When researching options for upgrading your telephony network or installing one from scratch, you may have come across FreeSWITCH. This is a freely available open-source application server for real-time voice communications of various types, including voice over IP (VoIP). In this article we examine FreeSWITCH to help you determine if it is right for you, and how it compares with Asterisk.

If you have been involved with telephony within the last decade, you will have heard of Asterisk as an open-source alternative to proprietary traditional and IP PBXs. If you’re considering Asterisk as a solution for your business, this article may be useful, as it will clarify what Asterisk is, how it can be implemented, and what kind of support you will need to ensure its viability as a solution.

Demystifying codecs, part 2

Different VoIP codecs digitize sound differently. Knowing which codec to use for a given application will allow you to better optimize your telephony implementations.

In this article, we examine the most commonly used codecs for VoIP, including the the G.711, G.729, G.722, G.726, iLBC and Opus codecs, and identify the situations for which each one is best suited.

Understanding how codecs work

One of the most abstract attributes of Voice over IP (VoIP) is the codec. We may wonder which codec to use in a given situation. Of course, there are general industry guidelines that help us make such decisions, but it can be unnerving to blindly follow recommendations without knowing why. For example, why should G.729 be preferred over the G.711 codec for WAN links? Why should I use G.722 when I don’t have an issue with bandwidth? What are the advantages of iLBC and Opus over the G series of codecs and when should I use them?