[voip247]

Just how effective is the QoS on the SPA-2100? In my testing, it works very well on a 384 kbps uplink, but NOT well at all on a 128 kbps uplink. That is, when I simultaneously ran the "Upload Speed Test" at http://performance.toast.net (which saturates my uplink for about 30-60 seconds), I didn't hear any voice problems on the 384 kbps uplink, but voice sounded tinny and had many clipped sounds on a 128 kbps uplink.

For both networks, I didn't hear any voice problems when I wasn't running the "Upload Speed Test", so I'm confident that it's a Sipura issue rather than a network issue. My initial settings were QoS QDisc = TBF and Maximum Uplink Speed = 384 (for the 384 kbps uplink). Even though the Upload Speed Test measured 385 kbps (with QoS turned off), voice quality was NOT good until I reduced MUS to 326. For the 128 kbps uplink, I tried MUS settings of 128, 109, and 64 (using the G726-32 codec). I rebooted the Sipura (using the /admin/reboot URL) between all setting changes. For my 384 kbps uplink, I tested with sip:613@fwd.pulver.com, listening for any problems in the echo. For a relative's 128 kbps uplink, I called and listened while they simultaneously talked and ran the Uplink Speed Test on their computer. (For the 128 kbps uplink, there was a router in between the computer and the SPA-2100, with the router's Max MTU = 576. This should have fragmented all the Upload Speed Test's outgoing packets, such that serialization delay should not have caused the voice problem.)

http://tomsnetworking.com/Reviews-20...-SPA2100-4.php says "The bottom line is that it looks like the recommended TBF-based QoS did the trick of restoring near-perfect call quality with simultaneous continuous uplink data traffic." However, that article doesn't say whether MUS was set at 100% of tested uplink bandwidth, doesn't say how much uplink bandwidth they had, and says nothing about Max MTU or serialization delay.

[yaman]

i did a test witht he spa9000 wich is similar to spa2100, my upload is 100Kbps upload and usign G711 as codec and ihave set the spa2100 either cbq or tbf ad the result is i have to wait till the page has finish opening before i can continue the conversation.

advise me if you were able to get a solution for this problem


thanks

[voip247]

Originally Posted by yaman

i did a test witht he spa9000 wich is similar to spa2100, my upload is 100Kbps upload and usign G711 as codec and ihave set the spa2100 either cbq or tbf ad the result is i have to wait till the page has finish opening before i can continue the conversation.

advise me if you were able to get a solution for this problem

Nothing yet. I'm trying to get the issue escalated to Sipura/Linksys ( http://voxilla.com/index.php?name=PN...ic&p=35595 ).

[PhoneBoy]

This is what came back from Linksys:

At 128 Kbps upstream, we recommend using G.729 as the codec, QOS settings at TBF and Max Uplink Speed at 100 Kbps.

[pap2boy]

Originally Posted by yaman

i did a test witht he spa9000 wich is similar to spa2100, my upload is 100Kbps upload and usign G711 as codec and ihave set the spa2100 either cbq or tbf ad the result is i have to wait till the page has finish opening before i can continue the conversation.

For those who have SPA2100/9000 units handy, can you please open up the unit, take the Hi-Res snapshots of these devices, and post them here for others to inspect if it is possible to hack an SPA2100 into an SPA9000 to save $$$? If you can't post the snapshots here, at least you can PM to me and I will have these snapshots hosted somewhere else. Rumours have these two devices are identical with the exception SPA9000 has 2x the flash memory.

[voip247]

Originally Posted by PhoneBoy

This is what came back from Linksys:

I tested this configuration while running the upload test (above) and it worked flawlessly. In fact, I couldn't even tell from listening to the the voice that the upload test was running at all. So thanks to PhoneBoy and Sipura/Linksys!

[meirgreen]

Okay, great. But in that case...
what should the bandwidth setting be for 96 kbps upload speed?

[voip247]

Originally Posted by meirgreen

Okay, great. But in that case...
what should the bandwidth setting be for 96 kbps upload speed?

Well, if you use TBF and G.729, as Sipura/Linksys recommended, then it should work if you use a sufficiently low bandwidth setting. "Sufficiently low" might be 75 kbps (since 100/128 = 78%, and 78% of 96 kbps = 75 kbps) or 68 kbps (since 128-100=28, so 96-28=68).

So I suggest trying 75 first; if you hear any problems, try 68. But if you're not willing to use G.729 and TBF, all bets are off.

[yaman]

Originally Posted by meirgreen

Okay, great. But in that case...
what should the bandwidth setting be for 96 kbps upload speed?

i am using spa9000 which is similar to the spa2100, i noticed if i am using G711 and my upload bandwidth is 100Kbps only which seems very narrow to run another application such as even opening a webpage, if i set the QOS to none, the QOS works beautifully without a problem up to the point that while speaking on the phone and i try to open a page on the web, the page sometime does not even open or if it opens it goes very slowly and the voice conversation continues like nothing is happening.
according to sipura support, they stated that all sipura device have Diffserv type QOS.


if i set it to TBF or CBQ with 100 Kbps as upload, than the QOS will never work and the call will be disasterous with full of custs and one way voice.

i recommend that QOS to be enabled only if a high upload bandwidth is available.


thanks

[meirgreen]

I don't think DiffServ makes any difference unless your ISP supports it. The Israeli ISP, who provides 96 kpbs upload, does *not* honor customer QoS bits. Because if they did, all the smart E-mule users would start setting the bits to prioritize their bandwidth.

And, no, I can't go and test out the different speeds to see what works, because the SPA2100 in question is on someone elses property.

I already noticed that when I load the web admin page remotely, the call in progress breaks up, even with QOS set.
Why shouldn't it all work with the upload speed set correctly?
Don't they test these things before they push them out the door?

Yaman, what type of ISP/network is your spa9000 connected to that honors DiffServ?