My VoIP experience on LTE

dovij: If you're getting better results with the A580IP base than the A510IP base, then:
1. Try update the firmware on the A510IP; the 2nd last Chagall firmware release sucked. The latest is fine.
2. Try disable the Gigaset.net account and ensure that your NTP server is set to a local server, e.g. ntp.switchtel.co.za; sometimes the Gigaset bases throw a wobbly when, after repeated attempts, they fail to access these servers. DNS lookup failures on either server or non-response by the Gigaset.net server adversely affects the Gigaset base.

Hopefully once the above two points are addressed, your A510IP base should work just as solidly as the older A580IP base.

edit: Also: if you've got the Gigaset content feature (e.g. weather reports) enabled, disable it. Again, it's just another foreign server that the base sometimes fails to connect to and winds itself up retrying. Also meant to add that you don't need to be a Switch Telecom subscriber to use ntp.switchtel.co.za as your time server and the above suggestions should help irrespective of which provider you use. If you don't want to use ntp.switchtel.co.za, try za.pool.ntp.org, but keep in mind that the DNS lookup may be international, even if the server is local.
 
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gmza said:
At home I've got a Yealink SIP-T28P and a Snom M3 on extensions on a Switch Telecom Hosted Switchboard as well as a Gigaset base with two handsets (A58H and C47H) on a Switch Telecom VoIP Line service. I intermittently switch between HSPA+ (via outdoor LPDA antenna) and ADSL connections.

On the HSPA+ connection, I'm using Telkom Mobile (8.74Mb/s download; 2.37Mb/s upload, 24ms ping).
On the 4Mb/s ADSL connection I'm using Afrihost (2.37Mb/s download; 0.44Mb/s upload)

The VoIP call quality (with the Yealink and Gigasets) is excellent on both connections (using the Yealink or Gigaset handsets) and one cannot tell, from speaking on the phone, whether connected via ADSL or HSPA+. The Snom M3 is lousy and I should have smashed it to pieces long ago, but that's irrelevant.

Based on what others have posted, it is clear that LTE is more stable and consistent than 3G, however, one should also note that 3G can vary hugely based on the capabilities of the modem/router. My modem is capable of HSPA+ (21Mb/s download, 5.76Mb/s upload) and, coupled with an outdoor LPDA antenna, the results are more than sufficient to provide a stable connection for VoIP. I will, in due course, replace the modem with an LTE-capable one.

Also worth pointing out here is that, while the Switch Telecom VoIP Line service is fine for testing audio, the frequent use of the Hosted Switchboard extensions also confirms that features like presence, call transfers, etc. all work flawlessly over the HSPA+ connection.

My connection is pretty stable, but I've also tested on borderline connections. The Yealink phones (whether desktop or cordless) are MUCH BETTER at dealing with jitter and I would strongly recommend paying extra for a Yealink W52P instead of a Gigaset if one is going to be using an HSPA+/LTE connection. When your signal is good, it will make no difference. But on that one day when the signal is, for whatever reason, lousy, the Yealink audio quality will be far superior. The same sentiment has been echoed by many of our resellers operating 802.11 wireless networks. Simply put, while the hardware is of comparable quality, the Yealink firmware is far superior to Gigaset's Chagall.

Caveat 1: I am affiliated with Switch Telecom; the intent of this post was not a sales pitch, but merely to draw comparison's between Wirelesswarrior's VoIP over LTE experience and my VoIP over 3G experience.

Caveat 2: I do NOT endorse nor encourage the general use of of GSM to carry VoIP. The success of the experiences related here are heavily influenced by the fact that the GSM installations were done extremely methodically. Reading Wirelesswarrior's original thread, it's shows that multiple GSM providers were tested and an LPDA antenna used. Similarly, I also tested all four GSM providers at my location and use an LPDA antenna. Even if you get seemingly good SpeedTest results without an external antenna, the LPDA does something very important for VoIP quality: it causes much more consistent latency and connection quality, dramatically reducing jitter. That may not make much difference on good days, but it makes all the difference on bad days.
Click to expand...

