"Is it possible to installa elastix ... on your vps?" Yes.

"Will voip services work without limitations?" For the most part, yes. The only "limitations" I can envision are systemic/environmental limitations beyond DigitalOcean's control.

"The vps has public ip address or nat?" Public IP.

How much does elastix cost? You should check out snom ONE ... multiple layers of solid security protections & they offer a "free" license (limit of 5 extensions, I believe).

Elastix is free.

Thank you for your information! I'm going to try digitalocean vps :)

Just purchased, but the network speed it is so slow. :( I do not think I can use it for voip or any other realtime service :(

What do you mean by slow? Can you please open up a support ticket so we can take a look? Thanks! :]

I confirm it is definitevely slow. I will open a ticket to see if something is wrong.

Just as reference:

[root@centralino ~]# wget "http://downloads.sourceforge.net/project/elastix/Elastix%20PBX%20Appliance%20Software/2.4.0/Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso?r=http%3A%2F%2Fsourceforge.net%2Fprojects%2Felastix%2Ffiles%2FElastix%2520PBX%2520Appliance%2520Software%2F2.4.0%2F&ts=1377188051&use_mirror=kent"
--2013-08-22 16:15:31-- http://downloads.sourceforge.net/project/elastix/Elastix%20PBX%20Appliance%20Software/2.4.0/Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso?r=http%3A%2F%2Fsourceforge.net%2Fprojects%2Felastix%2Ffiles%2FElastix%2520PBX%2520Appliance%2520Software%2F2.4.0%2F&ts=1377188051&use_mirror=kent
Resolving downloads.sourceforge.net... 216.34.181.59
Connecting to downloads.sourceforge.net|216.34.181.59|:80... connected.
HTTP request sent, awaiting response... 302 Found
Location: http://kent.dl.sourceforge.net/project/elastix/Elastix%20PBX%20Appliance%20Software/2.4.0/Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso [following]
--2013-08-22 16:15:31-- http://kent.dl.sourceforge.net/project/elastix/Elastix%20PBX%20Appliance%20Software/2.4.0/Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso
Resolving kent.dl.sourceforge.net... 212.219.56.185
Connecting to kent.dl.sourceforge.net|212.219.56.185|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 687478784 (656M) [application/octet-stream]
Saving to: `Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso'

11% [=================> ] 75,815,549 --.-K/s in 46m 51s

2013-08-22 17:02:23 (26.3 KB/s) - Read error at byte 75815549/687478784 (Connection timed out). Retrying.

--2013-08-22 17:02:24-- (try: 2) http://kent.dl.sourceforge.net/project/elastix/Elastix%20PBX%20Appliance%20Software/2.4.0/Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso
Connecting to kent.dl.sourceforge.net|212.219.56.185|:80... connected.
HTTP request sent, awaiting response... 206 Partial Content
Length: 687478784 (656M), 611663235 (583M) remaining [application/octet-stream]
Saving to: `Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso'

24% [++++++++++++++++++======================> ] 169,714,426 218K/s in 25m 31s

2013-08-22 17:27:55 (59.9 KB/s) - Read error at byte 169714426/687478784 (Connection reset by peer). Retrying.

--2013-08-22 17:27:57-- (try: 3) http://kent.dl.sourceforge.net/project/elastix/Elastix%20PBX%20Appliance%20Software/2.4.0/Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso
Connecting to kent.dl.sourceforge.net|212.219.56.185|:80... connected.
HTTP request sent, awaiting response... 206 Partial Content
Length: 687478784 (656M), 517764358 (494M) remaining [application/octet-stream]
Saving to: `Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso'

25% [+++++++++++++++++++++++++++++++++++++++++ ] 172,822,934 524B/s in 12m 49s

2013-08-22 17:40:54 (3.95 KB/s) - Connection closed at byte 172822934. Retrying.

--2013-08-22 17:40:57-- (try: 4) http://kent.dl.sourceforge.net/project/elastix/Elastix%20PBX%20Appliance%20Software/2.4.0/Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso
Connecting to kent.dl.sourceforge.net|212.219.56.185|:80... connected.
HTTP request sent, awaiting response... 206 Partial Content
Length: 687478784 (656M), 514655850 (491M) remaining [application/octet-stream]
Saving to: `Elastix-2.4.0-Stable-x86_64-bin-04feb2013.iso'

82% [+++++++++++++++++++++++++++++++++++++++++===============================================================================================> ] 566,197,850 2.75K/s eta 13m 57s

So many errors and hours to download one ISO. Please consider that the host is sourceforge.
In the meantime, the ssh connection was lagged, sometimes I've to wait several seconds just for typing in.

I'm no expert, but that sounds like abnormal behavior.

What kind of latency are you experiencing?

If you scroll down to the bottom of the FAQs page, you'll find links to run some speed tests.

What's the output of this command?

curl -s https://kmlnsr.me/speedtest.sh | bash

Anyone successful on installing elastix on Digitalocean yet?

Im also eager to know how to install elastix in digital ocean, if someone successfully did it... please please please let us know, i'll subscribe to this thread...

I'm working on it rigth now following this old setup guide in a droplet Centos 5.8 (32b)

[http://elastix.org/dokuwiki/doku.php?id=how-to_install_elastix_from_centos5]

I'll kepp you guys posted if this goes trough! XD

So far so good...