Protocol Basics

Layer:
Application

Transport:
TCP or UDP

Port(s):
5060, 5061

RFC(s):
2543, 3261

SIP (Session Initiation Protocol)
SIP is by far the most popular protocol used in VoIP communication today. SIP was designed as a signaling protocol in charge of setting up and tearing down sessions between two or more devices. Additionally, SIP can be used to modify existing sessions. The protocol was designed [...]

Categories: Voice / Voice over IP

For about a month, I’ve had a problem with my Contacts app crashing on my T-Mobile G1. Whenever this would happen, I would be forced to close the Contacts application. This was a pretty major pain in the butt since I tend to use the Contacts and Favorites tab to do most of my dialing.
It [...]

Categories: Voice / Voice over IP

This information is contained in the documentation for the ATA, but I never have that handy when I need it. Here are the steps for performing a factory reset on a Sipura 2100 ATA:

Plug an analog phone into either phone port.
Dial ****
Dial 73738#
Dial 1#
Hangup

Categories: Voice / Voice over IP

If your PBX is Asterisk based, you need to subscribe to the asterisk-announce mailing list. This is where Asterisk developers post information regarding new releases and security updates for all versions of Asterisk. If you were on this mailing list, you would know that two recent security alerts (see below) had forced Asterisk developers to [...]

Categories: Voice / Voice over IP

I ran across an instance of Asterisk the other day that was working fine except that none of the MeetMe conference bridges were valid. The conference bridges were previously working, but the server had recently lost power and rebooted. Whenever someone tried to use a conference bridge, the following message appeared on the Asterisk console:
WARNING[29733] [...]

Categories: Voice / Voice over IP