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4 Messages

Friday, June 12th, 2015 12:00 PM

Ongoing issue with large packet delays and loss

I have been seeing a persistent issue with large packet delays (8000ms+) and loss for almost two weeks.

 

All of my observations are based on pinging my modem's immediate gateway (first hop away).  I use a dd-wrt NAT/router most of the time and run pings from a windows PC connected to via ethernet.  I have ruled out issues with my hardware by connecting a lapop directly to the modem to confirm the same behavior, having the national comcast support confirm pinging the modem from their side, and by running pings on the dd-wrt modem itself simultaneously.

 

When I talk about loss it is pings that are truly lost or those delayed more than 2000ms.

 

The behavior I see is intermittent in severity.  It has varied from 0.5% loss to 10% loss, with 1000ms+ delays occurring a similar rates during those times.  Periods of severity last for many hours at a time.  For example, yesterday I observe low severity loss occurring from ??am to ~12pm.  Then the issue was completely absent ~12pm to ~4pm.  Then the issue returned to low severity 4pm to ~7pm.  At 7pm it increased to extreme severity (unusable) and this persisted for hours.

 

A nearly identical issue was occurring and resolved about 2 months ago.  At that time, I was informed that an address on a nearby street was identified as a source of noise and a trap put on it.  This completely corrected the issue.

 

On the morning of 6/2, I observed Comcast technicians working at the junction box my cable is run from.  They explained that an adjacent address's cable had been cut by landscapers and they were repairing it.  They asked if our service was ok, and we had no complaints.  10pm that night is when I first began observing the new delay/loss problem.

 

Since then, Comcast technicians have been out to check my the hardware at my property and the junction box multiple times.  They have used their TDR tester on my line from the box multiple times.  They have chased noisy houses in the area and put traps on them.  But these technicians tends to arrive during low or no severity periods, and the problem remains.

 

I have been in contact with somebody described as the area supervisor and he has indicated that they want to help and been tolerant of my frequent communication on this issue (thank you!).  But I am getting concerned that they are out of ideas.

 

Any suggestions on what I can do to help them help me resolve this completely?

 

I have done some tests, like running pings from a customer 5 addresses away and on a different junction box -- this showed absolutely no issue while my address was seeing high severity loss/delays.  But my ability to pester other customers to let me run tests is very limited.

 

Yesterday I adjusted my monitoring to run hrPing with timestamp logging continually so that I have a more objective history to point at.  But when high severity periods often occurr after hours I can't get technicians to come investigate...

 

An example of my monitoring is in the spoiler tag below, showing the issue at low severity and then suddenly disappearing almost completely at 10:49am.  Based on prior experience I am expecting the issue to return at low severity around 4pm today (and steadily get worse).  The ... is where I elided hours of the same behavior.  I noted near the end where I have seen almost no issue for hours.

 

Spoiler
2015-06-11 22:51:55.476: -F pingtest.txt -qr 50 -t -T -s 500 x.x.x.x
Source address is 192.168.1.65; using ICMP echo-request, ID=bc11
Pinging x.x.x.x [x.x.x.x]
with 32 bytes data (60 bytes IP):

