hz 4.6 dBmV 38.4 dB 55 245
9 Locked QAM256 8 327000000 Hz 4.8 dBmV 38.3 dB 62 239
10 Locked QAM256 9 333000000 Hz 4.9 dBmV 38.4 dB 73 311
11 Locked QAM256 11 345000000 Hz 5.4 dBmV 38.4 dB 78 366
12 Locked QAM256 12 351000000 Hz 5.4 dBmV 38.4 dB 68 341
13 Locked QAM256 13 357000000 Hz 5.3 dBmV 38.2 dB 78 355
14 Locked QAM256 14 363000000 Hz 5.5 dBmV 38.1 dB 68 369
15 Locked QAM256 15 369000000 Hz 5.5 dBmV 38.1 dB 82 368
16 Locked QAM256 16 375000000 Hz 5.5 dBmV 38.0 dB 75 384
17 Locked QAM256 17 381000000 Hz 5.5 dBmV 38.0 dB 74 396
18 Locked QAM256 18 387000000 Hz 5.6 dBmV 37.9 dB 78 378
19 Locked QAM256 19 393000000 Hz 5.5 dBmV 37.9 dB 83 365
20 Locked QAM256 20 399000000 Hz 5.5 dBmV 37.9 dB 91 370
21 Locked QAM256 21 405000000 Hz 5.5 dBmV 37.8 dB 81 363
22 Locked QAM256 22 411000000 Hz 5.6 dBmV 37.8 dB 72 384
23 Locked QAM256 23 417000000 Hz 5.6 dBmV 37.7 dB 68 372
24 Locked QAM256 24 423000000 Hz 6.1 dBmV 38.0 dB 81 362
25 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
26 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
27 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
28 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
29 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
30 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
31 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 6 5120 Ksym/sec 32000000 Hz 46.5 dBmV
2 Locked ATDMA 5 5120 Ksym/sec 38400000 Hz 47.0 dBmV
3 Locked ATDMA 7 5120 Ksym/sec 25600000 Hz 46.5 dBmV
4 Locked ATDMA 8 5120 Ksym/sec 19200000 Hz 46.5 dBmV
5 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV
6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV
7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV
8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV
<tabindex=-1>Downstream OFDM Channels</tabindex=-1>
Channel Channel ID Indicator Subcarrier Zero Frequency Active Subcarrier Number Range Total Codewords Uncorrectable Codewords
1 159 Non-Primary 419600000 Hz 296 ~ 7895 130412291 57091
2 0 Other 0 Hz 0 ~ 0 0 0
<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>
Channel UpstreamIsMuted Ranging Status Subcarrier Zero Frequency Active Subcarrier Number Range Symbols Per Frame Tx Power
1 Other 0 Hz 0 ~ 0 0 0 dBmV
2 Other 0 Hz 0 ~ 0 0 0 dBmV
Current System Time: Fri, Jun 05, 2020 15:24:06

C7800 Dropping ISP connection

C7800 Dropping ISP connection

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