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Picture of Darren Shurmer (admin)

Darren Shurmer (admin)

Hidden Node Problem

In wireless networks, the hidden node problem occurs when there are two clients on either side of an access point which are within range of the access point, but which can't actually hear each other's transmissions. In this situation both clients may simultaneously transmit data, resulting in collisions at the access point, which is unable to interpret either signal.

High Definition

High resolution TV standard of 1920 x 1080 pixels (about 2.1 million pixels per colour) which is very close to the minimum cinema 2K resolution format at 2048 x 1080 pixels (2.2 million pixels per colour). As HDTV expands, it will increasingly threaten those cinemas offering 2Kquality.

High Level Data Link Control (HDLC)

High Level Data Link Control (HDLC) is a Layer 2 protocol developed by the International Organization for Standardization for use on point-to-point communication links. HDLC was a precursor to PPP.

Highlight Compensation (HLC)

The HLC function detects any strong light spots such as car headlights and flashlights in the dark and masks them in the captured images. This can relieve operator eye strain, making the monitoring task easier.

Host Number

The host number is the second part of a Layer 3 address. (The network number is the first part.) The host number portion of the Layer 3 address identifies the unique device on a network. Both the network number and host number are assigned by a network administrator.

HPoE+ (HPoE Plus)

HPoE+ enables devices to receive power (up to 60 W) from HPoE+-enabled equipment such as a PowerDsine 9501GB power injector from Microsemi Corporation through the same Ethernet cable that transports data by using 4 wires. HPoE+ is useful especially for PTZ, Rapid Dome cameras that require motor control, and outdoor dome cameras that operate a heater in low temperature conditions.

HPoE/PoE+ (High PoE/PoE Plus, IEEE 802.3at)

HPoE/PoE+ enables networked devices to receive power (up to 25.5 W) from HPoE/PoE+-enabled equipment through the same Ethernet cable that transports data. HPoE/PoE+ is useful especially for PTZ/Rapid Dome cameras that require motor control, and outdoor dome cameras that operate a heater in low- temperature conditions.

HTTP

The Hypertext Transfer Protocol (HTTP) is a communications protocol for the transfer of information on the Internet and the World Wide Web.

HTTP port

A port used to communicate between the web server and the web client such as a web browser.

Hub

A hub is a Layer 1 device that takes a signal that it receives from one connected device and passes it along or repeats it to all other connected devices. A hub allows each device to use its own twisted-pair cable to connect to a port on the hub. If a cable fails, it will impact only one device, and if one device is causing trouble on the network, that individual device can easily be unplugged. A hub is not an intelligent network device. It does not look at the MAC addresses or data in the Ethernet frame and does not perform any type of filtering or routing of the data. It is simply a junction that joins all the different devices together. Even though each device has its own cable connecting it to the hub, access to the network still operates by CSMA/CD, and collisions can occur on the shared bus inside the hub.

Hypertext Markup Language (HTML)

Hypertext Markup Language (HTML) is the language the Web browser and Web server use to create and display Web pages.

ICANN

The Internet Corporation for Assigned Names and Numbers (ICANN) is the current organization that is responsible for all IP address assignment and domain name registration. ICANN assumed control of IANA in 1998.

IK10

The IK rating system (defined in the IEC 62262 standard) classifies the level of protection provided by electrical appliances against external impacts (i.e. physical impact on the outside of the camera). An IK10-rated camera is capable of withstanding the impact of 20 joules; this is equivalent to withstanding the impact of a 5 kg weight dropped from a height of 40 cm.

IK8

The IK rating system (defined in the IEC 62262 standard) classifies the level of protection provided by electrical appliances against external impacts (i.e. physical impact on the outside of the camera). An IK8-rated camera is capable of withstanding the impact of 5 joules; this is equivalent to withstanding the impact of a 1.7 kg weight dropped from a height of 29.5 cm.

Indirect Routing

Indirect Routing is communication between devices with the help of a router.

Intelligent Cropping

Intelligent Cropping is a function to observe specific areas of interest* in any captured image with a 4K resolution, while overviewing the entire image with a lower Full HD resolution. It can reduce the data size by up to 50% to efficiently manage network bandwidth and storage costs. This function provides a Full HD resolution overview, in parallel with four separate close-ups at a VGA-cropped view or two separate close-ups at Full HD with an original 4K resolution. * The specific areas of interest can be selected from Static (fixed area) or Dynamic (movable area in combined use with a Multi Tracking function).

Intelligent Scene Capture

Intelligent Scene Capture is a function to provide the best picture quality for the scene. It analyses captured images and automatically adjusts parameters such as shutter speed and gain, responding to environmental factors such as weather, time, and lighting conditions. In addition to Standard mode, you can select Motion Priority mode (ideal for capturing moving objects) and Low Noise Priority mode (ideal for noise Capture modes and manual setting modes.

Interface ID

In IPv6, the interface ID is the host portion of the address that follows the network prefix.

Internet Assigned Numbers Authority (IANA)

The Internet Assigned Numbers Authority (IANA) is the organization that centrally managed the global IP address space.

Internet Layer

In the TCP/IP Reference Model, the Internet Layer receives a segment from the Transport Layer, adds a header to it to create a packet, and sends the packet to the Network Access Layer. The Internet Layer is responsible for delivering the packet to the destination computer. If there is more than one route to the destination computer, the Internet Layer chooses the best path for the packet to take. The Internet Layer treats each packet independently, so it is possible that two packets from the same transmission might take different paths to arrive at the destination computer. This is the same as the OSI Reference Model Network Layer and the Five-Layer Model Network Layer.