...
2015-06-11 23:42:33.534: Timeout waiting for seq=17b9
2015-06-11 23:43:09.035: Timeout waiting for seq=17ff
2015-06-11 23:43:26.050: From x.x.x.x: bytes=60 seq=1824 TTL=254 ID=5a1e time=1015.087ms
2015-06-11 23:43:26.051: From x.x.x.x: bytes=60 seq=1825 TTL=254 ID=5a45 time=516.007ms
2015-06-11 23:43:28.536: Timeout waiting for seq=1826
2015-06-11 23:43:50.036: Timeout waiting for seq=1852
2015-06-11 23:43:51.036: Timeout waiting for seq=1853
2015-06-11 23:43:51.036: Timeout waiting for seq=1854
2015-06-11 23:43:52.036: Timeout waiting for seq=1855
2015-06-11 23:43:52.036: Timeout waiting for seq=1856
2015-06-11 23:43:52.050: From x.x.x.x: bytes=60 SEQ=1859 TTL=254 ID=5fe8 time=514.929ms
2015-06-11 23:43:53.036: Timeout waiting for seq=1857
...
2015-06-12 01:47:09.667: Timeout waiting for seq=5220
2015-06-12 01:47:21.167: Timeout waiting for seq=5238
2015-06-12 01:47:48.667: Timeout waiting for seq=526e
2015-06-12 01:48:15.168: Timeout waiting for seq=52a4
2015-06-12 01:48:20.168: Timeout waiting for seq=52ae
2015-06-12 01:48:51.669: Timeout waiting for seq=52ec
2015-06-12 01:50:03.170: Timeout waiting for seq=537c
2015-06-12 01:50:09.170: Timeout waiting for seq=5388
2015-06-12 01:50:38.671: Timeout waiting for seq=53c3
2015-06-12 01:51:06.671: Timeout waiting for seq=53fb
2015-06-12 01:51:23.672: Timeout waiting for seq=541d
2015-06-12 01:51:40.185: From x.x.x.x: bytes=60 SEQ=5441 TTL=254 ID=2ced time=514.271ms
2015-06-12 01:51:41.172: Timeout waiting for seq=5440
2015-06-12 01:51:44.687: From x.x.x.x: bytes=60 SEQ=544a TTL=254 ID=2e91 time=515.933ms
2015-06-12 01:51:46.172: Timeout waiting for seq=5449
2015-06-12 01:52:49.183: Timeout waiting for seq=54c8
...
2015-06-12 03:40:22.287: Timeout waiting for seq=8732
2015-06-12 03:40:53.787: Timeout waiting for seq=8770
2015-06-12 03:40:56.788: Timeout waiting for seq=8776
2015-06-12 03:41:09.788: Timeout waiting for seq=8790
2015-06-12 03:41:09.788: Timeout waiting for seq=8791
2015-06-12 03:41:11.287: Timeout waiting for seq=8792
2015-06-12 03:41:11.287: Timeout waiting for seq=8793
2015-06-12 03:41:13.287: Timeout waiting for seq=8796
2015-06-12 03:41:13.287: Timeout waiting for seq=8797
2015-06-12 03:41:13.287: Timeout waiting for seq=8798
2015-06-12 03:41:14.288: Timeout waiting for seq=8799
2015-06-12 03:41:14.288: Timeout waiting for seq=879a
2015-06-12 03:41:14.303: From x.x.x.x: bytes=60 SEQ=879d TTL=254 ID=0f7a time=515.466ms
2015-06-12 03:41:15.288: Timeout waiting for seq=879b
2015-06-12 03:41:15.288: Timeout waiting for seq=879c
2015-06-12 03:41:24.288: Timeout waiting for seq=87ad
2015-06-12 03:42:22.289: Timeout waiting for seq=8821
2015-06-12 03:42:43.790: Timeout waiting for seq=884d
2015-06-12 03:45:16.792: Timeout waiting for seq=897e
2015-06-12 03:46:17.293: Timeout waiting for seq=89f6
