Network Chapter 8

Addressing Resolution Protocol (ATM ARP)

Maps Layer 3 network addresses such as Internet Protocol (IP) or Internet Packet Exchange (IPX) to the Laye 2 address. Offers reliable QoS.

Switching

Technique used for transmitting information over a network to the destination network device

Leased Data Line

Telecommunication path that is available 24 hours a day for use by a designated user: dedicated line and leased lines are essentially the same thing. Usually between 56 Kbps and 2 Mbpd.

ISDN Hardware

Terminals equipment (TE), terminal adapters (TAs), netowrk termination (NT) devices, line termination (LT), and exchange termination (ET) equipment. Network termination unit (NTU). NTU can directly connect to ISDN aware equipment

Circuitry Switching

One endpoint creates a dingle path connection to another, depending on the requirements. Connection path between end points. No guarantee that data will be transmitted through the same path.

Digital Signal Services (DS)

hierarchy of different digital signals that transfer data at different rates. T-carrier system is the most common physical implementation of the American National Standards Institute (ANSI) Digital Signal Hierarchy (DSH) specifications. DSH is a channelized data transmission standard used to multiplex several single data or voice channels for a greater total bandwidth.

ISDN

is a digital circuit switching technology that carries both voice and data over digital phone lines or PSTN wires. Uses digital channels to carry the payload and manage the call. Channels re the "B" (bearer) channel has a bandwidth of 64 kb. and the "D" (delta) channel has a 16 kb ir 64 kb, depending on the type of service.

Fixed cell size

The fixed 53-byte cell size enables ATM to be implemented in hardware, reducing overhead and drain on resources required to move data on a network

Advantages of Frame Relay

*It offers facilities like that of a leased line, but at a significantly lower cost *It delivers increased performance with reduced network complexity *It can be implemented over the existing technology *It can be easily configured to combine traffic from different networking protocols *It offers a pay-as-you-go structure *It can carry traffic that is not IP traffic

MPLS Multiprotocol Label Switching benefits

1) Virtual Private Networking (VPN) 2) Traffic engineering (TE) 3) Quality of Service (QoS) 4) Any prawn sport over MPLS (AToM)

WAN- Wide Access Network

A netowrk that spans a large area, often across myltiple geographical locations. Connect multilpe LANs and other network by using long-range transmission media.

Local Collector ring

A local collector ring interfaces with users and comprises digital cross-connect switches (DCSs) at the user's location or connects to the user's location by a T-carrier. The DCS acts as a concentrator to transmit signals from a user to the SONET ring. It supports connections from different technologies and from multiple users. The technologies taht can connect to the ring include ATM, T1 or T3 lines; ISDN; or DSL voice.

NNI

A switch that is inside an ATM network. Can connect to an ATM network but is rare.

UNI

A user device, is an ATM border device that connects one ATM network to another ATM network or a LAN,

ISDN Terminal Adapter (Integrated Services for Digital Netwrork

Adapter is similar to a modem in that it joins Basic Rate Interface. Connection to different physical interfaces on a router. Does not convert between Convert between analog and diagonal singling

Types of traffic

Allows the capability to carry data, voice and video simultaneously on the same channel.

WAN Devices

An able you to connect LANs together.

BISDN Broadband Integrated Services Digital Network

Anticipated standard for the emerging information superhighway.

Dial-up lines

Are local loop public switched telephone eye them (PSTN) connection that use modems, existing phone lines, and long-distance carrier services to provide low-cost, low-bandwidth WAN connectivity, and remote network access. PSTN is also know as the plain old telephone system (POTS)

Broadband DSL

Broadband DSL offers high-speed Internet access with much higher speeds then dial-up connections. Telephone companies use DSL to offer data, video, and voice services over exiting phone lines.

Broadband Cable

Broadband cable offers high-speed Internet access with higher speeds then dial-up connections and broadband DSL. It also allows the simultaneous use of a telephone line,

QoS

Built-in QoS features in the design aid in the flow of data between endpoint so of the ATM network

Cable Internet Access

Cable television connection and a cable modem to provide high-speed Internet access to homes and small business,

CSU/DSU

Cancel Service Unit/Data Service Unit is a combination of two WAN connectivity devices that work together to connect a digital WAN line with a customer's LAN. DSU receives the signal from the LAN and passes to the CSU. CSU converts the signal format to make it compatible with the Digital Data Servie (DDS( on the WAN line.

PPPoE (Point-to-Point over Ethernet)

Carry data on top of the ATM infrastructure. Used to provision DSL services for customers.

DSH defines a Hierarchy of DSx

DS0: Carries data at the rate of 64 Kbps DS1: Carries data at the rate of 1.5 Mbps DS2: Carries data at the rate of 6.3 Mbps DS3: Carries data at the rate of 44.4 Mbps DS4: Carries data at the rate of 274.2 Mbps

Packet Switching networks

Data to be transmitted is broken into small units known as packets that move in sequence through the network. Each packet takes the best route available at any given time. Each data contains all of the routing and sequence information

Disadvantages of Frame Relay

Data transmission may exceed network capacity as clients use a common network and this results in the slowing down of the network *The "burst" nature of traffic in a frame relay cloud, along with the use of variable-length frames, makes it difficult to provide QoS. During its most popular years in the 1990s, it was considered unsuitable for real-time traffic suck as voice or video.

