Network + certmaster q and a

What are network protocols and what are its two functions?

A network protocol is a set of rules for exchanging data in a structured format. A network protocol has two principal functions: Addressing-Describing where data messages should go. At each layer, there are different mechanisms for identifying nodes and rules for how they can send and receive messages. Encapsulation-Describing how data messages should be packaged for transmission. Encapsulation is like an envelope for a letter, with the distinction that each layer requires its own envelope. At each layer, the protocol adds fields in a header to whatever data (payload) it receives from an application or other protocol.

What is backbone cabling?

Backbone Cabling-Connects horizontal cross-connects (HCCs) to the main cross-connect (optionally via intermediate cross-connects). These can also be described as vertical cross-connects, because backbone cabling is more likely to run up and down between floors.

What are the media types of the physical layer?

Cabled-A physical signal conductor is provided between two nodes. Examples include cable types such as copper or fiber optic cable. Cabled media can also be described as bounded media. Wireless-Uses free space between nodes, such as microwave radio. Wireless media can also be described as unbounded media.

What is the significance of a collision domain to networking?

Each network node connected to the same media is in the same collision domain. When two nodes transmit at the same time, the signals are said to collide and neither signal can reach its destination. This means that they must be sent again, reducing available bandwidth. The collisions become more frequent as more nodes are added, and consequently the effective data rate is reduced.

What are enterance facilities/Demarc.

Entrance Facilities/Demarc-Special types of equipment rooms marking the point at which external cabling (outside plant) is joined to internal (premises) cabling. These are required to join the access provider's network and for inter-building communications. The demarcation point is where the access provider's network terminates and the organization's network begins.

What is horizontal cabling?

Horizontal Cabling-Connects user work areas to the nearest horizontal cross-connect. A cross-connect can also be referred to as a distribution frame. Horizontal cabling is so-called because it typically consists of the cabling for a single floor and so is made up of cables run horizontally through wall ducts or ceiling spaces.

What is Mechanical Transfer Registered Jack (MTRJ) fiber optic cabling?

Mechanical Transfer Registered Jack (MTRJ) is a small-form-factor duplex connector with a snap-in design used for multimode networks.

What is Multimode Fiber (MMF)?

Multimode Fiber (MMF) has a larger core (62.5 or 50 microns) and shorter wavelength light (850 nm or 1300 nm) transmitted in multiple waves of varying length. MMF uses less expensive optics and consequently is less expensive to deploy than SMF. However, it does not support such high signaling speeds or long distances as single mode and so is more suitable for LANs than WANs.

What devices operate at the data link layer?

Network adapter or network interface card (NICs)-A NIC joins an end system host to network media (cabling or wireless) and enables it to communicate over the network by assembling and disassembling frames. Bridge-A bridge is a type of intermediate system that joins physical network segments while minimizing the performance reduction of having more nodes on the same network. A bridge has multiple ports, each of which functions as a network interface. Switch-An advanced type of bridge with many ports. A switch creates links between large numbers of nodes more efficiently. Wireless access point (AP)-An AP allows nodes with wireless network cards to communicate and creates a bridge between wireless networks and wired ones.

What is OM1/OM2

OM1/OM2-62.5-micron cable is OM1, while early 50-micron cable is OM2. OM1 and OM2 are mainly rated for applications up to 1 Gbps and use LED transmitters.

What is OM3/OM4?

OM3/OM4-these are also 50-micron cable, but manufactured differently, designed for use with 850 nm Vertical-Cavity Surface-Emitting Lasers (VCSEL), also referred to as laser optimized MMF (LOMMF). A VCSEL is not as powerful as the solid-state lasers used for SMF, but it supports higher modulation (transmitting light pulses rapidly) than LED-based optics.

What are the specifications of the physical layer?

Physical topology-The layout of nodes and links as established by the transmission media. An area of a larger network is called a segment. A network is typically divided into segments to cope with the physical restrictions of the network media used, to improve performance, or to improve security. At the Physical layer, a segment is where all the nodes share access to the same media. Physical interface-Mechanical specifications for the network medium, such as cable specifications, the medium connector and pin-out details (the number and functions of the various pins in a network connector), or radio transceiver specifications. Signaling—The process of transmitting and receiving encoded data over the network medium, including modulation schemes and timing/synchronization.

What is Single Mode Fiber (SMF)?

