I am a noob to telephony. I tried to find info with regards to using Asterisk over long distances.
Background: There is an office in the USA and in the Netherlands and I want to setup Asterisk such that all phones in the US office and Dutch office are just extensions of one another.
The US office has 2 PTSN comming in and 1 ADSL 768kbps down, 384kbps up. It will be similar in the Netherlands.
Note: The ADSL is also used for other Internet traffic (email, web, ssh, dns, etc.). Thus I would probably want/need some sort of traffic shaping. What has been others experiences with traffic shaping (using Linux) and VOIP? Any cavaets?
Would I have good sound quality and how many concurrent connections could I achieve through the ADSL with reasonable sound quality? Any recommendations?
You could have an *-box at each office. Then you could hook them up to each other with any site-to-site VPN (OpenVPN, Openswan, …).
After that you could create an IAX trunk to let calls go from server A to B and vice versa.
A nice tool to assist you in traffic shaping could be MasterShaper (shaper.netshadow.at)…
The amount of connections and quality depends on your codecs, you can limit the amount by placing limits on the trunk, so a little tweaking and trying out will give you some answers on what works best. (search voip-info.org for codecs and bandwidth, to find an overview)
What you want to do is very easy. If you set up an asterisk box in each office, and then set up an IAX trunk between the two boxes, you could 4digit dial each other quite easily, especially if you just want to go with softphones on PCs, don’t even need any special hardware.
I doubt honestly that you’d need to get into traffic shaping or QoS for your calls…unless we are talking alot of calls (say more than 10 at the same time). I’ve got similar config between the US and Australia, works perfectly fine over regular dsl.
Try Asterisk@home if you aren’t sure about setting up a server (its an easy way to test), and look in this forum for a description about connecting two asterisk boxes together with IAX trunking. (i know there are at least 200 examples that you can pick from).
I imagine that the default codec and config that you try will more than satisfy you. You can expand on it by adding in a Digium card to tie in a POTS line or PRI into either site, and be able to make outbound calls from one pbx to another and avoid overseas toll charges.
However, with respect to QoS. I currently do not implement QoS, but when I ssh to a box that is downloading an ISO image or an email with a large attachment, my ssh session slows to a crawl. I can’t imagine that it wouldn’t affect a VOIP call which is sensitive to delays of packets.
I have thought for quite some time that Virtual Private Networks were a really great tool, but that the remote user really was lacking something. That “something” was remote access to all of the features of the company telephone system.
With the advent of Asterisk, we can upgrade from Virtual Private Network (VPN) to the Virtual Private Office (VPO) and we can do it cost effectively. In fact, I would argue that a VPN has become a subset of a VPO.
I think that ‘virtual office’ solutions may become a hot product in the next few years- why bother with a whole building when you can just stuff a rack of servers somewhere, send your employees a phone and some software that allows them to do everything they can do otherwise? For larger corps it helps to have everybody in the same building, but for smaller starting biz’s that can’t afford a real office such things could be a compelling solution. I wouldn’t be surprised if we start seeign packaged virtual office type products (or at least integration services) advertised soon…
