Asterisk – Page 2

strftime Asterisk func

January 26, 2021 by eduguru

strftime Asterisk func STRFTIME Formats the datetime Synopsis STRFTIME([<epoch>][,[<timezone>][,<format>]]) Description Formats the time specified by <epoch>, localized to <timezone>. The format comes directly from the underlying C function strftime(3). If <epoch> is not specified, defaults to the current time. <timezone> likewise defaults to the timezone on the host computer. A list of possible timezones may be obtained from the directory listing … Read more

SDP – Session Description Protocol

June 14, 2020 by eduguru

SDP-example-describing-Scalable-Video-Coding-content

SDP – Session Description Protocol What means SDP? Session Description Protocol, a communication protocol for describing multimedia sessions Single-dealer platform, software used in financial trading. Sockets Direct Protocol, a low-level remote-computing protocol. Software Defined Perimeter, also called “Black Cloud”, an approach to computer security. It is used to describe multimedia sessions in a format understood by … Read more

SIP Headers – Compact Form

June 14, 2020 by eduguru

SIP Headers – Compact Form Many common SIP header fields have a compact form where the header field name is denoted by a single lower case character. Some examples are given below − Header Compact Form To T Via V Call-ID I Contact M From F Subject S Content-Length I Here is the list of … Read more

G.729 codec

June 7, 2020 by eduguru

G.729 codec G.729 is a codec with low bandwidth requirements; it provides good audio quality. The codec encodes audio in frames of 10 ms long. Given a sampling frequency of 8 kHz, a 10 ms frame contains 80 audio samples. The codec algorithm encodes each frame into 10 bytes, so the resulting bitrate is 8 … Read more

G.711 Codec

June 6, 2020 by eduguru

G.711 Codec G.711 is a codec that was introduced by ITU in 1972 for use in digital telephony. The codec has two variants: A-Law is being used in Europe and in international telephone links, uLaw is used in the U.S.A. and Japan. G.711 uses a logarithmic compression. It squeezes each 16-bit sample to 8 bits, thus it achieves a … Read more

Basic Call Flow – SIP

June 5, 2020 by eduguru

Basic Call Flow – SIP Key terms used in SIP: It is important to familiarize with these terms in order to understand basic SIP call flow. Here are few of them: Call flow: It’s a flow diagram of SIP messages — shows an ideal way how a media session carried over two endpoints. Its a … Read more

SIP : Session Initiation Protocol

June 5, 2020 by eduguru

SIP : Session Initiation Protocol Session Initiation Protocol (SIP) is one of the most common protocols used in VoIP technology. It is an application layer protocol that works in conjunction with other application layer protocols to control multimedia communication sessions over the Internet. SIP Endpoint Communication What is VoIP Technology Before moving further, let us … Read more

SIP – Headers

June 5, 2020 by eduguru

SIP – Headers A header is a component of a SIP message that conveys information about the message. It is structured as a sequence of header fields. SIP header fields in most cases follow the same rules as HTTP header fields. Header fields are defined as Header: field, where Header is used to represent the header … Read more

asterisk – cdr_mysql.conf

May 29, 2020 by eduguru

asterisk – cdr_mysql.conf ; ; Note – if the database server is hosted on the same machine as the ; asterisk server, you can achieve a local Unix socket connection by ; setting hostname=localhost ; ; port and sock are both optional parameters. If hostname is specified ; and is not “localhost” (you can use … Read more