adventures of a VoIP / SIP / IMS trainer & contractor|info@rzfeeser.com

voip

A basic Asterisk v1.8 extensions.conf configuration

This is a basic extensions.conf (the Asterisk dialplan) configuration for Asterisk v1.8. As you can see, only two lines are actually necessary in extensions.conf for the SIP user agents defined in sip.conf to be able to call one another.

If you’re confused, than examine this dialplan in conjunction with my previous blog post on configuring a basic sip.conf in Asterisk 1.8. It may also enhance your understanding of Asterisk to examine the script I posted that complies any version of Asterisk in Ubutnu.

The default location for extension.conf on an Ubuntu 10.04 and 12.04 system is:
/etc/asterisk/extensions.conf
The configuration file is commented for maximum clarity. The active code […]

By |June 19th, 2013|Blog|0 Comments
Read More

How to calculate necessary bandwidth for a VoIP network

When I teach SIP, H.248, Cisco, or Avaya training courses, I’m often asked how to calculate necessary bandwidth for a VoIP network. I’m actually headed out the door to teach a SIP Essentials class this week, and seeing as I am anticipating this question, I thought I might post some helpful resources on the subject.

Essentially, it’s a question of the type of payload (codec you’ve selected), the sample period (how many samples per packet), and then taking into consideration the IP/UDP/RTP header information (generally, 40 octets), and then transmission overhead (generally, Ethernet 18 octets). After calculating bandwidth required for one call, […]

By |January 27th, 2013|Blog|0 Comments
Read More

A basic Asterisk v1.8 sip.conf configuration

One of the many goals I set for the students attending my Session Initiation Protocol class, is to leave them with an ability to maintain their own home Asterisk SIP PBX. After all, if you don’t exercise a muscle, it will atrophy; your SIP muscle is no different. It is only by rolling up your shirt sleeves, and diving into the fray, that you can really begin fully understand SIP (and those protocols it is accompanied by… SDP, RTP, DNS, etc).

So, my hope is that this post can take some of the mystery and apprehension out of the initial […]

By |October 29th, 2012|Blog|1 Comment
Read More