This forum includes tips for maintaining the best audio quality possible with the Ooma System. If your Ooma system is having issues with dropped calls, static audio or echo, look here for assistance.
#86245 by Charles R
Sun Aug 21, 2011 6:23 pm
I started a thread named Call Quality Poll where one can relativity rate their call quality via Ooma. Here I'm trying to solve some confusion I have regarding the various issues revolving around call quality. As an example I have seen similar to this posted on several occasions.

The delay problem is an individual problem. If you don't contact Ooma with your delay problem it will never be corrected. You also have to get to higher levels of support for corrections to be made. You also have to be persistent and respectfully keep after Ooma Support to get you delay problem solved.

As background my experience with using Ooma is only a couple of weeks and a few dozen calls. Certainly not enough to draw any solid conclusions but I have drawn a few regardless. I do have plenty of bandwidth available and I have installed the Telo on two Internet lines (for comparisons).

- Local calls: overall work rather nicely.
- Long distance: hit or miss. A good percentage of time static, delays and generally a bad connection I never saw with my landline.

My confusion is in a couple of areas. SInce I have never experienced these issues with my landline I'm presuming the issues are a result of the Ooma service. Possible confusions...

- If I have enough free bandwidth there is nothing I can do to tweak and or improve the quality.
- What exactly causes call quality issues?
- Why would one need to have Ooma work on your account to resolve issues?
- Why wouldn't all of these possible resolutions be applied on a global basis?

I have a good understanding of the Internet and how it relates to data transfer so my confusion is how its related to call quality and how various issues can be addressed. I'm trying to get enough of an understanding to determine whether I should go down the path to improving my call quality or simply accept it is what it is.
#86260 by murphy
Mon Aug 22, 2011 6:39 am
Packets being dropped or arriving out of order is the biggest problem with VOIP. There is some tolerance for out of order packets but they longer they wait for a missing packet the longer the voice delay will be. If a packet arrives after the cutoff point it has to be discarded. Missing packets reduce the audio quality.

VOIP is not like a TCP connection where out of order packets can be put back into the right order before the file is saved.
#86318 by Charles R
Tue Aug 23, 2011 10:57 am
This is what a call from my wife to her sister looks like. :) I'm surprised I haven't run across this yet... but why is the outgoing (green) bandwidth roughly three times the incoming (blue)? The call was placed with the Telo behind my DSU/CSU (more or less a router).

Regarding packets...

  • I presume the Telo converts the local analog audio to digital and then transmits the data?
  • How/where is the remote analog audio converted to digital?
  • Once received the Telo converts the remote caller's digital audio to analog?
  • How does the local digital audio (converted from analog) get converted back to analog for the remote called to hear?
As you can see I have no understanding how any of this works and I think it would be helpful to have an overview posted somewhere. I'm sure there is... anyone have a link?
Attachments
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#86334 by DTR
Tue Aug 23, 2011 6:47 pm
You can study the Protocols (mainly SIP) in the link Murphy provided to get an understanding of the call setup and sequencing. SIP is one of the more common protocols for VoIP.

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