Solving problems with external SIP without losing your mind

External SIP or in other words SIP through firewalls and routers or more accurately SIP traversal through Network Address Translation (NAT) is arguably one of if not the most common problem people face.  SIP is notorious for this.  This little article is my attempt to provide a simple no nonsense method of finding and fixing these problems.  Ideally before they ever happen.  To keep it simple I will assume everything on the PBX itself is configured correctly. 


FreePBX, Asterisk and Linux Advanced Topics


Here are a few advanced topics covering some things that can be done to any FreePBX or strictly Asterisk distribution.  These would be things one might be interested in doing beyond the standard Linux-Asterisk-Freepbx installation.

Aastra XML scripts part II, auto-provisioning and auto setup with RPMS

In previous posts I showed how to auto-provision and configure Aastra phones by manually installing XML scripts.  Aastra has released RPM packages for Trixbox that combines everything and adds new features as well as mDNS so the phones can find the TFTP server even if you don't have a DHCP server capable of assigning it.  The script won't install unless mDNS is installed. 


The most common SNAFUs when planning and implementing an open source VoIP PBX rollout and how to avoid them

This is a general overview of some of the more common mile high mistakes people make when doing an open source VoIP PBX project.  I won't be going into details about hardware dimensioning or software configuration.  I will just be providing a general overview of some of the system level common sense mistakes people make in terms of a typical consultant/client type of project.


FreePBX-Asterisk VoIP PBX phone system long term case study


The following is an update to a case study of a VoIP PBX phone system I installed back in October 2006 using this guide.  I feel it is time for an update to see how things have worked out long term.

Autoprovisioning Aastra phones with video demonstration

Setting up your Asterisk PBX for XML auto provisioning has 2 primary advantages.  It allows non-technical people to install phones and speeds up the process of adding a large number of phones.

XML auto provisioning is installed as follows. This assumes you already have the other XML scripts installed on the server end as discussed previously.


Aastra XML, unleash the power of Asterisk and Aastra phones (includes video)

So you got a brand spanking new Aastra 5xi phone that you want to connect to your Asterisk PBX. Implementing XML on your phones opens up a whole world of possibilities. I'll show you how to do it.

These have all been tested on my Aastra 57i phone. It should work on the 55i as well. I am not sure what will work on other phones. Some things will and some things won't.