I love Snoms, I have a few M9's lurking around and the odd 300's
 
Thanks gmza, very valuable posts those. Pity I'm too late on the Gigaset A510IP. Until now I had no recommendations for a Yealink.

Glad to hear my LPDA's are going to be of even more use. I've got plans underway for a dual LTE install but running on MTN. I'm picking up an XPOL cross-polarised antenna this time so that my mast doesn't look like a pine tree with four LPDA's. LOL
 
Koosi said:
Just so that you know, I had the same problem with lightning.. lost a lot of stuff.
I designed a protection system which has now finally kept the lightning out of the house.
This was put to the test recently when a tree nearby was hit by lightning. No losses, apart from the tree that burnt to the ground.
Click to expand...

Care to share your secret?!
 
Guys, especially @gmza, some urgent advice. My Siemens A510IP duo has been delivered. Unopened I could return it for a Yealink.

Question: the Siemens cost R1482; should I trade up to a Yealink W52P duo for R2622? Or should I just settle for the Siemens...
 
gmza's reply which somehow didn't post here, yet too valuable not to have in this thread:

gmza said:
As per my post, the call quality is identical when 3G signal is good. When latency and jitter are outside of normal bounds (e.g. latency > 120ms, jitter >80ms), then the Yealink audio quality will degrade less then the Gigaset as ithas a better jitter buffer implementation.

From what you described in the post, you're getting excellent latency (under ~30ms) and very little jitter. In such conditions there will be absolutely no difference in audio quality. If your results are consistent, it will make no difference. If, however, you've just posted your best results and you sometimes experience high latency and jitter (latency > 120ms or jitter >80ms), you should consider swapping.

To put this in perspective, I personally use Gigaset handsets at home over
HSPA+ for my home line and am more than happy.
Click to expand...
 
So that said, I've just setup and registered my handsets. It was stunningly simple. The Siemens A510IP has a setup wizard and even though I didn't have an auto conf code at hand, auto configuration definitely did happen. My 011 number was already captured, as were my username and password.

I did one quick test call to my cell and it was just like using my Telkom landline. :)

Tomorrow the Telkom landline gets decommissioned, so to speak, and I begin my 1 month trial - both call quality and cost - of VoIP over Telkom Mobile LTE.

Shweeeet.
 
Those Siemens handsets are the ****
I have 4 sip providers loaded on mine , one for Joburg (011), one FNB VoIP (087), 1 US, and 1 UK

Give a different number to people in different countries.
Wish I could use more than 1 for outgoing though
 
Wirelesswarrior said:
Mind explaining a bit more why you use FNB VoIP?
Click to expand...

I have 2 numbers on FNB connect, the first one is free and the 2nd cost me R50 once off with no monthlies. Calls between the 2 are free.

I have my VoIP setup at home, so one of the fnb accounts are setup there on the Siemens , AND the other fnb one is setup on my laptop/tablet/smartphone.

I travel overseas a lot, so can call my wife for free from wherever I am if I have an internet connection. So she doesn't have to do anything except pick up the phone, and its a free call. Or if I have no internet I can call her on the 087 number.

I don't have a landline at home, and use a 3g router on cell c with a 12dbi gsm antenna attached. Works perfectly, much more convenient than skype, and has cost me R50 only.
 
Thanks for the info. What about day-to-day calls using VoIP? Friends and family etc?
 
Report back - Day 1:

This looks like it's going to be just like a Telkom line. No drifting during calls, no cut outs, etc. And wow the calls connect quickly. Like instantly.

I've got the Telkom line connected to the base station as well but our friends and family know to call on the new 011 568 number. And of course all outbound calls will be made via VoIP.

Edit: I made a 5 minute call to the Middle East and the call quality was perfect. No lag or cut outs. Ditto on the other side. A 5m09s call cost R7.21.
 
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Report back - Day 3:

We've made a total of 34 outbound calls with a duration of 1h17m and received 12 inbound calls with a duration of 20m32s.

There's not one complaint so far. Yesterday there was a local number that wouldn't connect (Dischem; tried twice) but as soon as we tried another branch, it connected instantly.