2015-06-12 03:46:55.430: From x.x.x.x: bytes=60 SEQ=8a47 TTL=254 ID=7898 time=636.859ms
2015-06-12 03:46:59.794: Timeout waiting for seq=8a4c
2015-06-12 03:47:08.294: Timeout waiting for seq=8a5e
2015-06-12 03:47:57.295: Timeout waiting for seq=8abe
2015-06-12 03:48:37.796: Timeout waiting for seq=8b10
2015-06-12 03:49:09.297: Timeout waiting for seq=8b4f
2015-06-12 03:50:29.297: Timeout waiting for seq=8bee
...
2015-06-12 06:33:12.471: Timeout waiting for seq=d835
2015-06-12 06:33:59.471: Timeout waiting for seq=d893
2015-06-12 06:38:36.976: Timeout waiting for seq=dabf
2015-06-12 06:38:43.977: Timeout waiting for seq=dacc
2015-06-12 06:41:48.979: Timeout waiting for seq=dc3e
2015-06-12 06:42:55.981: Timeout waiting for seq=dcc4
2015-06-12 06:43:02.480: Timeout waiting for seq=dcd2
2015-06-12 06:43:36.981: Timeout waiting for seq=dd17
2015-06-12 06:44:16.982: Timeout waiting for seq=dd66
2015-06-12 06:44:47.482: Timeout waiting for seq=dda3
2015-06-12 06:44:52.001: From x.x.x.x: bytes=60 SEQ=ddb0 TTL=254 ID=6b64 time=518.047ms
2015-06-12 06:44:53.483: Timeout waiting for seq=ddaf
2015-06-12 06:45:30.984: Timeout waiting for seq=ddfb
2015-06-12 06:46:08.984: Timeout waiting for seq=de46
2015-06-12 06:46:42.485: Timeout waiting for seq=de89
...
*** Issue continues for hours ***
2015-06-12 08:52:05.617: Timeout waiting for seq=194f
2015-06-12 08:52:08.617: Timeout waiting for seq=1956
2015-06-12 08:53:04.214: From x.x.x.x: bytes=60 seq=19ca TTL=254 ID=bdd6 time=95.697ms
2015-06-12 08:53:57.620: Timeout waiting for seq=1a30
2015-06-12 08:54:18.120: Timeout waiting for seq=1a59
...
2015-06-12 09:01:37.628: Timeout waiting for seq=1dc8
2015-06-12 09:01:40.628: Timeout waiting for seq=1dce
2015-06-12 09:02:12.684: From x.x.x.x: bytes=60 seq=1e13 TTL=254 ID=962f time=56.450ms
2015-06-12 09:03:16.630: Timeout waiting for seq=1e8e
2015-06-12 09:03:43.130: Timeout waiting for seq=1ec3
2015-06-12 09:04:09.631: Timeout waiting for seq=1ef9
2015-06-12 09:05:55.633: Timeout waiting for seq=1fcd
2015-06-12 09:06:53.133: Timeout waiting for seq=2040
2015-06-12 09:08:01.135: Timeout waiting for seq=20c7
2015-06-12 09:09:08.636: Timeout waiting for seq=214e
2015-06-12 09:09:08.636: Timeout waiting for seq=214f
2015-06-12 09:09:09.636: Timeout waiting for seq=2150
2015-06-12 09:09:09.636: Timeout waiting for seq=2151
2015-06-12 09:09:10.636: Timeout waiting for seq=2152
2015-06-12 09:09:10.636: Timeout waiting for seq=2153
2015-06-12 09:09:10.658: From x.x.x.x: bytes=60 SEQ=2156 TTL=254 ID=1ed4 time=522.790ms
2015-06-12 09:09:11.636: Timeout waiting for seq=2154
2015-06-12 09:09:11.636: Timeout waiting for seq=2155
2015-06-12 09:12:37.640: Timeout waiting for seq=22f0
2015-06-12 09:12:38.640: Timeout waiting for seq=22f2
2015-06-12 09:13:54.141: Timeout waiting for seq=2389
2015-06-12 09:21:28.149: Timeout waiting for seq=2715
2015-06-12 09:21:29.149: Timeout waiting for seq=2717
