Solved: Re: Extremely slow upload speeds - Xfinity Help and Support Forums

ccfc1986 · ‎03-06-2018

I have recently come into an issue where my upload speed is pretty terrible. This has caused a number of issues for me as i work from home and perform many web conferences etc and need a consistent upload speed to do my job. I currently subscribe for the 300/25 service. My download speed is fantastic, it tests on both speedtest.xfinity.com and other 3rd party sites at or above 300mbps which is great. However, my upload speed is really tanking... i get about 6-8mbps through the xfinity speed test and less than 2mbps through 3rd party sources. This just isn't enough for me to do my job at home. Seeing as i pay for 25mbps i expect i would get at least 15mbps consistently, maybe less during busy hours. I have had a new cable modem, same problem. I had a technician come out and confirm some signal issues outside of the home (but related to the plant). Those issues were supposedly fixed last week - after power cycling all of my equipment i see the same issues with the upload speed. I even bought my own 3.1 docsis cable modem (Arris 8200) and this didn't solve the problem. I was able to do my job and stream data to other sites with no issues up until about 10-12 days ago. Now all my upload speeds are unbarable. I am hoping someonce can help me out. I am going to post some pics of my cable modem and the signals etc.

ccfc1986 · ‎03-06-2018

Tests i referenced with the slow upload speed. This is through testmy.net. I know this is a third party site and you can't necessarily rely on this...but this is pretty much accuate in what i am seeing to every single site. I can post twitch based bandwidth tests.

ArrisTuska · ‎03-06-2018

Going to send you a PM want to check the CMTS side..

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Network Engineer, IP Engineer, Docsis..; the views expressed on this post are mine and do not necessarily reflect the views of my employer..

Gamer.. Living the dream one catastrophe at a time

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ccfc1986 · ‎03-07-2018

The fact that i can connect to my phone 4g or my hotel wifi and get a better connection than what i am getting through you guys at Xfinity i find just laughable. Especially when i pay the amount of money that i do. If i lived 2 sub divisions over i could get gig speeds for half the cost. Whatever has happened to the network in my area (and i notice the guy above goes through some of the same backbones in your network as me) is causing problems. Again - this isn't a download speed problem - this is purely an UPLOAD speed issue. I would be happy getting less than 100mbps (even though i pay for 300) down if i could just get my upload speed even 50% of the way towards what i pay for (25mbps).

ccfc1986 · ‎03-07-2018

Running the same test i get similar results - not as much packet loss, but some....

|------------------------------------------------------------------------------------------|
|                                      WinMTR statistics                                   |
|                       Host              -   % | Sent | Recv | Best | Avrg | Wrst | Last |
|------------------------------------------------|------|------|------|------|------|------|
|                             192.168.1.1 -    0 |   87 |   87 |    0 |    0 |    8 |    0 |
|                             96.120.26.5 -    3 |   79 |   77 |    7 |   11 |   26 |    7 |
|                           68.85.208.113 -    3 |   79 |   77 |    7 |   11 |   26 |    8 |
|                          162.151.37.113 -    0 |   87 |   87 |    7 |   10 |   26 |    8 |
|be-124-ar01.elmhurst.il.chicago.comcast.net -    3 |   79 |   77 |    9 |   13 |   27 |   11 |
|be-33491-cr01.chicago.il.ibone.comcast.net -    3 |   79 |   77 |   10 |   15 |   28 |   15 |
|be-10506-cr02.350ecermak.il.ibone.comcast.net -    2 |   83 |   82 |   10 |   13 |   20 |   12 |
|be-10563-pe01.350ecermak.il.ibone.comcast.net -    2 |   83 |   82 |   10 |   12 |   18 |   11 |
|as40428-2-c.11greatoaks.ca.ibone.comcast.net -    3 |   79 |   77 |   10 |   13 |   28 |   15 |
|                   No response from host - 100 |   18 |    0 |    0 |    0 |    0 |    0 |
|                          216.239.42.154 -    3 |   79 |   77 |   12 |   18 |   33 |   17 |
|                           209.85.249.73 -    2 |   83 |   82 |   10 |   12 |   22 |   10 |
|              ord31s22-in-f238.1e100.net -    3 |   79 |   77 |   10 |   14 |   28 |   15 |
|________________________________________________|______|______|______|______|______|______|
   WinMTR v0.92 GPL V2 by Appnor MSP - Fully Managed Hosting & Cloud Provider

ccfc1986 · ‎03-10-2018

Here are my CM logs from the last ~12 hours:

3-10-2018, 10:43:17	Warning(5)	"MDD message timeout;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-10-2018, 10:26:11	Critical(3)	"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 14:31:42	Critical(3)	"No Ranging Response received - T3 time-out;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 14:31:3	Warning(5)	"MDD message timeout;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 14:30:52	Critical(3)	"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 13:8:23	Warning(5)	"TEK Invalid - Invalid Key Sequence Number;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 12:49:39	Critical(3)	"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:1:21	Notice(6)	"Honoring MDD; IP provisioning mode = IPv6"
1-1-1970, 0:1:7	Critical(3)	"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 9:38:14	Critical(3)	"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 9:2:2	Critical(3)	"No Ranging Response received - T3 time-out;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 8:59:2	Critical(3)	"SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 8:58:22	Critical(3)	"SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
3-9-2018, 8:57:40	Critical(3)	"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:01:5c:83:58:4d;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:4:26	Critical(3)	"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=2c:95:69:66:b3:9d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"

Here is my cable modem stats page:

Connection

The status listed show the connection state of the cable modem. They are used by your service provider to evaluate the operation of the cable modem.

