Ooma Hub's QoS - An Observation

[Groundhound]

I have my hub before my router, and I've enabled the hub's QoS with the following settings:
Upstream Internet Speed (Kbps): 768
Downstream Internet Speed (Kbps): 4500
Reserved Bandwidth for Calls (Kbps): 215

Out of curiosity, I ran a test while downloading a large file to see how those settings actually affected bandwidth. Prior to my test call the download was proceeding at a fairly steady 6500 Kbps. During my test call the download speed dropped to about 2600 Kbps, a lot more than I expected given the QoS settings above. The call quality was excellent in both directions. It would seem though, that the “Reserved Bandwidth” setting is off by more than a factor of 10.


Call quality is much more important to me than download speed during a call, so it's more of a curiosity than a problem at this point. I've considered putting the hub behind my router, but the Tomato firmware does not do a good job of prioritizing download bandwidth according to the Wikibooks linked from the Polarcloud site: http://en.wikibooks.org/wiki/Tomato_Fir ... _.28QoS.29
“This is primarily useful for outbound data (data going from your computers to the Internet). Inbound data cannot be prioritized effectively because it has already passed through the bottleneck (your Internet connection) by the time the router has a chance to evaluate it.”

So I'd like to see a comment by someone in the know at ooma about the QoS settings and their actual effect on bandwidth. Is this the way it's supposed to work, or are these settings still a beta feature with changes yet to come?

[WayneDsr]

I know this is not what you're asking, but I have Tomato firmware on my Linksys and it does an awesome job of QOS. I have no issues with ooma including downloading/uploading during a call.

Wayne

[Groundhound]

Another concern for letting the router handle QoS is the fact that QoS is on all the time. Since I have Comcast as my ISP, it would effectively kill the Powerboost feature unless I set the QoS limit artificially high which kinda defeats the purpose of it. Another quote from the Tomato wiki:
"QoS works by having fixed maximum inbound and outbound bandwidths, and then allocating that bandwidth based on packet priorities. This means that the firmware will NEVER allow more than the configured bandwidths. Even if your service provider allows more (either temporarily as a "speed boost" feature, or permanently as a service upgrade) you will still be restricted to the configured bandwidth. If you need the highest possible bandwidth at all times you may wish to leave QoS disabled."

I like that the hub's QoS steps out of the way when there is no call in progress.

[scottlindner]

I have observed the same behavior. I have two theories.
1. It is simple math based on the QoS settings for each level. Assuming you are using Highest Priority the single line of Ooma is using less than the reserved amount for the Highest Priority.
2. It is more advanced and the QoS algorithm needs to reduce the upstream in order to guarantee delivery in order for each priority level.

I suspect it's theory #1 which means you can tweak the QoS level thresholds to optimize your exact situation. On my Tomato QoS setup the Highest level is given 80-100%, (520 - 650 kbit/s). That is 130kbps bandwidth range. Since one line of Ooma uses 48kbps would that mean when there is highest priority traffic there is 82kbps that is left unused?

As for the comment about the Hub turning QoS off when a call is done, you should be able to do this with a simple command line change in Tomato. I have read about it on the DD-WRT forums. People do very complex things via command line with very simple one liners. I don't completely get it, but since both Tomato and DD-WRT are built using mostly the same source code you should be able to easily find the answer to this question on the DD-WRT forums.

I am also curious how QoS would affect your speed boost. Isn't that for download only? The QoS settings we are setting on Tomato are for upstream only, leaving the downstream completely altered.

Scott

[Groundhound]

I am also curious how QoS would affect your speed boost. Isn't that for download only? The QoS settings we are setting on Tomato are for upstream only, leaving the downstream completely altered.

It's both ways, my speed tier is 6000 down 1000 up but the Powerboost temporarily increases both:

[scottlindner]

I understand the issue now. I think you'll need to figure out a command line hack to disable QoS during Ooma calls. I'd try the DD-WRT forums since there aren't Tomato forums.

Good luck and let us know what you find out!

Cheers,
Scott

[Groundhound]

Well, since I don't have a compelling reason to put the hub behind the router for now, I'll probably wait and see what the ooma folks say about the hub's QoS.

[scottlindner]

Well, since I don't have a compelling reason to put the hub behind the router for now, I'll probably wait and see what the ooma folks say about the hub's QoS.

I believe people feel it works well enough for maintaining your call quality. If that is all you care about and don't care about prioritizing online gaming, I think putting the Ooma Hub first is ideal.

If that's the case, do you even need your router at all? Doesn't the Ooma Hub also provide NAT and DHCP server?

Cheers,
Scott

[Groundhound]

If that's the case, do you even need your router at all? Doesn't the Ooma Hub also provide NAT and DHCP server?

Still need it as it provides wireless AP plus WDS link to two other Linksys WRT54G's in my house.

[scottlindner]

If that's the case, do you even need your router at all? Doesn't the Ooma Hub also provide NAT and DHCP server?

Still need it as it provides wireless AP plus WDS link to two other Linksys WRT54G's in my house.

I don't know what WDS is, but you can configure an wireless router to be an WAP only. That is what I have done with one of my routers so it's a dumb access point. Is it possible that WDS can be treated the same way, or do you need the NAT and DHCP in all routers?

Scott