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H323Plus
The H323Plus project, formerly OpenH323, has as goal developing a full featured, open source ( MPL) implementation of the H.323 Voice over IP protocol. The code is written in C++ and, through the development effort of numerous people around the world, fully supports the H.323 protocol. The software has been integrated into a number of open source and commercial software products. Software published under the OpenH323 project includes The implementation of VoIP protocols * PTLib - a multi-platform C++ class library. Programs based on PTLib can run on both Microsoft Windows and Unix/Linux. The library contains both the “basic” classes (strings, arrays, lists) and the higher-level functionality (networking, multi-threading). * H323Plus – a library for the development of H.323 applications. It uses PTLib for platform independence. The library has its own ASN.1 parser that generates the classes for encoding and decoding of the protocol messages used in H.323. Sample network ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Gatekeeper
GNU Gatekeeper (abbreviated as GnuGk) is a free software project that implements an H.323 Gatekeeper based on the OpenH323 or H323Plus stack. A gatekeeper provides address translation, admissions control, call routing, authorization and accounting services to an H.323 system defined on the H.323 standard by ITU-T. Features GnuGk's set of features include: * Created for Linux, Windows, macOS, Solaris (operating system), Solaris, FreeBSD, OpenBSD and NetBSD * A policy-based flexible routing mechanism * Calling and called numbers rewriting, including CLI rewriting * Full H.323 proxy, including Real-time Transport Protocol (RTP) and RTP Control Protocol (RTCP) media channels, and T.120 data channels * NAT traversal using a number of protocols, including H.460.17, H.460.18 and H.460.19 * IPv6 support (incl. IPv4-IPv6 proxying) * LDAP directory support (H.350) * Call retry-failover * Clustering support by neighbors, parent-child, alternates GK * Transmission Control Protocol (TCP) status ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mozilla Public License
The Mozilla Public License (MPL) is a free and open-source weak copyleft license for most Mozilla Foundation software such as Firefox and Thunderbird The MPL license is developed and maintained by Mozilla, which seeks to balance the concerns of both open-source and proprietary developers; it is distinguished from others as a middle ground between the permissive software BSD-style licenses and the General Public License. So under the terms of the MPL, it allows the integration of MPL-licensed code into proprietary codebases, but only on condition those components remain accessible. MPL has been used by others, such as Adobe to license their Flex product line, and The Document Foundation to license LibreOffice 4.0 (also on LGPL 3+). Version 1.1 was adapted by several projects to form derivative licenses like Sun Microsystems' Common Development and Distribution License. It has undergone two revisions: the minor update 1.1, and a major update version 2.0 nearing the goals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Over IP
Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of speech, voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet telephony, broadband telephony, and broadband phone service specifically refer to the provisioning of communications services (voice, fax, Short Message Service, SMS, voice-messaging) over the Internet, rather than via the public switched telephone network (PSTN), also known as plain old telephone service (POTS). Overview The steps and principles involved in originating VoIP telephone calls are similar to traditional digital telephony and involve signaling, channel setup, digitization of the analog voice signals, and encoding. Instead of being transmitted over a circuit-switched network, the digital information is packetized and transmission occurs as IP packets over a packet-switched network. They transport media streams using spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstract Syntax Notation One
Abstract Syntax Notation One (ASN.1) is a standard interface description language for defining data structures that can be serialized and deserialized in a cross-platform way. It is broadly used in telecommunications and computer networking, and especially in cryptography. Protocol developers define data structures in ASN.1 modules, which are generally a section of a broader standards document written in the ASN.1 language. The advantage is that the ASN.1 description of the data encoding is independent of a particular computer or programming language. Because ASN.1 is both human-readable and machine-readable, an ASN.1 compiler can compile modules into libraries of code, codecs, that decode or encode the data structures. Some ASN.1 compilers can produce code to encode or decode several encodings, e.g. packed, BER or XML. ASN.1 is a joint standard of the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) in ITU-T Study Group 17 and ISO/IEC, orig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSTN
The public switched telephone network (PSTN) provides infrastructure and services for public telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local telephony operators. These consist of telephone lines, fiber optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables, all interconnected by switching centers which allow most telephones to communicate with each other. Originally a network of fixed-line analog telephone systems, the PSTN is now almost entirely digital in its core network and includes mobile and other networks, as well as fixed telephones. The technical operation of the PSTN adheres to the standards created by the ITU-T. These standards allow different networks in different countries to interconnect seamlessly. The E.163 and E.164 standards provide a single global address space for telephone numbers. The combinat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Phone Abstraction Library
In the field of VoIP networking, the Open Phone Abstraction Library (OPAL) continues the open-source openh323 project to support a wide range of commonly used protocols used to send voice, video and fax data over IP networks rather than being tied to the H.323 protocol. Initially, from 2007, OPAL supported the H.323 and Session Initiation Protocol (SIP) protocols, but it has grown to include Asterisk IAX2. About OPAL implements a wide range of Voice over IP (VoIP) protocols for voice, video and fax data over IP networks. It is written in C++ and released under the Mozilla Public Licence. OPAL utilises the PTLib portable library that allows OPAL to run on a variety of platforms including Unix/Linux/BSD, MacOSX, Windows, Windows mobile and embedded systems. Opal was developed as a derivative of the OpenH323 The OpenH323 project had as its goal the development of a full featured, open source ( MPL) implementation of the H.323 Voice over IP protocol. The code was written in C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
