We make a simple clearance of the communication skills:
1. Core algorithm software: Mainly some audio, video encoding, decoding class software, such software may adopt assembly or C language, run on some industrial grade microprocessors such as ARM and DSP, the operating system is a dedicated operating system or RTOS (such as VxWorks, PSOS, etc.).
2, Signaling Protocol Stack Software: Mainly used for equipment intercommunication, network interconnection, etc. Communication networks are constantly updating, developing, and communication protocols are also evolving. This type of software is running on the switch, and the operating system may be an embedded system or some universal systems such as UNIX and Windows.
3. Operation support software: also known as the BOSS system, mainly to provide operators with billing, settlement, business, etc., is the core software of the operator. Such software runs on a normal server, the operating system may be UNIX or NT, etc.
4, value-added application software: mainly based on some value-added applications developed by some kinds of switches or boards, such as call centers, conference calls, etc., or some telecom service software developed by some third service providers (such as current common SMS , Color, or secretary-based business, etc.).
The first two types of software is relatively mature due to strong versatility, technology and standards are relatively mature, and is the main development field of current communication open source projects. Below, we have the second type of communication software, which is the second type of communication software, which is the second type of communication software, which is the second type of communication software, to simply describe the current situation of open source software in the communication industry.
Open source seven signaling protocol stack -OpenSS7
Seventh signaling is the most common signaling system interconnected between telecomnets. It is like TCP / IP. In various telecommunications network structures, you can see the figure of the seventh signaling.
OpenSS7 is an open source protocol stack project that supports seven signaling (SS7) and SigTRAN under the dominant OpenSS7 company. The project started in 1996, it implements the seven SMS system in the ITUQ.700 series of recommendations. With the rise of VoIP and softswitch, the focus of OpenSS7 focuses on the implementation of the SigTran protocol (SigTRAN can be seen as the NGN version of SS7). In fact, OpenSS7 is actually limited to seven signaling, ISDN and soft exchange of signaling are within its consideration.
For details on OpenSS7, please refer to the "No. 7 Signaling Open Source Project -OpenSS7 Architecture"
Note that OpenSS7 does not belong to the free software. If you need to use OpenSS7 for commercial purposes, you need to pay a certain license fee to OpenSS7.
Open source SIP protocol stack -vocal, OSIP
SIP is a communication protocol for a user IP phone proposed by IETF, which is used to establish, change, and terminate calls between users based on IP networks. The protocol is based on the protocols such as SMTP (Simple Mail Transfer Protocol) and HTTP (Hyper Text Transfer Protocol). In order to provide telephone services, it also needs to be combined with several other standards and protocols: especially need to ensure transmission (RTP), interconnects with the current telephone network, can ensure voice quality (RSVP), can provide directory (LDAP) , You can authenticate users (RADIUS), and the like.
Since it is a telephone standard proposed by the computer world, it reveals many of the features of many computer industry, for example, it uses existing protocols as much as possible, rather than rebuilding standards, such as HTTP, LDAP, RADIUS, etc. Technical maturity, extensive application of extensive agreement. Second, its development is relatively difficult than other protocol stacks (such as its competition protocol H.323), and the relevant open source projects are more, such as Vocal, OSIP is more mature, commercially available SIP protocol. Stack. Vocal (ie VOVIDA Open Source Communication Application) It is a set of SIP protocol stacks developed by the VOVIDA community. OSIP is a SIP protocol stack software developed by the Old Second Source Community GNU, which is based on both protocol stacks. A simple comparison:
Open source H.323 protocol stack -Openh323
H.323 and SIP together, and become two major criteria in the VoIP field. Different is that the SIP is defined by the computer boundf, and H.323 is defined by the telecommunications (ITU). From the application, SIP is more suitable for enterprise applications, while H.323 is more suitable for telecommunications applications. From the difficulty of development, H.323 is much more complicated than SIP. If you want to start from scratch, its development cycle will have a long time. However, there is OpenH323, everything is different, we can make a set of telecommunications VoIP systems in the short term.
OpenH323 is a communication protocol stack software for the largest development source code in communication. The project is developed by EquivalencePtytd, Australia. It has begun from 1998 to the end of 2000, the basic H.323 protocol framework has been realized, mainly Free software developers who want to engage in VoIP and network video, this protocol library is fully compliant with H.323 protocol, can communicate with any software that meets the protocol, such as Microsoft's NetMeeting, etc. Many commercial H.323 protocol stacks are based on OpenH323 basis.
The advantage of OpenH323 is that it is relatively complete implementation of ITU's recommendations for H.323, enabling IP-based various telephone applications, including voice, video, conference, and faxes. Through this protocol stack, we can easily customize all kinds of H.323 entities such as terminals, gatekeepers, gateways, or MCUs they need. Moreover, it does not require any payment, which has a lot of temptation to commercial users and individual developers.
OpenH.323 supports but pre-popular various platforms, including Linux, Windows, and MacOS and UNIX, programming languages use object-oriented C languages. For specific technical details, please refer to Lu Zheng's "How to successfully use OpenH323 to develop commercial H.323 protocol stack".
to sum up
One of the purposes of communication software is to reduce the threshold of communication technology, popularize communication knowledge, and let some core technologies in the communication industry can be mastered, use, and also reduce the investment of repeated development of communication projects, so It is very important. However, the number of open source projects in the communication industry is limited, and it can be truly used by people. Therefore, there is a need for more communication-specific people to participate in this area, so that open source ideas can also root root in the field of communication.
Source: Communication World
