We have been using Asterisk in-house now for some months with a view to (a) providing ourselves with a professional phone system and (b) with a view to reselling VoIP services.

This has been quite a steep learning curve on several fronts but I think now after 6-9 months of using VoIP in-house we have now sorted out most of the pitfalls with Asterisk and VoIP in general.

Our first learning curve is getting used to using Linux. We have had it in the office before with a view to building low cost NAS servers based upon a rack mount chassis but we have now got to grips with using it as the platform for Asterisk. We are currently using Fedora although John has actually been off and had training on SUSE Enterprise. We now have a stable Asterisk server/PBX based upon a Fujitsu Siemens Econel 100 server. This has plenty of space for call recording and runs very sweetly. The only downside is that we now know that the Econel 100 SATA RAID drivers are only written for Redhat and SuSE Enterprise and do NOT work with other versions of Linux at all. Still the software RAID works well.

The second learning curve has been working with ITSPs – Internet Telephony Service Providers. We have yet to find the perfect partner but Telappliant and AQL are proving to be reliable. We have tried both SIP trunks and IAX and have now settled on IAX as being more reliable. We have also played with various CODECS and now use GSM. This gives the best compromise between bandwidth and quality. When you call us you will find that the quality of the speech (and on-hold music) is excellant, better than ordinary analogue is most cases.

We now have an Asterisk in-house telephone system that provides the following:

* Call transfer, hold, conference, CLI, etc.
* Out of Office anouncements according to the time and/or day or the week
* Voicemail and voicemail to email
* Easy call diversion to other numbers (mobiles for example)
* Interactive voice menus (IVM)
* Music or messages on hold
*Automatic fallback to an analogue phone line in the event of the internet failing
* Full digital call recording of all calls – internal and external
* Very cheap loca, national and internation calls – from 0.9pence per minute

The features of the system are legion and the benefits it brings are many. For example myself and John have fulltime VPNs to our houses and hardware IP phones at home. The office can now transfer calls to us at home, across the internet, and callers need not know we are many miles away fomr the office. There is no reason why you could not have operators in another country if you have a decent VPN in place.

We now feel confident enough with our systems and our ITSPs to start rolling this out to selected clients.

Target clients will be those how might typically only have up to 10 simultaneous calls, currently rent multiple analogue or ISDN lines and have home workers or branch offices. Also for some the digital call recording will be very important and enough alone to justify the system.

In the near future we will create a hosed Asterisk system so we can provide better services to the micro users who currently just have a basic SIP account.

We are also working as a matter of urgency in creating a unified messaging system that will link Asterisk and our Microsoft Exchange 2008 server. The main stumbling block here is that one system uses UDP protocols and the other IP protocols but we beleive that this is surmountable.

Keep you posted on progress.

by hostadmin on Nov 29, 2007 at 11:14 PM


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