Switching

Switching is what is done by a switch.

Switching may also refer to:

See also

Packet switching

Packet switching is a digital networking communications method that groups all transmitted data into suitably sized blocks, called packets, which are transmitted via a medium that may be shared by multiple simultaneous communication sessions. Packet switching increases network efficiency, robustness and enables technological convergence of many applications operating on the same network.

Packets are composed of a header and payload. Information in the header is used by networking hardware to direct the packet to its destination where the payload is extracted and used by application software.

Starting in the late 1950s, American computer scientist Paul Baran developed the concept Distributed Adaptive Message Block Switching with the goal to provide a fault-tolerant, efficient routing method for telecommunication messages as part of a research program at the RAND Corporation, funded by the US Department of Defense. This concept contrasted and contradicted the theretofore established principles of pre-allocation of network bandwidth, largely fortified by the development of telecommunications in the Bell System. The new concept found little resonance among network implementers until the independent work of Donald Davies at the National Physical Laboratory (United Kingdom) (NPL) in the late 1960s. Davies is credited with coining the modern name packet switching and inspiring numerous packet switching networks in Europe in the decade following, including the incorporation of the concept in the early ARPANET in the United States.

CCNA

CCNA (Cisco Certified Network Associate) is an IT certification from Cisco.

CCNA certification is an associate-level Cisco Career certification.

The Cisco exams have changed several times. In 2013, Cisco announced an update to its certification program that "aligns certification and training curricula with evolving industry job roles." There are now several different types of Cisco-Certified Network Associate, with "CCNA Routing and Switching" being closest to the original CCNA focus; other types of CCNA focus on security, collaboration, datacentres, service providers, video, voice, and wireless.

The content of the exams is proprietary. Cisco and its learning partners offer a variety of different training methods, including books published by Cisco Press, and online and classroom courses available under the title "Interconnecting Cisco Network Devices."

To achieve CCNA Routing and Switching certification, one must earn a passing score on Cisco exam #200-120, or combined passing scores on both the "Interconnecting Cisco Network Devices" ICND1 #100-101 and ICND2 #200-101 exams. Passing the ICND1 grants one the Cisco Certified Entry Networking Technician (CCENT) certification. Passing scores are set by using statistical analysis and are subject to change. At the completion of the exam, candidates receive a score report along with a score breakout by exam section and the passing score for the given exam. Cisco does not publish exam passing scores because exam questions and passing scores are subject to change without notice.

And I

"And I" is a song written by American R&B singer Ciara, and produced by Adonis Shropshire for Ciara's first album, Goodies (2004). It was released as the album's fourth and final single on August 30, 2005 (see 2005 in music) in North America.

The song was originally the third choice for the fourth single. Ciara has mentioned in an interview that "Thug Style", "Hotline" or "Pick up the Phone" would be the fourth single, but when Ciara suggested "And I" to executives at her previous record label LaFace, they were unhappy because they wanted "Next to You" to be the fourth single.

Chart performance

At the time of the U.S. release of "And I", Ciara's collaboration with Bow Wow, "Like You", and her collaboration with Missy Elliott, "Lose Control", were at the height of their popularity. "And I" peaked at 96 on the U.S. Billboard Hot 100 and 27 on Billboard's Hot R&B/Hip-Hop Singles & Tracks chart, which were poor positions compared to those attained by the first three singles from the album Goodies. It was not released outside North America because of this, and it is Ciara's least successful single.