IPX/SPX

IPX/SPX stands for Internetwork Packet Exchange/Sequenced Packet Exchange. IPX and SPX are networking protocols used primarily on networks using the Novell NetWare operating systems.

Protocol layers

IPX and SPX are derived from Xerox Network Systems' IDP and SPP protocols, respectively. IPX is a network layer protocol (layer 3 of the OSI Model), while SPX is a transport layer protocol (layer 4 of the OSI Model). The SPX layer sits on top of the IPX layer and provides connection-oriented services between two nodes on the network. SPX is used primarily by client–server applications.

IPX and SPX both provide connection services similar to TCP/IP, with the IPX protocol having similarities to IP, and SPX having similarities to TCP. IPX/SPX was primarily designed for local area networks (LANs), and is a very efficient protocol for this purpose (typically its performance exceeds that of TCP/IP on a LAN ). TCP/IP has, however, become the de facto standard protocol. This is in part due to its superior performance over wide area networks and the Internet (which uses TCP/IP exclusively), and also because TCP/IP is a more mature protocol, designed specifically with this purpose in mind.

Speex

Speex is an audio compression format designed for speech and also a free software speech codec that may be used on VoIP applications and podcasts. It is based on the CELP speech coding algorithm. Speex claims to be free of any patent restrictions and is licensed under the revised (3-clause) BSD license. It may be used with the Ogg container format or directly transmitted over UDP/RTP.

The Speex designers see their project as complementary to the Vorbis general-purpose audio compression project.

Speex is a lossy format, meaning quality is permanently degraded to reduce file size.

The Speex project was created on February 13, 2002. The first development versions of Speex were released under LGPL license, but as of version 1.0 beta 1, Speex is released under Xiph's version of the (revised) BSD license. Speex 1.0 was announced on March 24, 2003, after a year of development. The last stable version of Speex encoder and decoder is 1.1.12.

Xiph.Org now considers Speex obsolete; its successor is the more modern Opus codec, which surpasses its performance in all areas.

Mossberg 930

The Mossberg 930 is a 12-gauge semi-automatic shotgun designed by O.F. Mossberg & Sons.

The Mossberg 930 is one of the most popular automatic shotguns, used by hunters and skeet-shooters often.

Design

The Mossberg 930 is gas operated, which means that some of the hot gases from the burning gunpowder are used to push a piston that operates the action, ejecting the spent hull and chambering a fresh shell. This gas action reduces the recoil felt by the shooter. Like other Mossberg shotguns, this shotgun has an ambidextrous safety that is located on the rear of the receiver. The Mossberg 930 takes 2¾" or 3" shells and can be accessorized with shell catchers, Picatinny rails, special muzzle brakes for door breaching, etc.

References

External links

SPX

SPX can refer to:

IPX (disambiguation)

IPX may refer to:

IP Code

The IP Code, International Protection Marking, IEC standard 60529, sometimes interpreted as Ingress Protection Marking, classifies and rates the degree of protection provided against intrusion (body parts such as hands and fingers), dust, accidental contact, and water by mechanical casings and electrical enclosures. It is published by the International Electrotechnical Commission (IEC).

The standard aims to provide users more detailed information than vague marketing terms such as waterproof. The digits (characteristic numerals) indicate conformity with the conditions summarized in the tables below. Where there is no data available to specify a protection rating with regard to one of the criteria, the digit is replaced with the letter X. The digit 0 is used where no protection is provided.

A rating of X for one or more of the protection criteria can be erroneously misinterpreted as "no protection." To illustrate, a piece of electronic equipment rated IPX7 will almost certainly demonstrate a robust resistance to the ingress of particles, even though a rating for ingress of solids hasn't been formally assigned. Hence, an X designation shouldn't be automatically misconstrued as a lack of protection.

Internetwork Packet Exchange

Internetwork Packet Exchange (IPX) is the network layer protocol in the IPX/SPX protocol suite. IPX is derived from Xerox Network Systems' IDP. It may act as a transport layer protocol as well.

The IPX/SPX protocol suite was very popular through the late 1980s into the mid-1990s because it was used by the Novell NetWare network operating system. Because of Novell Netware popularity the IPX became a prominent internetworking protocol.

A big advantage of IPX was a small memory footprint of the IPX driver, which was vital for MS-DOS and Microsoft Windows up to the version Windows 95 because of limited size of the conventional memory. Another IPX advantage is an easy configuration of the client computers. However, IPX does not scale well for large networks such as the Internet, and as such, IPX usage decreased as the boom of the Internet made TCP/IP nearly universal. Computers and networks can run multiple network protocols, so almost all IPX sites will be running TCP/IP as well to allow for Internet connectivity. It has also been possible to run Novell products without IPX for some time, as they have supported both IPX and TCP/IP since NetWare reached version 5 in late 1998.