First post here. I am telling you this just so you realize that I have absolutely no clue what I am doing. But I do want to share some of my experiences with similar problems.
I have had ooma for over a year. In this time I have seen some of the same problems you are struggling with. At first I kept my landline just to make sure this 'ooma' thing was going to work out, especially since my landline provider (Horry Telephone Cooperative) does not allow people to 'port out' numbers. I had ooma for around 9 months (and was satisfied) before finally 'cutting the landline'. I have been happy with ooma for most of this time - my greatest problems have usually been at my end. I have had cable modems fail, line splitters die (I was genuinely surprised finding out how frequently cable line splitters fail - the service tech. replaced the 8 year old splitter out near the street and my signal improved ...well, you get the idea. So, except for the few times ooma service has gone down (2 that I remember, each for a short period of time), I have been happy with the service.
First - about the *99. I believe (translation - this is a blind stab in the dark) this changes how the ooma handles packets. If you want to send a fax using your ooma line you need to dial *99, you then get another dialtone and continue to do the fax as you would using a land line. If I do not dial *99 first my fax will fail, every time.
I have pondered what this 'magic' *99 does. Well, there is one thing that is most likely. Remember, the ooma system uses 'PUREVoice' or 'PUREVoice HD' if talking to another phone that supports it (
https://www.ooma.com/products/ooma-purevoice). This is some voice compression algorithm that 'reduces bandwidth consumption by 60% over standard VOIP technology'. It probably does this a number of ways - just think of how mp3s compress audio files by dropping non-audible frequencies and such. Well, when sending a fax (where the digital information is converted to analog sound and back on the other end) this is not very helpful. I am sure this compression is 'lossy' (just as a jpeg is 'lossy' vs. a png or gif). While it may be intelligible to you, it is not to a fax machine. I am willing to bet that *99 changes the settings to the voice compression and removes less information. There are a few other interesting 'clues'. When 10 digit dialing is enabled and you dial a 7 digit phone number, there is a slight delay while ooma 'decides' if you are done dialing. I think that I read somewhere that you don't get this delay if you dial *99 first (I have never bothered to confirm this). This makes me think that *99 makes other changes. It may reduce the packet size or 'force' the telo to send packets (even when they are not 'full' by reducing some timeout setting). This makes sense, because if the telo was waiting for enough data for whatever packet size it wants (with some type of timeout) it may not send your dialing information as quickly. There would also be nulls or places with NO audio in fax calls. By shortening the timeout (and forcing the telo to send packets) the dial would go through faster, faxes could also have no places without audio.
Well, enough of *99. On to router battles.
Yes, I have fought the good fight here too. First, my RoadRunner cable is not blessed with fantastic bandwidth. I have around 15 mb down and 0.37 mb up - my telo download is set in the 340K - 350K range right now. I used to have a Linksys router. I did everything imaginable to make the telo happy connected to it (QoS, setting ports, the works), but it was an ongoing struggle. There were times I would get a dialtone and not be able to dial out. My experience leads me to believe the telo generates the dialtone - it does so when it is 'connected' to the ooma servers. If I pick up the phone when the 'cable goes down' before the telo is aware of it - I get a dialtone - impossible if it is not generated at the telo. So getting a dialtone does nothing to indicate that outgoing packets will be handled correctly. I eventually ended up putting the telo between the router and cable modem. It was happy, life was good, but my pings were terrible (
http://www.pingtest.net/) for gaming. After a particularly memorible lightning storm I ended up with a Belkin Surf N150 modem. It is nowhere near as configurable as the Linksys was (no QoS support) but it was going after the telo so I did not care. Well, eventually I got sick of having good bandwidth but bad ping (and jitter) so I put the telo after the router a few weeks ago. I expected it not to work (based on everything I tried with the Linksys router) but - much to my surprise, I have had no problems so far. I have not tried using the phone while gaming yet, though. We all think of hardware (routers) as really fast - but I can't help but wonder about how the firmware was programmed and if packets were not being handled correctly by the other router. Perhaps the difference in router hardware (and firmware) plays a bigger role in all this then I want to admit. I never plan ahead to buy a router (router is dead - go get another one at wally-world now - working from home makes this a rushed decision). I may just take a look at the DD-WRT (open source router firmware) support list and proactively buy a supported router this time. Just wondering if proprietary firmware could be the 'wild card' here.
The other thing to note, as I said before, was to have your line checked. Since you have a much faster download then upload I suspect you have cable. Your bandwidth is much higher than mine (x green with envy x) , but I did not notice a great loss in bandwidth from the splitters failing. Nor did I see many more dropped packets - yes, I tested through speedtest.net and pingtest.net - but it definately affected the telo's performance. Since this was something I did not have access to (nor do I own that part of the line) I did not consider it. I think of splitters & connectors as 'passive components' - but, after all, passive components do (and can) fail. The tech told me splitters 'go bad' frequently (it's not like the contract installers are using 'top of the line' hardware all the time - they use what is provided) - he defined frequently as a typical lifespan of 5 - 10 years. I have not tried to confirm this - but next time I have problems I will be on the phone with them - I pay my bills - let them earn it.
There's my 2 cents. Back to work for me.