Vonage Sound Quality

Posts: 4 · New Forum Member Joined: Oct 22, 2003 Posts: 4

I have now been using Vonage for 4 months now - but I have never achieved satisfactory sound quality. Specifically, these are the problems I have faced:

- In domestic calls, it seems that about one third of my calls have poor quality, to the extent that the other party mentions that the connection is bad.

- In International calls, the percetage is much higher, vast majority of the calls are poor quality.

- I do a number of conference calls from home - and there is some interference with conference call systems - the sound quality is horrible, so I cannot use it for conference calls.

I have a CableVision Optima Online internet service, which has worked very very well and has always delivered excellent bandwidth. The Vonage box is a Cisco ATA 186.

I've now pretty much stopped using Vonage, and I have been considering disconnecting it. But a web site asked me to write a review of Vonage, so I thought to write a fair review I should try to find out if I am doing anything wrong. I am asking to find out if my experience is unusual, or is there something I may be doing wrong.

Thanks for your help.

Arun Gupta

Posts: 104 · Vonage Forum Senior Joined: Jan 31, 2004 Posts: 104

Vonage terminates both international and national long distance in the same manner, namely dumped to a normal PSTN ASAP -- so to some degree you may be imagining problems with international. Calls to spooky wooky countries (basically any country with a dictator) introduce an assortment of problems with any carrier as the call is often passed to numerous carriers before finally terminating.

What you are NOT imagining (no offense intended in any of these remarks BTW) is that people you are calling are hearing poor quality. My bet is you're hearing them just fine but they're saying they hear you poorly.

The problem is two fold, your upload speed may be compromised (typical if you're on a cable modem) and second the CODEC (software used to encode your voice into packets) in the MOT or Cisco box is basically crap.

Voip despite all the noise is a relative bandwidth hog. Like a passenger train - it must depart and arrive 100% on schedule for perfection to be achieved. Delays either in sending or receiving quickly result in poor voice quality.

Posts: 4 · New Forum Member Joined: Oct 22, 2003 Posts: 4

Thanks for the prompt and excellent response, ckoehncke.

I also have a regular SBC landline phone. So whenever I've had problems with Vonage, I've called back on my landline - invariable with excellent sound quality. So the quality problem is definitely not in the other country's phone system, it is definitely with my Vonage connection. The countries that I've tried with Vonage, all with sound problems, Japan, India and Italy.

For international calls, where does the dump to PSTN take place, in US or in the foreign country?

I just ran speedtest on my cable connection - download is 4 Mbps, upload is 150 Kbps. So I can see the problem with the upload. What is an acceptable upload speed for Vonage to function satisfactorily?

Thanks again.

Posts: 4 · New Forum Member Joined: Oct 22, 2003 Posts: 4

And I forgot to ask. If the CODEC in Cisco and Motorola boxes is crap, what do you recommend?

Posts: 243 · Vonage Forum Master Joined: Jan 18, 2004 Posts: 243

I think maybe 150 up is a bit low. If you use the max setting for bandwidth it uses something like 90k.

Here are my speed tests and I can say with my connection I've never had a call that sounded bad. In fact my Vonage service is so clear it sounds like the person is in the next room.

*********** Testing Results ************

Upload Speed: 508 KiloBits/sec
Download Speed: 1637 KiloBits/sec

Posts: 37 · Vonage Forum Junior Joined: Feb 12, 2004 Posts: 37

My OptimumOnline connection gives me more than 900kb/sec up, so I've never had a voice quality issue. Vonage has been indistinguishable from a regular phone line. You might try setting Vonage to use a lower bandwidth, which you can do on the web site.

You may also have other internet problems such as packet loss. There are on-line test for that too.

Posts: 10 · Posted: Sat Mar 06, 2004 8:46 am Post subject:

Try the speed test and see what results you get:

https://secure.vonage.com/vonage-subscribe/subscribe/test.do

*********** Testing Results ************

Upload Speed: 350 KiloBits/sec
Download Speed: 2288 KiloBits/sec

This connection qualifies for Vonage
hosted DigitalVoice service

===============

I've gotten excellent voice quality with these numbers.

