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Required Internet Speed for Obi voip service

Started by lightspeed, March 14, 2012, 12:39:22 PM

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lightspeed

What is the minimum internet data speed (up and down) needed for the Obi/Google Voice combination to provide good voice quality without a chop?

QBZappy

#1
lightspeed,

I have one set up in Bolivia. Far end 256K up + 729 codec. Works a treat.
Owner of the 1st OBi110/100 units in service in Canada & South America. 1st OBi202 on my street. 1st OBi1032 in Montreal.

QBZappy

By the way, can anyone beat that? How low can you go?
Owner of the 1st OBi110/100 units in service in Canada & South America. 1st OBi202 on my street. 1st OBi1032 in Montreal.


QBZappy

lightspeed


Have a read here:
http://www.voip-info.org/wiki/view/Codecs

OBi has settings in the unit which can be used to optimize the call experience (call quality). Your service provider should tell you what codecs are available to you on their servers.
Owner of the 1st OBi110/100 units in service in Canada & South America. 1st OBi202 on my street. 1st OBi1032 in Montreal.


Ideasmiths

#6
Dear QBZappy

How do you get G729 codec working ?

I am using ObiOn PC at home to call an Obi110 in the office and through it's PSTN line. I configure the settings remotely via ObiTalk.

I went into Obitalk and unchecked the 'enable' box of G711U, A, and all the rest of the codec and left G729 enabled. But when using Softphone dialling through ObiOn PC, it would ring, connects and then disconnects quickly. The Call Status would show that there is no Tx/Rx as shown



This is a working call, using default Codec Profile A (with G711U)





The only lowest codec I could used was G726R32 (sounds okay)...if I try G726R24 and anything lower, same hangup issues.  

Thank you

QBZappy

Ideasmiths,

Quote from: Ideasmiths on April 27, 2012, 05:44:23 AM
I am using ObiOn PC at home to call an Obi110 in the office and through it's PSTN line.

Both sides of a voip call need to use the same codec. A call to PSTN can not use 729 unless the server can transcode the call in progress. I don't think the OBi has this ability. 711 codec is the base line codec for PSTN and Google voice.

Quote from: Ideasmiths on April 27, 2012, 05:44:23 AM

How do you get G729 codec working ?

I went into Obitalk and unchecked the 'enable' box of G711U, A, and all the rest of the codec and left G729 enabled

Another way to control the codec selection is when making a voip call you can prioritize the codecs without disabling any of them. If you look in the OBi wb page in the "Codecs" section you see a control for "Priority". You can select the order you would like to try or disable it completey by unchecking the enable box above. Althought I never use it, I think you can also prefix the dialed number so that it is forced using a specific codec.
Owner of the 1st OBi110/100 units in service in Canada & South America. 1st OBi202 on my street. 1st OBi1032 in Montreal.

Stewart

I am guessing that the softphone you are using does not support G.729.  However, why do you want to use a compression (lower quality) codec?  Are you unable to get a fast Internet connection?  Have a connection with a high usage cost or very low bandwidth cap?  Having a voice quality issue that you believe may be mitigated with a compression codec?


Ideasmiths

#9
I am just testing the various codec as I just completed the setup. I have 2xObi110, one in my home and the other in the office. My test is now using the ObiOn PC and Softphone to call the office Obi110 and use the PSTN. My assumption was that ObiON (if have G729) would connect with the Obi110 (G729) and everything should works?

Updated: You are correct, the NCH softphone I am testing do not support G729....back to the drawing board....

At this moment, I am guessing that the network in my office is congested/high latency etc because when I use the G711u, sometimes the other party complain that my voice is choppy. When I enabled only the G726R32 codec, the communication was smoother. I want to see if I can try G729 to further improve the choppiness and giving up some voice quality.

It is strange that I cannot enable G726R40 or G726R24 or G726R16 or G729. Could it be that ObiON PC software is stuck with only G711u codec? I'll try using my home Obi110 (G729) to call the office Obi110(G729)....

