NETWORKING I

COLLISION - is an isolated event in which two or more bodies (colliding bodies) exert relatively strong forces on each other for a relatively short time.


TYPES OF COLLISIONS

1. LOCAL COLLISION - in CSMA/CD computer networks, is a collision that occurs at the NIC as opposed to on the wire. On UTP cable a local collision is detected on the local segment only when a station detects a signal on the RX pair at the same time it is sending on the TX pair.

2. REMOTE COLLISION - in CSMA/CD computer networks, is a collision that occurs when a frame having length less than minimum length and with an incorrect FCS (Frame Check Sequence), is transmitted. This frame causes a collision at the remote end which will not be detected by the transmitter.

3. LATE COLLISION - is a type of collision found in the CSMA/CD protocol standard. If a collision error occurs after the first 512 bit times of data are transmitted by the transmitting station, a late collision is said to have occurred. Importantly, late collisions are not re-sent by the NIC unlike collisions occurring before the first 64 octets; it is left for the upper layers of the protocol stack to determine that there was loss of data.

JABBER - is an initiative to produce an open source, XML-based instant messaging platform. Similar to the Linux and Apache projects, Jabber developers volunteer their time to work with the code over the Internet.

COLLISION DOMAIN - is a physical network segment where data packets can "collide" with one another for being sent on a shared medium, in particular in the Ethernet networking protocol. This is an Ethernet term used to describe a network scenario wherein one particular device sends a packet on a network segment, forcing every other device on that same segment to pay attention to it.

MULTIMODE FIBER (multimode fiber or MM fiber or fibre) - is a type of optical fiber mostly used for communication over shorter distances, such as within a building or on a campus. Typical multimode links have data rates of 10 Mbit/s to 10 Gbit/s over link lengths of up to 600 meters—more than sufficient for the majority of premises applications.

SINGLE-MODE FIBER (SMF) - is an optical fiber designed to carry only a single ray of light (mode). This ray of light often contains a variety of different wavelengths. Although the ray travels parallel to the length of the fiber, it is often called the transverse mode since its electromagnetic vibrations occur perpendicular (transverse) to the length of the fiber. Single-mode optical fibers are also called monomode optical fibers, single-mode optical waveguides, or unimode fibers.


PICTURE FOR LOOSE - TUBE FIBER














PICTURE FOR TIGHT - BUFERRED FIBER