Call quality remains superb with no complaints on the other side of the line. My alarm triggered yesterday and of course my alarm company couldn't get hold of me because I haven't given them my 011 568 number. Until yesterday I had the Telkom line plugged in as well but I've completely overhauled my LTE installation; the base station is now in a totally different room to the Telkom jack.

Related to the above, I've decommissioned my LPDA antennas and moved over to an XPOL-0002 cross polarised antenna. I lost 7dB on my signal (-73dB to -80dB) but this hasn't affected my LTE speeds nor my VoIP service quality.

For the record, I'm using the G.729a codec, which has the following profile: Good quality, low bandwidth use (recommended) - voice rate @ 8kb/s - IP rate @ 24kb/s - ADSL rate @ 42.4kb/s.

So far Switch is rocking. :D
 
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Report back - Day 5:

I've started to encounter resistance from the family minions as their calls to me are no longer free. While that is a valid compliant, I've tried to explain that this is for my benefit primarily due to the lightning surge history. It remains to be seen from a cost point of view.

A point on call quality, I've begun to notice that incoming calls are somewhat muffled. They just don't have that sharpness of a Telkom call - and that's not saying much as Telkom calls are very hit and miss these days, what with line noise etc.
 
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Wirelesswarrior: g.729a is a compressed audio codec. If you want 100% land-line call quality, you have to change to G.711 A-law (i.e. fully uncompressed audio). But it will consume 80kbit/s versus 24kbit/s and, if you're paying for data per GIG, then that's 874 minutes per GIG for G.711 A-law versus 2912 minutes per GIG for G.729a.
 
Report back - Day 18:

It's business as usual. There is no perceivable difference between VoIP with Switch and using a fixed Telkom line. I'm still using compressed audio and think the uncompressed audio unnecessary. I may still try it some day.

In 18 days we've made 131 calls with a duration of 6h37m19s, at a cost of R126.61. Of those calls, 60% were "National Peak" and 31% were "National Off-peak".

We've also received 49 calls with a duration of 1h28m54s.

On the hardware front, the Siemens A510IP are wonderful. They're simple and solid. Every now and then I'll fiddle with the settings to see if I missed anything. The Live Ticker (weather service) worked initially but then I turned it off as suggested my gmza. Now if I turn it on it's as if the service has been deactivated on the server. Battery life so far is great as is range. I've not used the handsets outside as yet but may do so for our Old Years Eve braai.

To sum up, everything is looking good for a full conversion to VoIP and deactivation of my fixed Telkom line. My estimated daily usage cost is R7.38 which means that in a 31 day month, my total cost could end up being R229. Add the R49.00 Switch line rental fee and the final cost would be R278. This would translate to a monthly saving of approximately R82 over Telkom. Not much at the end of the day but the bonus is that I would no longer have a live wire coming into my property (reference to the annual lightning surges that fry all).

Edit: I had a default credit limit of R1,500 on my account. With one email this was revised down to R500.00 without any questions.
 
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Azimuth said:
The case for the SIP

Some colleagues have directed me to free SIP services. The same guys that use torrents no doubt. :p Nope, I will pay for a premium service and enjoy the benefits provided.

I've basically settled on two SIP account providers:

@lantic

R25pm line rental
087 number only
Month-to-month contract
R50.00 setup fee

Switch Telecom

R49pm
011 and 087 numbers
Month-to-month contract
No setup fee

Now I didn't know about Geographic Number Portability. Switch will port (R150.00 fee) my 6-year old Telkom number which is a huge plus. I'd obviously trial the VoIP service and after a month convert from an 087 number to my old Telkom number. During this time I'll unplug my Telkom line and deactivate the call plan to run it as a "lean" parallel service (fallback insurance)
Click to expand...

Have you reviewed www.euphoria.co.za they have launched an incubator pbx for startups with zero cost per month for up to 3 extensions.
 
That is a good reference for those in the market for PBX...I'm just running a 2-person household and already committed - and super happy - with Switch Telecom.
 
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