2015-06-12 09:22:18.150: Timeout waiting for seq=277a
2015-06-12 09:24:26.652: Timeout waiting for seq=287a
2015-06-12 09:27:00.655: Timeout waiting for seq=29ae
2015-06-12 09:30:52.159: Timeout waiting for seq=2b7e
2015-06-12 09:35:48.164: Timeout waiting for seq=2dce
2015-06-12 09:35:49.164: Timeout waiting for seq=2dcf
2015-06-12 09:38:42.667: Timeout waiting for seq=2f2b
2015-06-12 09:39:23.668: Timeout waiting for seq=2f7c
2015-06-12 09:42:29.691: From x.x.x.x: bytes=60 SEQ=30f4 TTL=254 ID=30ff time=520.188ms
2015-06-12 09:42:30.171: Timeout waiting for seq=30f1
2015-06-12 09:42:30.171: Timeout waiting for seq=30f2
2015-06-12 09:42:31.171: Timeout waiting for seq=30f3
2015-06-12 09:42:47.671: Timeout waiting for seq=3114
2015-06-12 09:44:09.173: Timeout waiting for seq=31b7
2015-06-12 09:49:47.679: Timeout waiting for seq=345d
2015-06-12 10:07:50.198: Timeout waiting for seq=3cd2
2015-06-12 10:49:14.242: Timeout waiting for seq=503a
2015-06-12 10:49:15.242: Timeout waiting for seq=503b
2015-06-12 10:49:15.242: Timeout waiting for seq=503c
2015-06-12 10:49:16.242: Timeout waiting for seq=503d
2015-06-12 10:49:16.242: Timeout waiting for seq=503e
2015-06-12 10:49:17.242: Timeout waiting for seq=503f
*** Nothing lost for 2 hours ***
2015-06-12 12:33:11.015: Timeout waiting for seq=2d8e
2015-06-12 12:33:11.015: Timeout waiting for seq=2d8f
2015-06-12 12:33:12.015: Timeout waiting for seq=2d90
2015-06-12 12:33:13.015: Timeout waiting for seq=2d93
2015-06-12 12:33:14.015: Timeout waiting for seq=2d94
2015-06-12 12:33:14.015: Timeout waiting for seq=2d95
2015-06-12 12:33:15.015: Timeout waiting for seq=2d96
2015-06-12 12:33:15.015: Timeout waiting for seq=2d97
2015-06-12 12:33:15.813: From x.x.x.x: bytes=60 SEQ=2d9b TTL=254 ID=832c time=798.517ms
2015-06-12 12:33:15.813: From x.x.x.x: bytes=60 seq=2d9c TTL=254 ID=8361 time=298.762ms
2015-06-12 12:33:16.015: Timeout waiting for seq=2d98
2015-06-12 12:33:16.015: Timeout waiting for seq=2d99
2015-06-12 12:33:17.015: Timeout waiting for seq=2d9a
2015-06-12 12:53:04.193: From x.x.x.x: bytes=60 seq=36e5 TTL=254 ID=bbd4 time=157.226ms
2015-06-12 13:39:18.585: Timeout waiting for seq=4c8d
2015-06-12 13:39:19.585: Timeout waiting for seq=4c8f
2015-06-12 13:39:19.585: Timeout waiting for seq=4c90
2015-06-12 13:39:20.585: Timeout waiting for seq=4c91
2015-06-12 13:39:20.585: Timeout waiting for seq=4c92
2015-06-12 13:39:21.585: Timeout waiting for seq=4c93
2015-06-12 13:39:21.585: Timeout waiting for seq=4c94
2015-06-12 13:39:22.018: From x.x.x.x: bytes=60 SEQ=4c97 TTL=254 ID=fa1a time=933.352ms
2015-06-12 13:39:22.018: From x.x.x.x: bytes=60 seq=4c98 TTL=254 ID=fa2f time=433.507ms
2015-06-12 13:39:22.585: Timeout waiting for seq=4c95
2015-06-12 13:39:22.585: Timeout waiting for seq=4c96
*** no other drops/delays as of 2:46 PM 6/12/2015

