Bandwidth Question

[gregorygso]

I have been with VOIPo for about a month now, and recently noticed something that I would like comments regarding. I have what I call the standard configuration (cable modem >> Linksys RT31P2 >> Dlink DGL-4100 >> LAN.) When sending (uploading) files, I noticed my upload speed reduced to 20% when I have an active call on port 1 (no phone on port 2.) I did speed tests through DSL Reports site and here's what I observed on average (rounding my figures, but the ratio is the same.) Average download speed 5MB and average upload speed 500KB with no active call. Average download speed 5MB and upload of 100KB with an active call. I performed the test over several test locations and got the same general results. So, when I have an active call, the telephone adapter is carving out about 80% of my upload bandwidth for the call. This seems excessive to me. I had CallVantage for over 4 years (until they discontinued the service and I choose VOIPo) and never noticed such an excessive reduction. As a matter of fact, perceived file transfer perfomance is the same between VOIPo and CV with no active call. I was under the impression the average bandwidth to reserve for voice calls was around 100KB. So, where is my other 300KB going? Are my tests legitimate? Do I have a configuration issue? If this is normal, is there a setting where the voice bandwidth can be reduced somewhat (yes, I understand call quality and bandwidth are related) and find an accptable middle ground?

Thanks for your thoughts.

Richard.

[fisamo]

When you had CAllVantage, did you have the same setup?

Modem --> ATA --> Personal Router --> PCs/other network devices

Also, what's your upstream bandwidth typically (with no call), 500k? (Perhaps you mentioned it in your post, but I missed it.)

I'm not familiar with the RT31P2, but if you have a VoIP ATA as the first device in line from the modem, it can seriously throttle your traffic, if that's what it's programmed to do. In a way it's funny you mentioned ATTCV, because their DLink DVG1120M was notorious (especially early in the service when that was the only ATA they offered) for throttling people's connections...

Here's what I recommend that you consider, but it does depend if your router has QoS capabilities. (If not, you may not want to switch your network around.) Put your router directly to your modem, then plug your ATA into one of the router's LAN ports. Set your ATA to have highest-priority QoS.

Once in that setup, place a test call to a reliable destination (e.g. a friend who will tell you if your phone connection is good or bad), and start a 2-way speed test (e.g. at dslreports.com). If the upload speed is improved relative to what you're seeing on the phone now, start uploading a folder full of 5MP-or-greater pictures to Snapfish, and ask your friend how you sound. If you like the answer, keep this setup.

[kbuck320]

Honestly, I'd be happy to have the router's QoS being aggressive, demanding more than enough for the PAP2.

I mean, how often are you maxing your upload while making phone calls? I suppose if you are running a server with high load, or doing p2p file sharing .. 100k upload is still more than plenty for web surfing and the like.

[Warus1]

I was just about to post a question along the same lines, please don't think i'm trying to hi-jack the thread.

I have the VOIPo Linksys PAP2 TA, it does not have a LAN port, so the only choice is to put it behind the router.
I'd prefer to have it in front of the router to ensure the needed bandwidth always goes to the TA.

Is there any way to configure this TA to grab the max bandwidth or it is router dependent? If router dependent, any one know how this is accomplished?

[burris]

If your router has a decent QOS function, you can try setting it for VOIP priority within the limits of your upstream bandwidth..

[gregorygso]

Thanks for the comments. And now my responses:

Fisamo: Yes, my download is 500KB phone call or no phone call. Unfortunatelay, none of my equipment has any "user settings" for QoS. The router manual says it "automatically adjusts QoS for maximum quality"... sounds redundant to me! I may move my network around just to see what happens. Seems like when I first got CV, I called them up and had them make an adjustment on the bandwidth for this same reason, but that was years ago.

Kbuck320: I agree that in the big scheme of things, this isn't noticable very often, as I currently only move large audio files on Sunday afternoon when I upload material to the church's websever. I noticed it a couple weeks ago when I was on a long call, and trying to upload files at the same time. What normally took 15 minutes took over an hour. And to be understanding to VOIPo, I would carve out as big a chuck as I could to get my voice quality up, and I'll admit there are no complains about the current voice quality whatsoever. I was just curious if there was a "lower" setting in ATA they provided so I could use my bandwidth a little more efficently. I have a project down the road where I hope to serve two-way radio audio, and was thinking ahead.

Unrelated, and maybe not, I've had to reset my Linksys 31P2 twice recently (Thursday afternoon and again this morning) due to no internet access. The Phone 1 & 2 lights are dark, but everything else "looks" OK. I pulled out my wireless LAN card, got on my control panel, and when checking devices, it says "I have no devices registered!" Recycling the power on the 31P2 resolved my problem both times. I intend to put in a trouble ticket on this later today. I imagine I'll be talking to someone about my reset issue, and I'll ask them about my bandwidth question also.

Thanks, Richard.

[VOIPoJustin]

We use the G.711 codec, which for VoIP will give the best overall quality.

Since it uses no compression and is essentially the same codec used by the PSTN network and ISDN lines, it sounds just like using a regular or ISDN phone. It also has the lowest latency (lag) because there is no need for compression.

From a bandwidth perspective, it can use up to 84kbps (when you factor in all TCP/IP overhead).

[gregorygso]

Thanks for all the replies. When I called support to inquire about my lockup issues (which were quickly handled), I also got the info I needed to deal with my bandwidth situtation. For those that are curious, the Linksys RT31P2 ships with a default voice bandwidth setting of 256KB. I'm currently experimenting with a setting that works best for my requirements.

Richard.