Thank you for your ideas

Stewart

AFAIK, the OBiON app is just a signaling protocol converter and has no ability to transcode or otherwise deal with codecs.  On an outbound call, whatever codecs are advertised by the softphone are presented to the remote OBi, which will select the first one in the softphone's list that is enabled in the OBi.

Because upstream voice quality issues are much more common than downstream, I suggest that you confirm that the trouble is really at the office end -- if it's at home, a QoS setting in your router may solve it.  Try making voice calls from home that don't involve the office, e.g. with Gmail or with your home OBi and GV or a SIP service.  Likewise, try some VoIP calls at the office that don't involve your home Internet connection.

If the office connection is the culprit and can't be fixed, a possible alternative is calling via a SIP provider that permits sending your business number as caller ID.  Of course, the calls won't be free, but depending on your usage level, they could be half a cent per minute or less.

Ideasmiths

#11
Thanks Steward....

Well, unfortunately SIP services at this moment is not a feasible solution because there is a company installed hardware/software monitoring system in the office tied to the PSTN lines. The function is to detect Do Not Call numbers and I do not have access to that system. So each call I make has to be 'safe' and pass through the system and out the PSTN line.

I managed to try a softphone that has G729 codec and it works with the Obi Settings. I also tried using my home Obi and it works 'okay' with G711U, so I guess it is the network latency between my home->ISP->Office ISP->Office network->Obi110->PSTN line.

Tried the G729 this morning and the voice quality is just as good as the G726R32 and G711U. I will try to solve the rest of the latency issues progressively.  :)

Stewart

Long latency in a voice path does not directly relate to poor quality, as long as only one party speaks at a time.  It does cause trouble in three common situations.  If one party interrupts the other, the second party will have spoken several more words before he hears the interruption, causing confusion.  This is often compounded by the poor "doubletalk" performance of most VoIP systems.  If latency is very long, when a party stops speaking for a moment, he may incorrectly conclude that the other chose not to reply and continue with his next thought.  However, if there are also (perhaps unrelated) quality issues, high latency is very frustrating, because when one party asks the other to repeat what wasn't heard, several additional words have already been spoken.

Try this test number: 1-703-376-3246.  Initially, you record a message and press #.  It's played back for you to check outbound voice quality.  Then, use option 3 for the real-time echo test, which will give you a good idea of latency.  If it's excessive, there are several ways it might be reduced.

What kind of PBX do you have at the office?  If available, a direct IP connection should greatly improve quality.  Although expensive, an off-premises extension (ISDN or analog), should get you very close to "in-office" quality.

Ideasmiths

The IT side is shielded from me, I know there is a PBX somewhere but there is no access to it. I had tried using my own 3cx IPBX before  :D. Anyway, I am located in Singapore so the echo test number won't be feasible. I just call my own mobilephone or another landline to find out how the sound is. But the real test is when I speaks to my customers and I can hear their responses.

With G711u, many of them say 'huh?...huh? during the conversation or there are long delays in their responses. I just did a speedtest today and it seem like my up link speed is only max 65Kbps and average 55 Kps. So G711u may be stuttering due to my home uplink. (my company's ISP have faster down/up speed). So I guess G729 is much better at 32Kps and the G726R32 around 55Kps was also good.

I'll give G729 a try coming monday and see how the real test go


Stewart

#14
Quote from: Ideasmiths on April 28, 2012, 06:59:03 AMI just did a speedtest today and it seem like my up link speed is only max 65Kbps and average 55 Kps.
If you have a "normal" home broadband connection (DSL, cable, or fiber), something is very wrong.  For example, even the slowest (6Mbps downstream) service from SingNet advertises 512 kbps upstream.  Conservatively, you should get 400 kbps useful (as measured by a speed test).

If you have a wired Internet connection, there could be a problem with your line, modem, or networking equipment.  Or, your line might be saturated with unwanted traffic (malware, configuration issue, filesharing in background, neighbors leeching off your unsecured Wi-Fi, etc.)  Log into your modem and look at the stats (noise margins, resyncs, retransmissions, total traffic, etc.)  Once you get that fixed, you should enjoy excellent quality with G.711 (anything over 100 kbps on a speedtest should be fine, if you refrain from surfing while on the phone).