 I understand the concept of noise ingress and that another customer could be impacting me, but it strains belief that this problem started on the same day there was a major disturbance at my junction box and is not related.  Even though the TDR test says my cable is fine, I have been asking them to run a very long temporary cable to be completely sure...

 

One final note, the adjacent property owner informed me that this junction box was left open exposed to the element for some numbers of weeks.  She had been calling comcast repeatedly until they finally addressed it.  I don't know if these things are really supposed to protect their contents from the elements though.

New Member

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4 Messages

9 years ago

Seconds after 4pm, a burst of delays and loss.  I saw this in my hrPing results and the ping running on the router.

 

What could possibly be causing interference at such a precise time??

 

 

Spoiler
2015-06-12 13:39:22.585: Timeout waiting for seq=4c96
*** Hours of no problem***
2015-06-12 16:00:10.249: From x.x.x.x: bytes=60 SEQ=8e98 TTL=254 ID=8b8c time=515.022ms
2015-06-12 16:00:11.734: Timeout waiting for seq=8e97
2015-06-12 16:00:12.735: Timeout waiting for seq=8e9a
2015-06-12 16:00:13.735: Timeout waiting for seq=8e9b
2015-06-12 16:00:13.735: Timeout waiting for seq=8e9c
2015-06-12 16:00:14.735: Timeout waiting for seq=8e9d
2015-06-12 16:00:14.735: Timeout waiting for seq=8e9e
2015-06-12 16:00:15.735: Timeout waiting for seq=8e9f
2015-06-12 16:00:15.735: Timeout waiting for seq=8ea0
2015-06-12 16:00:15.781: From x.x.x.x: bytes=60 SEQ=8ea3 TTL=254 ID=8cb3 time=546.198ms
2015-06-12 16:00:16.735: Timeout waiting for seq=8ea1
2015-06-12 16:00:16.735: Timeout waiting for seq=8ea2
2015-06-12 16:00:18.735: Timeout waiting for seq=8ea5
2015-06-12 16:00:18.735: Timeout waiting for seq=8ea6
2015-06-12 16:00:19.735: Timeout waiting for seq=8ea7
2015-06-12 16:00:19.735: Timeout waiting for seq=8ea8
2015-06-12 16:00:20.735: Timeout waiting for seq=8ea9
2015-06-12 16:00:20.735: Timeout waiting for seq=8eaa
2015-06-12 16:00:20.750: From x.x.x.x: bytes=60 SEQ=8ead TTL=254 ID=8e67 time=515.514ms
2015-06-12 16:00:21.735: Timeout waiting for seq=8eab
2015-06-12 16:00:21.735: Timeout waiting for seq=8eac
2015-06-12 16:00:24.735: Timeout waiting for seq=8eb0
2015-06-12 16:00:24.735: Timeout waiting for seq=8eb1
2015-06-12 16:00:24.735: Timeout waiting for seq=8eb2
2015-06-12 16:00:25.735: Timeout waiting for seq=8eb3
2015-06-12 16:00:25.735: Timeout waiting for seq=8eb4
2015-06-12 16:00:25.767: From x.x.x.x: bytes=60 SEQ=8eb7 TTL=254 ID=8f7e time=532.055ms
2015-06-12 16:00:26.735: Timeout waiting for seq=8eb5
2015-06-12 16:00:26.735: Timeout waiting for seq=8eb6
2015-06-12 16:00:28.735: Timeout waiting for seq=8eba
2015-06-12 16:00:29.735: Timeout waiting for seq=8ebb
2015-06-12 16:00:29.735: Timeout waiting for seq=8ebc
2015-06-12 16:00:30.736: Timeout waiting for seq=8ebd
2015-06-12 16:00:30.736: Timeout waiting for seq=8ebe
2015-06-12 16:00:31.736: Timeout waiting for seq=8ebf
2015-06-12 16:00:31.736: Timeout waiting for seq=8ec0
2015-06-12 16:00:34.235: Timeout waiting for seq=8ec3
2015-06-12 16:00:34.235: Timeout waiting for seq=8ec4
2015-06-12 16:00:35.235: Timeout waiting for seq=8ec5
2015-06-12 16:00:35.235: Timeout waiting for seq=8ec6
2015-06-12 16:00:35.538: From x.x.x.x: bytes=60 SEQ=8eca TTL=254 ID=91be time=803.236ms
2015-06-12 16:00:35.538: From x.x.x.x: bytes=60 seq=8ecb TTL=254 ID=91f1 time=303.387ms
2015-06-12 16:00:36.235: Timeout waiting for seq=8ec7
2015-06-12 16:00:36.235: Timeout waiting for seq=8ec8
2015-06-12 16:00:37.235: Timeout waiting for seq=8ec9

 

Problem solver

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326 Messages

9 years ago

What modem are you using?

 

If you are renting one, make them replace the modem with a new Cisco if you don't have one already.

 

They increased the number of channels on the cable.  The old modems don't support all the channels so they are gradually replacing them as they need to.  By channels I mean data channels not TV channels.  That will eliminate the hardware as a potential source of trouble.

New Contributor

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4 Messages

9 years ago

What do your results look like after running: http://netalyzr.icsi.berkeley.edu/ ?

New Member

 • 

4 Messages

9 years ago

I had some kind of Ubee modem for a long time.  While diagnosing the last noisy-customer issue 2 months ago, the tech replaced my modem with an Arris CM820A.  These are intentionally the simpler modems without fancy features built into them (I manage NAT/wifi/etc from my own device), which is why I don't have a typical business modem.

 

Both the old and he new were Docsis 3.0 and I've never had any problem that was blamed on them.

 

I am a little surprised they haven't wanted to swap modem just to be sure.  From my perspective it seems unlikely the problems is on my side (modem malfunction the same day people cutting/fixing things over by the box outside? really?).  But I agree, after things being unusable last night I asked the next tech to bring a new modem and plan to run a temporarily line just to eliminate these fringe possibilities.

New Member

 • 

4 Messages

9 years ago

Everything green other than some trivialities (ports etc).

 

At this moment the issue is not evident though, no serious latency/drops since 4pm when it had problems for 30 seconds.  Maybe try the site again during heavy loss.

New Contributor

 • 

4 Messages

9 years ago

Can you tell me what the buffering measured as? I'm getting 1800ms of buffering on my downlink. =(