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pepi3
join:2013-02-26
Hartford City, IN

pepi3 to ptrowski

Member

to ptrowski

Re: Comcast Jitter

Now, here is something else I forgot. I had Comcast Voice before and bought a OBi unit. I had both hooked up and both were working great. When I called Comcast and had them remove my Voice that's when it all when south. I've tried GoogleVoice and CALLCentric with the same results. I took my OBi box to my nephews home with DSL and it works fine.

And yes, I've reset everything without any luck. I've also tried two different cable modems and two different wireless routers.

Thanks guys!

EG
The wings of love
Premium Member
join:2006-11-18
Union, NJ

EG to kdouglas10

Premium Member

to kdouglas10
said by kdouglas10:

If none of that helps, then back to what pflog sez re: S/N ratio. My Comcast tech (who rolled out here 3 times to get my S/N above -37db & finally ran an amplified "homerun" from my distribution box) swears that -37db is a **minimum** signal for reasonably reliable speeds and video streaming.

FWIW, pflog See Profile was referring to the "uSNR" (upstream Signal to Noise Ratio). Even if the downstream (forward path) SNR looks good and is in spec, there may be noise ingress in only the upstream (return path) carrier/s operating frequency range.
CplEstesUSMC
join:2005-02-16
Douglasville, GA

CplEstesUSMC to pepi3

Member

to pepi3
So I opened your docx and found that you have no packet loss but you have "discards" I can only guess the difference is that discards are packets that have been rejected by the network due to congestion. If this is the case then powerboost might be your culprit as I have troubleshot something similar with Skype.

One thing to try is to rate-limit your upstream based on what you know to be your sustained upstream, ie 16/2 or 25/4 50/10 This will stop any application from infringing on the upstream "excessive burst" zone of the powerboost rule and the successive discards to follow after the excess token bucket has been exhausted.

Please let me know if I'm accurate on the test's definition of discards and of course let me know if this helps.
pepi3
join:2013-02-26
Hartford City, IN

pepi3

Member

"One thing to try is to rate-limit your upstream based on what you know to be your sustained upstream, ie 16/2 or 25/4 50/10 This will stop any application from infringing on the upstream "excessive burst" zone of the powerboost rule and the successive discards to follow after the excess token bucket has been exhausted."

Not sure how to do this ??? Not real up on network stuff.
voiptalk
join:2010-04-10
Gainesville, VA
MikroTik RB750G
Cisco DPC3941

voiptalk to ptrowski

Member

to ptrowski
said by ptrowski:

Given that it is your voice breaking up I would tend to think you should set up some qos. Typically that is an upload issue. Are you or the family doing anything bandwidth intensive at the time?

I agree, that's where you need to look first.

If you go and look at the graphs/test results. It clearly shows "Bandwidth probably too low ....", packet discards and all the jitter is on the upstream. That's a classic indication of the upstream data getting clobbered, the RTP stream is competing for too little bandwidth.

It looks to me like the jitter is being introduced locally by your router as packets are buffered as they are exiting the WAN interface. That's not a Comcast/network problem.
pepi3
join:2013-02-26
Hartford City, IN

pepi3

Member

I've been through 3 different cable modems and two different wireless routers. I also get the nasty Jitter signals when I do my test directly into the cable modem. Two ARRIS modems and now a Zoom 5341J with the exact same results on Jitter. The otherday for some reason my VoIP tests were all in the green. I called a few people on my phone and they said it sounded great. Later that evening back into the yellow and red and my phone was cutting out on my end again.

I tried setting up the QoS on my linksys wireless router and it doesn't seem to make any difference?
pepi3

pepi3

Member

I was also told that maybe my upload has too much noise on it?

Upstream Bonded ChannelsChannel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 7 5120 Ksym/sec 31600000 Hz 35.5 dBmV
2 Locked TDMA 1 2560 Ksym/sec 37500000 Hz 37.0 dBmV
3 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
4 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV

gar187er
I DID this for a living
join:2006-06-24
Seattle, WA

gar187er

Member

this is upstream signal to noise, and can only be read from the CMTS,not from the house.
CplEstesUSMC
join:2005-02-16
Douglasville, GA

CplEstesUSMC to pepi3

Member

to pepi3
Completely depends on your router, if you can get ahold of an IOS device than I may be able to send you some commands. I know an ASUS rt-n66u can do this. There maybe something in DD-wrt or tomato as well.