My apology for being confused by the other (US based) posters in this thread.  For an echo test with an SG number, call +65 31581212.  This is an iNum gateway.  At the "welcome to iNum" prompt, dial 000000091#.  The actual echo test server is in Belgium, so latency will be long.  However, you can still make valid comparisons; test from your office and measure the delay.  Then, test from your softphone through the OBi and your office PBX.  The difference between those delays should be very close to the round-trip delay you'll experience when calling an SG customer on his landline. 

If you have a wireless connection (cellular data, or fixed wireless), please supply some details.  While not ideal for VoIP, it shouldn't be as bad as what you have tested.

I'm fairly close (Bangkok) and just tried speedtest.net, selecting the first Singapore server (Telin).  My DSL here is rated at 10Mbps down, 1Mbps up, and was able to saturate the line with that server.


Ideasmiths

#15
The previous speedtest result I used Kbps, so should be equivalent to the 512kbps upload speed supplied by Singnet. I changed to kbps and tested this morning, here's the result.



Looking at the codec at http://www.voip-info.org/wiki/view/Bandwidth+consumption, I was thinking that the uplink bandwidth of 512kbps or 55Kbps is a bit lower than the G711 at 87.2Kbps, hence the choppy conversation I was having.

Teracall has the table which shows how the codec's theoretical bandwidth usage expands with UDP/IP headers:

Codec BR NEB
G.711 64 Kbps 87.2 Kbps
G.729 8 Kbps 31.2 Kbps
G.723.1 6.4 Kbps 21.9 Kbps
G.723.1 5.3 Kbps 20.8 Kbps
G.726 32 Kbps 55.2 Kbps
G.726 24 Kbps 47.2 Kbps
G.728 16 Kbps 31.5 Kbps
iLBC 15 Kbps 27.7 Kbps

BR = Bit rate
NEB = Nominal Ethernet Bandwidth (one direction)

Stewart

Sorry for the confusion about measurement units.  In any case, the measured upload speed of your line is sufficient for at least five simultaneous G.711 calls, so we need to look elsewhere for the trouble.  Make a test call through your office OBi.  After at least two minutes (and while the call is still in progress), access the office OBi's web interface and display the Call Status.  You can usually do this remotely with a simple port forward, but your office firewall (or policy) may not permit that.  If you can connect to the office LAN via VPN, you may be able to access the OBi over that link.  Or, if you have remote desktop access to your office PC, run a browser there to access the OBi.  Worst case, have an associate open the page and save a screenshot.  Do this test with both your softphone and your home OBi as the calling source.

Here is a call through my OBi at a time when the Internet path was less than perfect.


Items worthy of special note:
Peer RTP Address should match the public IP of your home connection.  It's possible that because of firewall settings at one or both ends, OBiTalk had to proxy the audio, probably through a server in California.  Obviously, that's asking for trouble.

With a clean connection, Jitter Buffer Length should fall to ~90 milliseconds.  In my case, repeated underruns caused it to remain high (190 is the starting value).

Packets Lost and Packets Late are the key figures.  If you have lots Lost and few or none Late, this is probably a line error issue or similar.  The opposite likely indicates delays caused by competing traffic on one LAN or the other.

dircom

#17
Quote from: QBZappy on March 14, 2012, 02:28:35 PM
lightspeed,

I have one set up in Bolivia. Far end 256K up + 729 codec. Works a treat.

Does GV work in Bolivia ok?  ie, calls in and out to the US work fine?

I have a friend in Belize, I am going to configure an Obi 100 for them, and ship
they did a speedtest .85 Mbps down / .45 Mbps up  (850Kbps/450Kbps)
just found out, their internet is via a small microwave dish on a pole

From what I understand GV only supports G711, so G711 should work ok on their internet speed?