Internet Layer/Layer 3

This definition is out of date. Please report any links to it as bugs. It should now link to the Network Layer.

Internet Protocol (IP)

The Internet Protocol (IP) is the most common Layer 3 protocol and is used within the Internet to route packets to their final destination. IP provides connectionless, best-effort delivery of packets through a network and fragmentation and reassembly of packets going across Layer 2 networks with different maximum transmission units (MTUs). Each computer or host has at least one IP address that uniquely identifies it from all other computers on the Internet. The IP addressing scheme is fundamental to the process of routing packets through a network.

Internet Service Provider (ISP)

An Internet Service Provider (ISP) is a company or organization that has the network equipment and communication lines to provide connectivity to the Internet for customers.

Internet Stream Protocol

Internet Stream Protocol, which was considered by some to be IP Version 5, was developed between IPv4 and IPv6 and never made it past experimental stages.

Intranet

An intranet is a private, internal network that uses the sameIP-based protocols used in the Internet. Intranets often use IP addresses from the private IP address space.

IP66

The 'IP' of IP66 stands for ingress protection (defined in the IEC 605292 standard), and its two-digit number shows the durability rating of equipment for outdoor use. The first digit of IP66 relates to ingress protection against dust, and '6' means 'dust tight'. The second digit of IP66 relates to ingress protection against water, and '6' means protected against 'heavy jet sprays', such as conditions encountered during hurricanes.

IP address

Abbreviation for Internet Protocol Address. An individual IP address is basically assigned to each piece of equipment connected to the Internet.

IP Control Protocol (IPCP)

IP Control Protocol (IPCP) is the PPP Network Control Protocol used to configure, enable, and disable the IP protocol on both ends of the point-to-point link.

IP Datagram

IP datagram is a synonym for an IP packet, which is the data combined with the IP header.

IP Interfaces

IP interfaces are Layer 3 software interfaces or ports that work with the hardware interface or port.

IP Version 4 (IPv4)

IP Version 4 (IPv4) is currently the most commonly used version of the IP protocol. It consists of a 32-bit address and allows for about 4.3 billion unique addresses.

IP Version 6 (IPv6)

IP Version 6 (IPv6) is the next-generation version of the IP protocol. It consists of a 128-bit address, supports more levels of addressing hierarchy, and provides a much greater supply of addresses than IPv4.

IR Illuminator

The IR illuminators built into our cameras consist of multiple high- performance IR LEDs located around the camera lens; this enables each camera to project powerful and uniform IR light to a great distance. Combined with the True D/N function, IR illuminators enable each camera to produce clear B/W images even in complete darkness (0 lx).

Java applet

A program written in Java language that can be used in the web browser.

Java Virtual Machine

Software that transfers the Java applet's byte code to the native code of your system to execute it.

JPEG

Abbreviation for Joint Photographic Expert Group. The still image compression technology or standards of the ISO (International Organization for Standardization) and ITU-T. Popularly used as image compression format on the Internet, etc.

JPEG2000

The new compression standard using "wavelet" technology that has been chosen by the DCI for compression of movie files. This replaces the use of MPEG compression in DCI compliant D-cinema

KDM

Key Delivery Message. See Key

Keepalives

Keepalives are the periodic messages two devices exchange to maintain a connection.

Key

Electronic data file that allows encrypted movie files to be unlocked. This sent to the cinema to allow the encrypted movie on their server to be opened.

Key Delivery Message (KDM)

Contains all of the keys necessary to allow the playback of a composition on a specific server during a certain time period. The KDM is ordered by a specific CPL ID#. The KDM is delivered separately from the DCP shipment that it is associated with

Label Edge Router (LER)

A Label Edge Router (LER) is a special type of ingress or egress LSR that is responsible for assigning the appropriate MPLS label to a packet.

Label Switched Paths (LSPs)

Label Switched Paths (LSPs) are the unidirectional paths used to connect each location in an MPLS network.

Label Switching Routers (LSRs)

Label Switching Routers (LSRs) are routers running the MPLS protocol.

LAN

Any group of computers on a single, geographically limited network is a called a local area network (LAN). LANs allow users to exchange documents and share resources such as printers or file servers. A LAN can be either wired or wireless, or a combination of both.

Layer 2 Address

When sending data on a network, Layer 2 addresses identify the stops made along the way, and not the communicating computers or endpoints. Layer 2 addresses change with each stop along the route to the final destination. A Layer 2 address is also known as a MAC address, a hardware address, or a physical address.

Layer 3 Address

A Layer 3 address identifies a unique destination. A network administrator assigns each computer on a network a unique Layer 3 address. The destination and source Layer 3 addresses identify the communicating computers or end points. A Layer 3 address is also known as an IP address or a logical address.

Layer 3 MPLS VPNs or IP VPNs

Layer 3 MPLS VPNs or IP VPNs define a way for providers to use their IP backbone to provide IP-based VPN services regardless of what Layer 2 technology is in use. Layer 3 MPLS VPNS use label switched paths to interconnect different customer locations and keep traffic separated. Customer edge routers exchange IP routing information with the provider's routers where it is stored in a virtual router and forwarding table. Provider Edge routers exchange routes with other provider edge routers within the VPN. When IP packets enter the MPLS network, the provider edge router determines which LSP to use to based on the routing information in the virtual router and forwarding table .

Leased Line

A leased line is a pre-established communications path between two locations with a fixed amount of bandwidth-whether or not it is used. Leased lines are owned by the service provider and not by the customer.

Link Control Protocol (LCP)

Link Control Protocol (LCP) packets are the packets exchanged between two devices during the PPP connection establishment process.

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