I subscribe to Earthlink Cable on a Time-Warner Cable system.

Posts: 104 · Vonage Forum Senior Joined: Jan 31, 2004 Posts: 104

Ah ... you wish to enter the murky world of international call terminations do you Twisted Evil

?

Vonage sends your outbound calls to typically a Global Crossing gateway located in the U.S. The location of the gateway varies (I can't figure out exactly why for the moment).

Now Global Crossing (GC) has your phone call on their network and Vonage is basically done with the call. International calls operate like a "spot market" with rates changing daily if not hourly. Based upon your call destination, GC selects the cheapest partner of the day and sends your call along the way. The call may or may not continue in an IP format at that stage.

GC does monitor it's partners for quality circuits (basically looking for calls of short duration which they equate to people hanging up due to poor quality). So why is an AT&T Int'l call better. Simple -- because AT&T has a reputation to maintain AND more important does not want you calling to complain (as it cost a bunch of money for them to speak with you). Thus - AT&T closely monitors their termination partners and acts quickly to remove anyone who starts to cause trouble.

There are literally hundreds of termination companies in the world and managing these relationships is often complex and larger carriers have entire departments who do nothing more than work on these agreements. The objective being giving me the best service at the lowest price.

Now on to voice quality issues related to Voip

Many of posters have indicated they have just fine upload and download speeds as reported by a variety of speed testers. However, that's really not the problem.

The issue is two fold, latency and the CODEC.

As you speak the DSP takes your voice and chops it up into samples. Using the algo of the CODEC, the DSP (in your MOT or Cisco box) then basically does the equal to Winzip and encodes the voice sample and puts it into an IP packet. It then drops the IP packet over to the Ethernet Forwarding chip (also in your MOT/Cisco box).

The forwarder now try to send the upstream. Voip uses UDP meaning basically the forwarder dumps the voice packets into the Internet and simply hopes they reach the far end AND in the correct order

The FAR END (the gateway receiving the packets) knows that packets may actually be received out of order. Thus it has something called a 'jitter buffer'. Basically it introduce a slight delay in order to ensure it has all the packets. But what if a packet is delayed. As voice is 'real time' it can only wait so long thus after a pre-determined period of time, the FAR END has no choice but to un-ZIP the packets and turn it back into voice.

Missing packets mean missing voice samples and they result in the clipping, static or general poor voice quality you hear.

There are standards for CODEC development. But there is still an element of art in how a CODEC 'zips and 'unzips the packets. It's much improved from early Voip days but still could be improved further. As it's built into your box and the remote gateway, there is basically little you can do to improve. Time will help.

Posts: 4 · New Forum Member Joined: Oct 22, 2003 Posts: 4

Thanks again folks for your help. I ran the speedtest provided on the Vonage site, and it gave me:

"Upload Speed: 135 KiloBits/sec
Download Speed: 3100 KiloBits/sec
This connection qualifies for Vonage
hosted DigitalVoice service"

I had set my bandwidth saver sound quality to 90 kbps, I just changed it 50 kbps. Would that improve sound quality or make it worse?

I have to also now diagnose why I am only getting 135 kbps upload on my cable modem, may be my networking gear.

ckoehncke, thanks for the illuminating response on international calls. So now I can see why international calls are hit and miss.

Considering Circuit city is now going to resell Vonage, I don't know if Vonage and Voip is ready yet for the average consumer.

Posts: 104 · Vonage Forum Senior Joined: Jan 31, 2004 Posts: 104

Like wine, critics all over the map on what CODEC sounds best. Vonage currently supports 3 (G.711, G.726 and G.729). Each has decreasing bandwidth requirements. The higher bandwidth allows for more samples of your voice to be taken (and less of the CODEC trying to make up the difference).

The 'rub is that the high quality codec (G.711 for example) send much larger packets out thus if any of them are delayed or mis-routed -- voice quality suffers fast.

I've tried them all, but the MIDDLE range (like life in general) is where I've found the best compromise. This is G.726 whose bit rate is 32 kbps (vs 64 kps for G.711) and occupies a nominal 55.2 kbps when transmitting (IP overhead).