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Engineering Help with T3/Packet Loss/Upstream Issues

Regular Contributor

Engineering Help with T3/Packet Loss/Upstream Issues

I guess this is my 'hitting my limit' or 'wits end' post ... but I really think I may need some Comcast engineering support with an ongoing node / upstream noise issue I've been dealing with for a couple months.

 

Background:

I'm outside Philly, and back in mid-January after some record cold temps and high winds I started running into connection issues.  This wasn't my 1st time seeing these issues over the years, and I suspected upstream noise problems.  Modem and X1 singals looked fine, but I was getting intermittent bouts of packet loss and T3 errors on my modem.  After muliple tech visits, calls to Tier 2 support and getting through to local supervisors they confirmed upstream noise issues on my node and said there was a lot of noise in my nieghborhood.   I had multiple tech visits confirming the noise in my area and a local supervisor even sent an outside and inside tech to confirm everything at my house was noise free and my equipment was OK.   Atfer cleaning up the noise over a few weeks in my area, my problems cleared and everything was great by the end of February ... or so I thought.

 

NOW:

Around 3/15 - 3/16 we had very high winds and some storms come through.  All the lines in my area are above ground.  Around that time I noticed my problems had retuned.  Equipment wise I have an Arris XG1v3 box and an Arris SB6183 modem hardwired via an ASUS AC1750 router.  I would start to notice the guide and menus lag, freeze, or miss inputs on my X1 box.  On my internet I would get webpages freezing and skype call were cutting out.  Speed tests would have the upload jump all over the place.  My modem signal looked fine while the issues were occuring, and I know how to check the DOCSIS levels on my X1 box, and they were fine as well.

Of coruse my modem logs were clean EXCEPT for T3 errors that will update frequently when issues are occuring.  If I run ping tests to google, gmail, my 1st comcast hop etc. I also see sporatic burts of frequent pack loss.

On 3/16 while I was suffering a bout of these issues I called Comcast and struggled to finally get through to TIER 2 support.  They confirmed that while all my singals initially looked to be in the 'green' they continued to update my signal checks and could watch my upstream noise or singal quality jump from 32 down to 25 and then back into the green.  The tech ran packet checks and saw them jumping from great down to 13-18% packet loss.  Basically the tech confirmed there was upstream problems and said a tech had to visit.

On 3/17 yet another tech visited my hoouse and confirmed like all the others that was nothing wrong with my house or equipment.  Later that day when the issues returned I pushed through to Tier 2 support who ran a 'proximity check' and showed 'line errors' on my street pointing to the ongoing signal issues and said my upstream noise was boucing between 25 and 28.

I've had a few days in a row where I won't have any issues and will not see a single T3 error in my logs.  But then for several days in a row it will run into the intermittent packet loss and T3s again.

Over the past weeks the Xfinity Status map is always showing outages popping up daily in and around my area.  Yesterday on 3/25 almost my entire area was experiencing outages, and when they were cleared, the T3 / packet loss had stopped for the rest of the day ... only for it to return sometime overnight as I was already seeing T3 errors this morning after I noticed my X1 box menu was slow to respond.  When I called into tech support yesterday they noticed everything was in the green, but my upstream noise was 28.  I though 28 was low, but they said that value was OK?

 

The local techs I've worked with have been very good and a local supervisor I reached out to was going to look into the situation, but I don't know if I'm getting anywhere?  Being an intermittent issue I'm not sure if things are being monitored when the problems are occuring.

