HowTo: 6 Steps To Tune Your Voice Quality
 

For those of you interested in performance tuning your audio please check out this new tutorial:

HowTo: 6 Steps To Optimize Your Audio

Please post any comments / questions in this thread.

Thanks.

Number 7
 

Step Number 7 and it should be No. 1 is the ping Command , like me in Jerusalem see the Following tests ::::

ping average to au.voxalot.com is 587ms


ping average to us.voxalot.com is 214ms


ping average to eu.voxalot.com is 130ms

So the Best One is the European Server :cool:

Hi, martin

What is the exact meaning of "Symmetric NAT Handling" field on the Member Details page?

if this field is yes, does Voxalot act as both STUN server and OUTBOUND proxy server? or only act as OUTBOUND proxy server?

I find that if i set this field to "no", i can not call "*600" successfully though i have set a STUN server(x-ten STUN server) in my ATA(my ATA is behind NAT).My router is Netgear WGR614(v6),it should not be symmetric NAT.

Thanks.

The Voxalot servers have built in logic that can detect whether or not they need to alter the client messages and/or proxy the voice stream.

When you set "Symmetric NAT Handling" to "No" it basically tells Voxalot to disable this logic.

If you have "Symmetric NAT Handling" set to "No" and *600 does not work, then something is not quite right on your client.
.

Just now, i have confirmed my NAT(Netgear wgr614v6) is cone NAT type, not symmetric NAT type. My ATA SPA-3102 is behind the NAT.

After that, I set "Symmetric NAT Handling" field to "yes" on the Member Details page , and i disabled stun server and kept outbound proxy blank in my ATA. I find that i can make call via Voxalot successfully.

My understanding is:

1.Whether your ATA is behind cone NAT type or symmetric NAT type,if i you set "Symmetric NAT Handling" field to "yes" ,Voxalot will act as OUTBOUND proxy server even that you have disabled stun server and kept outbound proxy blank in your ATA.

2.if i you set "Symmetric NAT Handling" field to "no" , only when your ATA has a public IP address or your ATA is behind cone NAT , can you have chance to optimize your voice route. If your ATA is behind symmetric NAT,you have not any way to optimize your voice route ,even that you can not make any call via Voxalot.

Are these correct?

Thanks.

1. Yes, however even with "Symmetric NAT Handling" field to "yes" Voxalot will attempt to optimize the voice route however if it can not, it will fall back to proxying the voice.

2. Yes and No. Setting "Symmetric NAT Handling" field to "no" disables the logic I outlined above. Once disabled, the only way you will get 2-way voice is if external IP addresses are passed to Voxalot by the client either directly or indirectly by using something like STUN on the client.
.

Setting "Symmetric NAT Handling" to "No" causes a dead line when I try to establish a call.

Setting "Optimize Audio Path" to "Yes" causes the audio to skip, and so the audio drops after a few seconds.

My situation: Siemens C45 (DECT handset) > Siemens C450IP (DECT VoIP gateway) > Linksys WRT54G v2.2 w/ Tomato firmware > Motorola SBV5120E cable modem

You may check your NAT type at first if you set "Symmetric NAT Handling" to "No".

You can download a software tool "winstun" to check your NAT type.
here:SourceForge.net: Files

Thanks. I got this message:

I have set "Symmetric NAT Handling" to "No" now, and have set-up STUN in my VoIP device.
Could anyone explain to me what the difference is between "Symmetric NAT Handling" and "STUN"?

Hi Martin, Could you please explain a little bit the difference between using STUN or using the Voxalot "Symmetric NAT Handling" for NAT traversal, the pros and cons, and when is it more appropriate to use one method versus the other?

Thanks

Hi,martin

It will be better to rename "Symmetric NAT Handling" to "Voxalot NAT Handling" on the Member Details page.

"Symmetric NAT Handling" these words can not reflect true logic that Voxalot servers do ,and it has confused us.

Thanks.

my understanding about "Symmetric NAT Handling" field
 

My understanding about “Symmetric NAT Handling" field on the Member Details page again.

1.If you set “Symmetric NAT Handling" to “yes”, it enables Voxalot NAT handling built-in logic.

In this case, Voxalot servers can help you to solve all traversing NAT issues. You need not consider how to configure stun server or outbound proxy server(TURN) option in your ATA if your ATA is behind NAT(router).

