Ooma Forums

scottlindner wrote:What router are you using?

Dlink DIR-655. It provides QoS settings but there is no way to get a real time bandwidth chart like Tomato can apparently do.

scottlindner wrote:After this MTU thing I'm starting to suspect using Ooma as your router with DSL might be a bad call.

Unfortunately it won't do me any good to run in front of the router either. I'm on cable modem. No idea why my packet size is 1492, but I've tested and that's what it appears to be.

I seem to recall one of the ooma tech guys posted the bandwidth required but I can't seem to find the post now.

Obviously you still like it. I will give it a try and compare my experience with DD-WRT.

Is DD-WRT linux as well?
I'd like to pick up another router and try out DD-WRT, I have a non linux Linksys, (newer version) and of course Tomato won't work on it. It's hard to find down time on my network to be switching firmware, swapping out routers would be much better.

Wayne

Yes, it is Linux. One thing you could do is save your settings so it's fast and easy to restore. That is what I plan on doing. I wouldn't test a router without first pulling the other one out of service for my situation it's the same as having two routers.

I don't have any reason to believe DD-WRT is any better than Tomato.

Scott

On one of the other forums http://forums.ooma.com/viewtopic.php?f= ... s&start=30, Moderator Mojo stated

Mojo wrote:By default ooma uses 30 Kbps for each voice call.

I don't see why I'd have issues with 30k. Unless I'm doing real heavy uploads anyway, which is rare. Maybe I'm just overdoing the optimization.

Like I said, 48k is what ooma consistantly uses. I have an upload speed of 630 k (DSL) and I have no quality issues at all. Even if another call comes in, the second line quality is just as good. I have never measured 2 calls at once, but I'm going to assume it is twice the bandwidth.

Wayne

ggilman wrote:On one of the other forums http://forums.ooma.com/viewtopic.php?f= ... s&start=30, Moderator Mojo stated

Mojo wrote:By default ooma uses 30 Kbps for each voice call.

I don't see why I'd have issues with 30k. Unless I'm doing real heavy uploads anyway, which is rare. Maybe I'm just overdoing the optimization.

What type of ISP do you have (DSL, cable, other)? Recently I did a little test and found that Cable had worse QoS for VOIP than DSL. Not surprising. I also found an inverse relationship between QoS required for VOIP and max bandwidth. As you are saying, it's trivial amounts of data in comparison. I can't say my test was broad enough to use it as a cold hard fact, but it certainly opened my eyes to the differences between ISPs.

I also found that a single mistake in my router's QoS settings caused serious problems for my Ooma voice quality.

Scott

scottlindner wrote:

Colanth wrote:Wayne, considering that a single voice channel on POTS is capped at 48k, that 50k number (and the granularity of the graph) seems to be dead on where it should be.

Al

POTS is analog, not digital. Are you referring to the frequency range?
Scott

The bandwidth of the digital part of a voice channel on POTS (the POTS system went digital, except for the final mile, years ago) is 48k (on a 56k channel) to avoid crosstalk in copper. Or so the math-heads tell me. That would mean that, using their codecs, you can do anything that works on POTS in a 48kbps digital channel. Maybe I'm just missing something due to senility, but according to my way of thinking, we don't need more than 48k for voice (including SSTV, Fax, etc.) - *if* we use the POTS carriers' codecs. They're probably so weighted down with patents that it'll never happen, which is probably why VoIP needs more bandwidth for things like Fax.

All conjecture on my part, you understand - the ramblings of an old timer who learned about plate resistance in school, and had to bootstrap himself into the digital age.

Colanth wrote:

scottlindner wrote:

Colanth wrote:Wayne, considering that a single voice channel on POTS is capped at 48k, that 50k number (and the granularity of the graph) seems to be dead on where it should be.

Al

POTS is analog, not digital. Are you referring to the frequency range?
Scott

The bandwidth of the digital part of a voice channel on POTS (the POTS system went digital, except for the final mile, years ago) is 48k (on a 56k channel) to avoid crosstalk in copper. Or so the math-heads tell me. That would mean that, using their codecs, you can do anything that works on POTS in a 48kbps digital channel. Maybe I'm just missing something due to senility, but according to my way of thinking, we don't need more than 48k for voice (including SSTV, Fax, etc.) - *if* we use the POTS carriers' codecs. They're probably so weighted down with patents that it'll never happen, which is probably why VoIP needs more bandwidth for things like Fax.

All conjecture on my part, you understand - the ramblings of an old timer who learned about plate resistance in school, and had to bootstrap himself into the digital age.

I gotcha. So even though it isn't VOIP.. it's still VOIP-like.

scottlindner wrote:I gotcha. So even though it isn't VOIP.. it's still VOIP-like.

It's Vo<whatever addressing scheme they use>, maybe VoX25. I haven't seen the inside of a switching center since it was filled with Strowgers (any of you young kids even heard the term?)

Al