Single Mode Fiber (SMF) has a small core (8 to 10 microns) and a long wavelength, near infrared (1310 nm or 1550 nm) light signal, generated by a laser. Single mode cables support data rates up to 100 Gbps and cable runs of many kilometers, depending on the quality of the cable and optics. There are two grades of SMF cable; OS1 is designed for indoor use, while OS2 is for outdoor deployment.

What is 1000BASE-LX specification?

Specification: 1000BASE-LX Optics: 1300 nm 1310 nm Cable: MMF (OM1/OM2/OM3) SMF (OS1/OS2) Maximum Distance: 550 m (1804 feet) 5 km (3.1 miles) Connectors:SC, LC

What is 100BASE-FX specification?

Specification: 100BASE-FX Optics: 1300 nm Cable: MMF (OM1), MMF (OM2) Maximum Distance: 2 km (1.2 miles) Connectors: ST, SC, MT-RJ

What is 100BASE-SX specification?

Specification: 100BASE-SX Optics: 850 nm Cable: MMF (OM1) ,MMF (OM2) Maximum Distance: 300 m (984 feet) Connectors: ST, SC, LC

What is 10GBASE-LR specification?

Specification: 10GBASE-LR Optics: 1310 nm Cable: SMF (OS1/OS2) Maximum Distance: 10 km (6.2 miles) Connectors: SC, LC

What is 10GBASE-SR specification?

Specification: 10GBASE-SR Optics: 850 nm Cable: MMF (OM1) | MMF (OM2) | MMF (OM3) | MMF (OM4) Maximum Distance: 33 m (108 feet) | 82 m (269 feet) | 300 m (984 feet) | 400 m (1312 feet) Connectors:SC, LC

What is 1000BASE-SX specification?

Specification: 850 nm Optics: 850 nm Cable: MMF (OM1)MMF |(OM2), MMF (OM3) Maximum Distance: 275 m (902 feet) | 550 m (1804 feet) Connectors: ST, SC, LC, MT-RJ

What is Straight Tip (ST) fiber optic cabling?

Straight Tip (ST) is an early bayonet-style connector that uses a push-and-twist locking mechanism. ST was used mostly for multimode networks, but it is not widely used for Ethernet installations anymore.

What are telecommunication rooms?

Telecommunications Room-Houses horizontal cross-connects. Essentially, this is a termination point for the horizontal cabling along with a connection to backbone cabling. An equipment room is similar to a telecommunications room but contains the main or intermediate cross-connects. Equipment rooms are also likely to house "complex" equipment, such as switches, routers, and modems.

What is Local Connector (LC) fiber optic cabling?

The Local Connector (LC) (also referred to as Lucent Connector) is a small-form-factor connector with a tabbed push/pull design. LC is similar to SC, but the smaller size allows for higher port density. LC is a widely adopted form factor for Gigabit Ethernet and 10/40 GbE.

What is subscriber connector (SC) fiber optic cabling?

The Subscriber Connector (SC) is a push/pull design, allowing for simple insertion and removal. It can be used for single- or multimode. It is commonly used for Gigabit Ethernet.

What are some physical layer devices?

Transceiver-The part of a network interface that sends and receives signals over the network media. Repeater-A device that amplifies an electronic signal to extend the maximum allowable distance for a media type. Hub-A multiport repeater, deployed as the central point of connection for nodes. Media converter-A device that converts one media signaling type to another. Modem-A device that performs some type of signal modulation and demodulation, such as sending digital data over an analog line.

What are nodes and links?

You can think of any network in terms of nodes and links. The nodes are devices that send, receive, and forward data and the links are the communications pathways between them.

What is the Internet Engineering Task Force (IETF)?

focuses on solutions to Internet problems and the adoption of new standards, published as Requests for Comments (RFCs). Some RFCs describe network services or protocols and their implementation, while others summarize policies. An older RFC is never updated. If changes are required, a new RFC is published with a new number. Not all RFCs describe standards. Some are designated informational, while others are experimental. The official repository for RFCs is at rfc-editor.org .

What is the Internet Assigned Numbers Authority (IANA)?

manages allocation of IP addresses and maintenance of the top-level domain space. IANA is currently run by Internet Corporation for Assigned Names and Numbers (ICANN). IANA allocates addresses to regional registries who then allocate them to local registries or ISPs.