1A. If your ATA is sitting on public IP address

Voxalot special SIP proxy server can detect your ATA is sitting on public IP address ,so Voxalot attempt to to optimize the voice route(initiate the RE_INVITEs).If your VSP supports RE_INVITEs, you will get optimization voice route(path),point to point, bypassing Voxalot RTP proxy server . If your VSP does not support RE_INVITEs, you will get triangle round-trip voice path.i.e,your ATA sends RTP voice packets direct to your VSP, the RTP voice packets from your VSP come in via Voxalot RTP proxy server.

1B. If your ATA is behind cone NAT(includes Full cone, Restricted cone, Port restricted cone)

Voxalot special SIP proxy server can detect your ATA is behind NAT, and modify your SIP(SDP) to help your RTP voice packets to traverse your cone NAT, but your all RTP voice packets should pass Voxalot RTP proxy server(RTP relay) , you have no chance to bypass it. So, hardly can you optimize voice path to p2p.

Edit: The only exception is that you have configured right stun server in your ATA though you need not do it, and you will get optimization voice path similar with "1A".

1C. If your ATA is behind symmetric NAT

Voxalot special SIP proxy server can detect your ATA is behind NAT, and modify your SIP(SDP) to help your RTP voice packets to traverse symmetric NAT, but your all RTP voice packets should pass Voxalot RTP proxy server(RTP relay) , you have no chance to bypass it. So, you have no way to optimize voice path to p2p.

In this case, you need not consider “Optimize audio path” is “yes” or “no” on the Voice Service Provider page. Regardless you set it “yes” or “no”, voice path has the same effect.


2. If you set “Symmetric NAT Handling" to “no”, it disables Voxalot NAT handling built-in logic.

In this case, you should solve traversing NAT issue by yourself . You need configure stun server or outbound proxy server(TURN) option in your ATA if your ATA is behind NAT(router)

2A. If your ATA is sitting on public IP address

a.If “Optimize audio path” is “yes” on the Voice Service Provider page.
Voxalot attempt to optimize the voice route(initiate the RE_INVITEs).If your VSP supports RE_INVITEs, you will get optimization voice route(path),point to point, bypassing Voxalot RTP proxy server . If your VSP does not support RE_INVITEs, you will get triangle round-trip voice path.i.e,your ATA sends RTP voice packets direct to your VSP, the RTP voice packets from your VSP come in via Voxalot RTP proxy server.

b.If “Optimize audio path” is “no” on the Voice Service Provider page.

Your all RTP voice packets should pass Voxalot RTP proxy server, you lose the chance to bypass it, so, you have no way to optimize voice path to p2p.

2B. If your ATA is behind cone NAT(includes Full cone, Restricted cone, Port restricted cone)
At first, you should configure stun server option in your ATA(e.g. stun.xten.com) to traverse NAT by yourself.

a. If “Optimize audio path” is “yes” on the Voice Service Provider page.

Voxalot attempt to optimize the voice route(initiate the RE_INVITEs).If your VSP supports RE_INVITEs, you will get optimization voice route(path),point to point, bypassing Voxalot RTP proxy server . If your VSP does not support RE_INVITEs, you will get triangle round-trip voice path.i.e,your ATA sends RTP voice packets direct to your VSP, the RTP voice packets from your VSP come in via Voxalot RTP proxy server.

b. If “Optimize audio path” is “no” on the Voice Service Provider page.

your all RTP voice packets should pass Voxalot RTP proxy server, you lose the chance to bypass it, so, you have no way to optimize voice path to p2p.

2C. If your ATA is behind symmetric NAT
At first , you should configure outbound proxy server(TURN) option in your ATA to traverse symmetric NAT. your sip signalling and RTP voice packets will pass this outbound proxy server(TURN) then to Voxalot servers.

These below a and b are my estimation.

a. If “Optimize audio path” is “yes” on the Voice Service Provider page

Voxalot attempt to optimize the voice route(initiate the RE_INVITEs to this outbound proxt server(TURN) and your VSP).then……….
Please help me to finish here…

b. If “Optimize audio path” is “no” on the Voice Service Provider page

your all RTP voice packets should pass outbound proxy server(TURN) and Voxalot RTP proxy server, you have no chance to bypass its, so, you have no way to optimize voice path to p2p. Unfortunately, your RTP voice packets must pass two proxy servers.

I think if your ATA is behind symmetric NAT, the best way is to set “Symmetric NAT Handling" to “yes” to avoid such troubles.




I have studied some from post written by member v164.

Welcome anyone to correct this post above.

Just saw this. Nice work!
.

NAT Setting NO and Audio Optimisation YES
 

Martin/ Hust,
Can you please explain what happens in the 2C ie. when systematic NAT setting is set to "NO" and Audio optimisation in VSP is set to "YES".

Thanks,
Nagu