RTP pass-through mode in Asterisk

What is RTP pass-through mode in Asterisk? The speech for VoIP calls uses RTP (Real Time Protocol) to get from one end to the other and it is compressed using one of the many speech compression codecs available. Commonly used codecs include G.711 and G.729. When you call someone through an Asterisk PBX, there will be … Read more…

High Availability and Failover options for SIP and Asterisk

Overview What’s the disaster we are trying to avoid? The assumed scenario is this: Some kind of centralised VoIP service is being offered to a number of users; the service operates on servers located at a data centre or office and the users each have a SIP client device, such as an IP phone, that … Read more…

Configuring IP phones as Asterisk PBX extensions

A first look at the SIP.CONF file It is assumed here that your IP phones all use the SIP protocol to register, make and receive calls. Before an IP phone can connect to Asterisk and operate as an extension, it is necessary to configure user account details on the Asterisk server. The configuration file of … Read more…

About IP Packet Communications – TCP and UDP

Devices communicate data to other devices on the Internet using certain recognised protocols that involve routing and transmission of packets of data to a remote device identified by an IP addresses. The most widely used protocols on the Internet are TCP and UDP. The differences between these two protocols are of a highly technical nature … Read more…