 

Is there any way I can get Comcast engineering the help with this issue?  This is well beyond the swap equipment and reboot the modem.  As I mentioned I've had multiple tech visits over the past couple months and the techs have seen the usptream quality or line issue when my problems are occuring.  Just for the heck of it, here were my singals this morning when I was running into problems again:

 

Downstream Bonded Channels

Channel

Lock Status

Modulation

Channel ID

Frequency

Power

SNR

Corrected

Uncorrectables

1

Locked

QAM256

1

489000000 Hz

7.3 dBmV

41.9 dB

0

0

2

Locked

QAM256

2

495000000 Hz

7.3 dBmV

42.0 dB

0

0

3

Locked

QAM256

10

555000000 Hz

6.4 dBmV

41.8 dB

0

0

4

Locked

QAM256

11

561000000 Hz

5.9 dBmV

41.6 dB

0

0

5

Locked

QAM256

16

591000000 Hz

5.5 dBmV

41.4 dB

0

0

6

Locked

QAM256

17

597000000 Hz

5.8 dBmV

41.9 dB

0

0

7

Locked

QAM256

18

603000000 Hz

5.8 dBmV

41.9 dB

0

0

8

Locked

QAM256

20

615000000 Hz

5.4 dBmV

41.6 dB

0

0

9

Locked

QAM256

21

621000000 Hz

5.4 dBmV

41.6 dB

0

0

10

Locked

QAM256

22

627000000 Hz

5.3 dBmV

41.6 dB

0

0

11

Locked

QAM256

23

633000000 Hz

4.8 dBmV

40.9 dB

0

0

12

Locked

QAM256

24

639000000 Hz

4.8 dBmV

40.9 dB

0

0

13

Locked

QAM256

27

651000000 Hz

4.9 dBmV

41.1 dB

0

0

14

Locked

QAM256

28

657000000 Hz

4.4 dBmV

40.8 dB

0

0

15

Locked

QAM256

29

663000000 Hz

4.4 dBmV

40.8 dB

0

0

16

Locked

QAM256

30

669000000 Hz

4.9 dBmV

41.2 dB

0

0

 

Upstream Bonded Channels

Channel

Lock Status

US Channel Type

Channel ID

Symbol Rate

Frequency

Power

1

Locked

ATDMA

7

5120 Ksym/sec

23700000 Hz

41.0 dBmV

2

Locked

ATDMA

5

5120 Ksym/sec

36500000 Hz

42.8 dBmV

3

Locked

ATDMA

6

5120 Ksym/sec

30100000 Hz

42.3 dBmV

4

Locked

ATDMA

8

5120 Ksym/sec

17300000 Hz

40.3 dBmV

 

Everything is in spec.  The only thing I have in my modem log is:

No Ranging Response received - T3 time-out

And that will update ~ every 5 to 20 minutes along with frequent packet loss when the problems are occuring

 

This isn't my 1st rodeo dealing with these noise issues, but this may be the worst imterminnet issue I've dealt with in years.  Can anybody from Comcast help with figuring out what's going on in my nieghborhood or node?

 

Also, the last few times I've called to get my uSNR when the pack loss was occuring, they were reporting values of ~ 27-28 and saying that's in the 'green'?  I thought those values are low?  When the problems aren't occuring they've reported values ~ 31-24

 

 

Regular Contributor

Re: Engineering Help with T3/Packet Loss/Upstream Issues

Don't know if this helps, but as an update I was able to get throught to an Advanced Repair Tech (tier 3?) this afternoon, as my noise issues were getting pretty bad.  He was able to look at my singal history and confirm the upstream noise issue and see it corresponding to my signal issues over the past couple weeks.  He mentioned he could see the upstream degrade on and off over the past week and it was currently sitting at 26.

In fact while I was seeing the problems today he mentioned that 'noise outages' were being triggered in his system and expanding over my area during the afternoon.  For now I need to have yet another tech visit, but I understand if it helps keeping the troubleshooting moving, then I'm willing to help out as well.  He also created a ticket to track all the info he collected.

I really do appreciate all the work the techs have been helping with, even though this is just getting maddening ... but I need stay persistent, patient (and polite)

 

Official Employee

Re: Engineering Help with T3/Packet Loss/Upstream Issues

Hi Brocktoon, I have responded to your private message.

 

Thank you 


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Official Employee

Re: Engineering Help with T3/Packet Loss/Upstream Issues

Hi Brocktoon, thank you for working with me through private message and please reach back out if you need assistance in the future.

 

Thank you 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!