Packet over SONET/SDH, abbreviated POS, is a communications protocol for transmitting packets in the form of the Point to Point Protocol (PPP) over SDH or SONET, which are both standard protocols for communicating digital information using lasers or light emitting diodes (LEDs) over optical fibre at high line rates. POS is defined by RFC 2615 as PPP over SONET/SDH. PPP is the Point to Point Protocol that was designed as a standard method of communicating over point-to-point links. Since SONET/SDH uses point-to-point circuits, PPP is well suited for use over these links. Scrambling is performed during insertion of the PPP packets into the SONET/SDH frame to solve various security attacks including denial-of-service attacks and the imitation of SONET/SDH alarms. This modification was justified as cost-effective because the scrambling algorithm was already used by the standard used to transport ATM cells over SONET/SDH. However, scrambling can optionally be disabled to allow a node to be compatible with another node that uses the now obsoleted RFC 1619 version of Packet over SONET/SDH which lacks the scrambler.
The most important application of POS is to support sending of IP packets across wide area networks. Large amounts of traffic on the Internet are carried over POS links. POS is also one of the link layers used by the Resilient Packet Ring standard known as IEEE 802.17.
History of POS
Cisco was involved in making POS an important wide area network protocol. PMC-Sierra produced an important series of early semiconductor devices which implemented POS.
Details about the name "POS"
POS (packet over SONET) is a double-nested abbreviation. The S represents "SONET/SDH", which itself stands for "Synchronous Optical Network/Synchronous Digital Hierarchy". Given this information, POS technically stands for "Packet over Synchronous Optical Network/Synchronous Digital Hierarchy".
Complementary Interfaces
The System Packet Interface series of standards from the Optical Internetworking Forum including SPI-4.2 and SPI-3 and their predecessors PL-4 and PL-3 are commonly used as the interface between packet processing devices and framer devices that implement POS. The acronym PL-4 means POS-PHY Layer 4.
packet, over, sonet, this, article, multiple, issues, please, help, improve, discuss, these, issues, talk, page, learn, when, remove, these, template, messages, this, article, needs, additional, citations, verification, please, help, improve, this, article, ad. This article has multiple issues Please help improve it or discuss these issues on the talk page Learn how and when to remove these template messages This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Packet over SONET SDH news newspapers books scholar JSTOR February 2011 Learn how and when to remove this template message This article does not cite any sources Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Packet over SONET SDH news newspapers books scholar JSTOR June 2022 Learn how and when to remove this template message Learn how and when to remove this template message Packet over SONET SDH abbreviated POS is a communications protocol for transmitting packets in the form of the Point to Point Protocol PPP over SDH or SONET which are both standard protocols for communicating digital information using lasers or light emitting diodes LEDs over optical fibre at high line rates POS is defined by RFC 2615 as PPP over SONET SDH PPP is the Point to Point Protocol that was designed as a standard method of communicating over point to point links Since SONET SDH uses point to point circuits PPP is well suited for use over these links Scrambling is performed during insertion of the PPP packets into the SONET SDH frame to solve various security attacks including denial of service attacks and the imitation of SONET SDH alarms This modification was justified as cost effective because the scrambling algorithm was already used by the standard used to transport ATM cells over SONET SDH However scrambling can optionally be disabled to allow a node to be compatible with another node that uses the now obsoleted RFC 1619 version of Packet over SONET SDH which lacks the scrambler Contents 1 Applications of POS 2 History of POS 3 Details about the name POS 4 Complementary Interfaces 5 See alsoApplications of POS EditThe most important application of POS is to support sending of IP packets across wide area networks Large amounts of traffic on the Internet are carried over POS links POS is also one of the link layers used by the Resilient Packet Ring standard known as IEEE 802 17 History of POS EditCisco was involved in making POS an important wide area network protocol PMC Sierra produced an important series of early semiconductor devices which implemented POS Details about the name POS EditPOS packet over SONET is a double nested abbreviation The S represents SONET SDH which itself stands for Synchronous Optical Network Synchronous Digital Hierarchy Given this information POS technically stands for Packet over Synchronous Optical Network Synchronous Digital Hierarchy Complementary Interfaces EditThe System Packet Interface series of standards from the Optical Internetworking Forum including SPI 4 2 and SPI 3 and their predecessors PL 4 and PL 3 are commonly used as the interface between packet processing devices and framer devices that implement POS The acronym PL 4 means POS PHY Layer 4 See also EditEthernet over SONET This computer networking article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Packet over SONET SDH amp oldid 1096130546, wikipedia, wiki, book, books, library,
