Optimum QoS Question

[EA PA]

After running some diagnostics through the week, I have determined that my upload speed is 493 kbps. The OOMA default in setup.ooma.com for QoS was 384 kbps I believe. An article in OOMA support titled Configuring Quality of Service recommends setting QoS to 15 to 20% less than measured upload speed. My question is; does experience demonstrate that this 15 or 20% less than measured is actually optimum? If not, what % of upload speed seems to be the best setting?

Thanks

[thunderbird]

After running some diagnostics through the week, I have determined that my upload speed is 493 kbps. The OOMA default in setup.ooma.com for QoS was 384 kbps I believe. An article in OOMA support titled Configuring Quality of Service recommends setting QoS to 15 to 20% less than measured upload speed. My question is; does experience demonstrate that this 15 or 20% less than measured is actually optimum? If not, what % of upload speed seems to be the best setting?
Thanks

15 to 20% is more a rule of thumb. If you aren't having any problems, don't change anything. Otherwise make small adjustments and try it to see if conditions improve or become worse. Make Adjustment accordingly.

[EA PA]

Thunderbird - OK thanks - I still get about 10% of OB calls with issues. I tweeked it up to 420 kbps. Will try tomorrow when there is some traffic. I did notice that the upload speed drop to about 270 kbps with OOMA in use, I would expect a decrease while testing with OOMA in use - would you agree? Thanks

[thunderbird]

Thunderbird - OK thanks - I still get about 10% of OB calls with issues. I tweeked it up to 420 kbps. Will try tomorrow when there is some traffic. I did notice that the upload speed drop to about 270 kbps with OOMA in use, I would expect a decrease while testing with OOMA in use - would you agree? Thanks

With Ooma in use with activated QoS settings, you are "protecting bandwidth" for the Ooma device, so yes the bandwidth as measured from you computer behind the Ooma device will decrease.

[EA PA]

I read its like 130 but the math did not add up - 490 vs 270 is about 220. Is the protected area adjustable in the OOMA telo?

[thunderbird]

I tweeked it up to 420 kbps.

The 420 kbps that you entered is the "protected" or reserved bandwidth for the Ooma device when it is in use.

[EA PA]

Thunderbird, this is the basis of my question - note the 130 kbps setting quoted - hence my questions, and confusion .... your explanation makes more sense but this is out of the OOMA support documentation

http://ooma.custhelp.com/app/answers/de ... /related/1

[thunderbird]

http://ooma.custhelp.com/app/answers/de ... /related/1

The Ooma support document above says that there are packets dropped during certain QoS settings. So to test, I reconfigured my setup, and tested, with my Ooma phone in service, connected to my cell phone. I tested using a computer connected the Ooma Telo home port using http://speedtest.phonepower.com/.

Not once did I see lost or dropped packets, with Ooma configured as shown in the diagrams.

Maybe the Ooma description of what happens with different QoS settings, is really just a high level overview, and not detailed enough to explain everything?

[EA PA]

There are actually 2 articles in the support section. The first titled "configuring quality of service" and the second titled "learning more about OOMA QoS". The former states that you should measure the upload speed and enter this speed into the setup. The later says use 15 to 20% less as an optimum setting for some reason.

After a review of the Learning More... doc, I suspect that what they depict in scenario 1 is that when QoS is equal to or slightly less than measured upload speed, it is possible to lose some network packets when uploading data through the OOMA when in use due to the firmware coded 130 kbps "reserved" area limiting the normal non OOMA throughput. This is in the Modem - OOMA - router configuration.

If you notice in the diagram, there are 4 areas shaded - reserved, data traffic, QoS bandwidth and upload bandwidth. My guess is these 4 shaded areas are 130 kbps coded OOMA, data traffic (simply the balance of upload bandwidth), QoS (entered in the setup area), and finally measured upload speed. Therefore, what you are setting in OOMA setup is basically a match to upload speed (QoS).

In scenario 2, with QoS lower than measured upload speed, it still maintans the 130 kbps, but reduces upload data traffic bandwidth accordingly - so once again packet loss occurs with data.

Scenario 3 shows that QoS greater than upload speed and therefore it loses packets of voice and data as it opens throughput but gets chocked at the modem due to limits in upload speed. I suspect that if QoS is raised high enough above the measured upload speed, and upload traffic is increased with voice and data, both voice and data packets will be lost.

My interpretation here but seems to make sense. Anyway my take away is what they really want is the upload speed to be as close to QoS as possible without going over - essentially tuning the OOMA to the internet. This is supported by the first document above as well... I am not exactly sure why they did this. If QoS function actually took highest priority, there would be no need for this.

To make sure, I contacted OOMA for clarification and they indicate below that it is the measured upload speed that they want in the setup. This post is edited to add the email response for future readers.

________________

Dear OOMA User,

Thank you for contacting Ooma Customer Care.

I'm sorry for some confusion. Quality of Service - QoS works by allocating a portion of your total available bandwidth to Ooma services, including phone calling and voicemail playback. In order for QoS to work properly, it needs to know what your Internet speed is in the upstream direction.

Many home routers and other Voice over IP adapters claim to have QoS capabilities built into them, but most do a poor job of implementing packet prioritization. One of the main reasons QoS just doesn't work well on these other platforms is they do a bad job at guessing what the true upstream bandwidth is. Most of these other devices also don't provide an option to set what your upstream bandwidth actually is.

If you have further questions or require additional clarification, please write me back and I will respond to you as quickly as possible, usually the same day. Your satisfaction is important to me, and I will make sure we bring this to resolution consistent with your expectations. If it’s more convenient, you can also visit our support website https://www.ooma.com/support and check out our wide variety of helpful articles that may answer any additional questions that might come up in the future.

Thank you for choosing Ooma!


Sincerely,

John

Ooma Customer Care Specialist

[EA PA]

And by the way, based on the last post, my QoS is now set a few % less than the measured - 480 kbps vs 490 measured. I am currently not seeing any of the issues that are being posted - it may not be this with all of the firmware rollouts and other fixes being implemented. I will really put it through its paces next week and post results.