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bob-fairbairn asked bob-fairbairn commented

bufferbloat and VOIP

I am not sure if this is my problem but I have the feeling that it may be.  But check out http://www.bufferbloat.net 

I have been using VOIP (not RC) for quite a few years.  I still use voip.ms for my home phone and now RC for my business phone.  Sometime last year Comcast told us to replace our modem with a new one as the old one was "not supported"  Right after the modem was replaced I am pretty sure was the start of my VOIP problems.  When the uplink channel is busy VOIP gets messed up and outgoing voice chops, breaks up and is of lower quality.  Calm the uplink and all is ?OK? most of the time.  

So here I go getting signed up to be a RC partner and I install my system and of course it works better than voip.ms but it is still effected.  

Further training and research into routers and we decide that I should get a router with QOS.  Well RC has this nice list of either VERY EXPENSIVE or OLD routers.  (hey 802.11AC is here folks N is dead).  Anyway I get a Netgear R7000 because it appears to be close to what I need and has QOS.  RC has not updated their FAQ for newer router so I play and I have QOS turned on and it "may be better".  

I cannot sell this to my customers.  I cannot make it work for me.  Does Comcast Win?  Do I just chuck it in and go cellular?  

We will start another thread about routing issues......


RJF

PS Comcast 30mb x 5 mb low jitter VOIP testing says it will take 57 lines.

PPS with VOIP.MS and a OBHAI 202 router between the network and the cable modem I still get bad data.  


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8 Answers

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Chuck Fuscone avatar image
Chuck Fuscone answered bob-fairbairn commented
Hey Bob, I have been reselling for over 5 years and I always use Comcast business class if I can with my own routers and have not experienced anything like what you are saying.  Since the problem started with the modem change maybe that is the issue.,  Sounds like it is isolated to your internet install.

Just wanted to share my experience with comcast and Ring Central.  It has been a solid pair up

Chuck
Certified Ring Central Installer

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bob-fairbairn avatar image bob-fairbairn commented ·
http://bufferbloat.net  is worth reading
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bob-fairbairn avatar image
bob-fairbairn answered
Chuck,

What modem do you have comcast install?  
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Rich Brown avatar image
Rich Brown answered
The observation that voip goes bad during uploads is almost surely bufferbloat. Here's a great test:

Use  DSL Reports Speed Test - it's hands-down the best test for measuring bufferbloat.

If you see a latency/lag increase either when downloading or uploading, then your router is buffering more data than is useful.

I don't know specifically about your router, but there are a couple alternatives laid out in the Bufferbloat site at:  http://www.bufferbloat.net/projects/cerowrt/wiki/What_to_do_about_Bufferbloat  You can also get more background about bufferbloat at my blog:  http://richb-hanover.com/bufferbloat-and-the-ski-shop/

I would like to hear what you find.

PS Comcast has produced a spec (DOCSIS 3.1 - using the PIE algorithm) which will work nicely to reduce bufferbloat. Unfortunately, (a year later), I am not aware that they have begun to roll it out. So they know what to do, they just don't seem to be doing it.
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Rich Brown avatar image
Rich Brown answered
Actually, OSX is as bloated as anything else. (Regrettably, neither Microsoft nor Apple seems to have implemented the straightforward fq_codel algorithms for suppressing bufferbloat. SQM has been implemented in the Linux kernel for almost three years, and it's spreading from there.)

If you're willing to install a separate router, you can reclaim control of the bottleneck link (that's where bufferbloat occurs). CeroWrt used Netgear WNDR3800's, but these are becoming old, scarce, and expensive. Fortunately, all the fq_codel goodness has been pushed into the OpenWrt project, so you can buy any of a number of modern modems and still get the SQM/fq_codel benefits.

I am personally using a sub-$100 TP-Link Archer C7 v2 router that is well-supported with the stable OpenWrt release (Barrier Breaker code name). I install SQM/fq_codel according to the instructions at  http://wiki.openwrt.org/doc/howto/sqm

I would like to know the before & after results from http://dslreports.com/speedtest 
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bob-fairbairn avatar image
bob-fairbairn answered
OK this is getting closer to "root cause"  I  have a SB6141 that I THOUGHT was the right hardware to buy when comcast told me I had to take my old 5100 out.  So  I Just connected my MacPro 2013 to the modem directly using the router in the modem. I am getting 988/452 ms of buffer bloat on the line.  No wonder I cannot get VOIP to be happy or just about anything else.  I wonder if I get one of the routers that can take the cerowt firmware and get that going if it will calm this down or if I need a different modem too?


UGLY

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bob-fairbairn avatar image
bob-fairbairn answered
This reply was created from a merged topic originally titled Bufferbloat on small networks. Buffering in local network systems causing un-acceptable delays in traffic that causes a lot of network issues.  "bandwidth is not the be-all-end-all"

http://www.bufferbloat.net/news/54

https://www.youtube.com/watch?v=qbIozKVz73g
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bob-fairbairn answered
Status update.

Yesterday I received my TP-Link  Archer C7 AC1750 Router.  I started working with it this morning.  A quick install and setup with an update to their latest firmware.  I then ran the first network test from dsl reports:

<a href=" http://www.dslreports.com/speedtest/567875">;
<img src=" http://www.dslreports.com/speedtest/567875.png"></a>;


After that test I installed OpenWRT Buffer Breaker release firmware into the router.  Some basic setup and learning and a second test:

<a href=" http://www.dslreports.com/speedtest/567957">;
<img src=" http://www.dslreports.com/speedtest/567957.png"></a>;

After that test I enabled  SQM-Scripts  and setup the scripts to about 95% of my bandwidth in both directions.  Running the dslreports test:

<a href=" http://www.dslreports.com/speedtest/568163">;
<img src=" http://www.dslreports.com/speedtest/568163.png"></a>;

Now showing virtually no bloat!!

I loaded the outbound channel using Apple Photos uploading images to iCloud which totally saturates the outbound channel!  So I started my first VOIP testing using my home line that is on a OBI 202 to VOIP.MS.  During the first set of tests I found what I would call "perfect" received audio and the person I called said that my audio is great but there may have been a couple of words that had "edges" to them.  This load situation would have normally destroyed any out bound audio. 

I will be conducting tests with Ring Central and my polycom phone!





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bob-fairbairn answered
I ordered the TP=Link should have it mid-week will run before and after testing.  I sure hope this helps.  $100 experiment.
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