Startup Procedure
Procedure	Status	Comment
Acquire Downstream Channel	513000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Configuration File	OK
Security	Enabled	BPI+
DOCSIS Network Access Enabled	Allowed

Downstream Bonded Channels
Channel ID	Lock Status	Modulation	Frequency	Power	SNR/MER	Corrected	Uncorrectables
1	Locked	QAM256	513000000 Hz	6.8 dBmV	36.6 dB	83677	60080
2	Locked	QAM256	519000000 Hz	6.8 dBmV	36.8 dB	96177	20272
3	Locked	QAM256	525000000 Hz	6.9 dBmV	36.8 dB	78367	12854
4	Locked	QAM256	531000000 Hz	6.9 dBmV	36.7 dB	57557	11087
5	Locked	QAM256	537000000 Hz	7.1 dBmV	36.9 dB	32095	10590
6	Locked	QAM256	543000000 Hz	6.9 dBmV	36.8 dB	27568	10451
7	Locked	QAM256	549000000 Hz	7.0 dBmV	36.8 dB	16044	10598
8	Locked	QAM256	555000000 Hz	7.0 dBmV	36.7 dB	14730	10934
9	Locked	QAM256	561000000 Hz	6.9 dBmV	36.7 dB	13555	11095
10	Locked	QAM256	567000000 Hz	7.1 dBmV	36.9 dB	6752	10384
11	Locked	QAM256	573000000 Hz	7.1 dBmV	37.0 dB	7380	9915
12	Locked	QAM256	579000000 Hz	7.1 dBmV	37.0 dB	6422	10956
13	Locked	QAM256	585000000 Hz	7.1 dBmV	36.9 dB	6321	11298
14	Locked	QAM256	591000000 Hz	7.1 dBmV	36.8 dB	6836	10677
15	Locked	QAM256	597000000 Hz	7.1 dBmV	36.8 dB	6589	11147
16	Locked	QAM256	603000000 Hz	7.1 dBmV	36.8 dB	6684	11543
17	Locked	QAM256	609000000 Hz	7.0 dBmV	36.8 dB	7593	11445
18	Locked	QAM256	615000000 Hz	7.0 dBmV	36.8 dB	6103	11278
19	Locked	QAM256	621000000 Hz	6.8 dBmV	37.0 dB	5756	10916
20	Locked	QAM256	627000000 Hz	6.7 dBmV	36.8 dB	6409	10948
21	Locked	QAM256	633000000 Hz	6.4 dBmV	36.7 dB	6527	10331
22	Locked	QAM256	639000000 Hz	6.3 dBmV	36.6 dB	6576	10157
23	Locked	QAM256	645000000 Hz	6.6 dBmV	36.8 dB	4557	11109
24	Locked	QAM256	651000000 Hz	6.6 dBmV	36.8 dB	4755	11002
26	Locked	QAM256	657000000 Hz	6.5 dBmV	36.7 dB	4198	11215
27	Locked	QAM256	663000000 Hz	6.5 dBmV	36.8 dB	4404	11556
28	Locked	QAM256	669000000 Hz	6.4 dBmV	36.9 dB	3904	11179
29	Locked	QAM256	675000000 Hz	6.5 dBmV	36.6 dB	6318	11014
25	Locked	Other	750000000 Hz	7.6 dBmV	35.2 dB	126544	0

Upstream Bonded Channels
Channel	Channel ID	Lock Status	US Channel Type	Frequency	Width	Power
1	60	Locked	SC-QAM	16600000 Hz	6400000 Hz	32.8 dBmV
2	57	Locked	SC-QAM	35800000 Hz	6400000 Hz	35.8 dBmV
3	58	Locked	SC-QAM	29400000 Hz	6400000 Hz	35.0 dBmV
4	59	Locked	SC-QAM	23000000 Hz	6400000 Hz	34.0 dBmV

Does anyone have any thoughts on this? I am still seeing the issue with terrible upload speeds - the download speeds are just fine. Any statistics or logs here jump out at you as a problem? My upload power is at or lower than the minimum power levels - that is all i can tell that might be slightly off.

Thanks!

The_Janitor · ‎03-10-2018

Is your modem connected to a splitter? If so what size splitter?

I am not a Comcast employee, just a moderator. Pls observe Wheaton's Law.

ccfc1986 · ‎03-10-2018

It was connected to a splitter when i had TV service as well. Since canceling i have seen this issue pretty much. I have since removed the splitter and now i have the cable in from outside directly connected to the cable modem. There are zero splitters between the outside->inside->cable modem.

Thanks

ccfc1986 · ‎03-10-2018

The issue has been resolved. I have no idea what they did - but a technican comfirmed i was getting some strange signal noise that may be impacting my upload speeds. He opened a plant ticket and said within 24/48 hours i should receive a phone call. I got a call this morning - and after doing an upload speed check i am getting 25/20mbps as expected. Thanks for all your support.