Welcome to Comcast Help & Support Forums
Find solutions, share knowledge, and get answers from customers and experts

New to the Community? Start here.

5,785,916

members

15

online now

1,936,553

discussions

Top

Phone serivce unusable when on internet

Contributor

Phone serivce unusable when on internet

I've been pretty satisfied with my Comcast phone service but noticed a problem today.  It seems that whenever I'm downloading or uploading on the internet my digital voice service becomes garbled like a cell phone with poor service. It is totally unusable.  I was able to test it by connecting directly to a slingbox at work.  Whenever I wasn't connected the voice was fine, as soon as I resumed the stream again the garbled voice returned.  I've reset the MTA with same results.  Any ideas?  Comcast claims that internet activity doesn't affect the voice side, but it sure seems like it does from what I've seen. 
Email Expert

Re: Phone serivce unusable when on internet

How are your power levels? See the sticky threads in the Connection forum for troubleshooting instructions.



Community Icon
I am not a Comcast employee, I am a paying customer just like you!
I am an XFINITY Forum Expert and I am here to help. For information on the program click here.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Mark it as an accepted solution!solution Icon
Community Icon
I am not a Comcast employee. I am a paying customer just like you!
I am an XFINITY Forum Expert and I am here to help.
We ask that you post publicly so people with similar questions may benefit.

Was your question answered? Mark it as an accepted solution!solution Icon
Community Icon
I am not a Comcast employee.

Was your question answered?
Mark it as a solution!solution Icon

Contributor

Re: Phone serivce unusable when on internet

yeah, seems like a weak signal to me...
 
do you have a splitter connected anywhere from where the cable comes into your house to the modem?  do you have a router connected?  how many set top boxes and/or tv's do you have connected to cable in the house?
 
any of these things will degrade the signal that much more...
Contributor

Re: Phone serivce unusable when on internet

Power level report from the MTA:
RF Parameters Downstream Frequency 555 MHz Power 2 dBmV Signal to Noise Ratio 34 dB Modulation QAM256 Upstream Frequency 30 MHz Power 52 dBmV
According to the FAQs the only problem is SNR is 34 nd FAQs say should be atleast 35.
 
Cable from comcast comes into a 2 way splitter, one leg into MTA one leg into Comcst supplied Dropamp. Dropamp feeds 2 six way splitters, all outputs are either connected to TV/cablebox or have terminator installed.  I have 2 cableboxes.
Frequent Visitor

Re: Phone serivce unusable when on internet

your snr is fine but the tx of 52 is out of spec it should be 50 or lower
Security Expert

Re: Phone serivce unusable when on internet



Anon3 wrote:
your snr is fine but the tx of 52 is out of spec it should be 50 or lower



Actually both are inside the limits, but are also very near them..
 
From Comcast:
 
Modem Signal Levels:
If the above steps have not resolved the connection issue, try viewing your modem’s status page and compare the signal levels to the following:
Downstream Power Level: -15dBmV to +15dBmV is the extreme limits that your modem should be able to operate within but ideally this should fall between -10dBmV and +10dBmV
Downstream Signal to Noise Ratio (SNR): This number is best over 35dB, but you may not have any problems with down to 33dB. Anything less and you will probably have slow transfers, dropped connections, etc.
Upstream Power Level: Ideally this should be within the 30dBmV to 50dBmV range. If it is between 50-55dBmV, you are approaching the upper-limits but should still be able to operate. If this is above 55dBmV or below 30dBmV, you will likely start to see frequent disconnects or modem reboots.
Upstream Signal to Noise Ratio (SNR): Anything above 29 is considered good. The higher this number is, the better. If this number is below 25 and 29, you have a minute amount of noise leaking in somewhere. If it's anything less than 25, you want to get it fixed as you may have a lot of packet loss or slow transfer rates. note: you will need to contact customer support to find out the value of this signal level as it is not available via the cable modem status page
Upstream Receive Power: Ideally this number should fall within the -10dBmV and +10dBmV range. note: you will need to contact customer support to find out the value of this signal level as it is not available via the cable modem status page

 
TANSTAAFL!!






Community Icon
I am not a Comcast employee, I am a paying customer just like you!
I am an XFINITY Forum Expert and I am here to help. For information on the program click here.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Mark it as an accepted solution!solution Icon

Community Icon
I am not a Comcast employee. I am a paying customer just like you!
I am an XFINITY Forum Expert and I am here to help.
We ask that you post publicly so people with similar questions may benefit.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Mark it as an accepted solution!solution Icon

Community Icon
I am not a Comcast employee.

Was your question answered?
Mark it as a solution!solution Icon