ATM Features

Description

SAL Technology

Description

Virtual Circuit Type

Description

Modem

Enable digital data to be sent over an analog medium cinch as a telephone wire or cable provider's line. Digital signals are converted into an analog format suitable for transmission through analog carries and then restored to digital format on the receiving end. The three main types of modems that you will encounter are:

MPLS Multiprotocol Label Switching

High-performance multi-service switching technology that is used in packet data networks. Defined by a set of Internet Engineering Task Force (IETF) specification that enable Layer 3 devices such as routers to establish and manage network traffic. Ensures faster switching of data as it follows label switching that helps save processing time of packets by the label-switching routers. Packet-forwarding technology that uses labels to are its forwarding decisions.

Dial-Up Connections

PSTN (Public Switch Telephone Newtwork) connections that use modems, existing phone lines, existing phone loonies, and long-distance carrier services to provide low-cost, low-bandwidth WAN connectivity and remote network access.

Digital Network Hierarchies.

Plesiochronous Digital hierarchy (PDH) and the Synchronous Digital Hierarchy (SDH), Data over optic or microwave radio systems.

Broadband backbone network

the broadband backbone network routes data between regional networks. It is capable of carrying a large amoun of data simultaneously in the ring, and the requester picks the data as it is transmitted.

ISDN comes in two types of service.

1) Basic Rate Interface (BRI): 2 B channels + one 16 kb D channel for 128 kn throughput 2) Primary Rate Interface (PRI): 23 B channels + one 64 kb D channel for (near) T1 throughput.

T Carrier Level Zero (Channel Data Rate) First Level Intermediate Level, T-carrier only Second Level Third Level Fourth Level Fifth Level

64 Kbps 1.544 Mbps (DS1, 24 Ch, T1) 3.152 Mbps (DS1C, 48 Ch.) 6.312 Mbps (DS2, 96 Ch. T2) 44.736 Mbps (DS3, 672 Ch. T3) 274.176 Mbps (DS4, 4032 Ch) 400.352 Mbps (DS5, 5760 Ch)

E Carrier Level Zero (Channel Data Rate) First Level Intermediate Level, T-carrier only Second Level Third Level Fourth Level Fifth Level

64 Kbps 2.048 Mbps (E1, 32 Ch) - 8.448 Mbps (E2, 128 Ch) 34.368 Mbps (E3, 512 Ch) 139.264 Mbps (E4, 2048 Ch) 565.148 Mbps (E5, 8192 Ch)

Very High-Bit-Rate DSL

Asymmetric solution that provides extremely fast connections over short distance on standard copper phone wiring. Offers speeds up to 52 Mbps.

ATM Asynchronous Transfer Mode

Cell-switching network technology that supports high-speed transfer of voice, video and data in LANs, WAN, and telephone networks. LAN to WAN connectivity seamless. Versatility and high bandwidth availability. Transferred in fixed-size packets, called cells, consisting of 53 bytes. ATM networks are make up of switches. Transport data cells among networks. Provides connection-oriented, end-to-end QoS. Can guarantee QoS for a particular virtual channel because all switches along a path agree upon the bandwidth before the connection is established. Uses a Layer 2 addressing scheme.

High-bit-rate DSL

Downloads speeds tend to be significantly faster than upload speeds. Receives and sends data at the same seed. Requires two lines that are separate from the normal phone lines. Transfer rates of 1.54 Mbps, which are comparable to a T1 line.

Virtual Circuit Switching

Is a switching technique to transfer packer on logical circuits that do not have physical resources, such as frequencies or time slots allocatesd.

ISDN works at

Layer 1, 2 and 3 of the OSI model. AT Layer 1, the frames are 48 bits long and differ in structure depending on the direction of the traffic. At layer 2 the connection is blanced, meaning there is no master/slave relationship where the master (DCE) set the clock rate and slave (DTE) must adhere to the DCE's speed. Both the DCE and DTE and treated equally by the protocol. At layer 3, end-to-end connections are created for user-to-user, circuit-switch or packet-switch functionalily similar to X.25.ISDN has largely been replaced by DSL.

Satellite media

Long-range global WAN transmission. Physical link transfers the signal to a satellite link at some point for transmission for data delivery.

Asymmetric DSL

Most popular DSL technology, Residential customers to access the Internet and receive phone calls simultaneously. High bandwidth, high-speed transmission over regular telephone lines. Offers speeds of up to 8 Mbps

WAN switch

Multi port inter networking device that normally switches traffic and operates at the DATA Link layer (Layer 2) or the OSI model. Share bandwidth among allocated service priorities, recover fro outages and provide network designe and management systems.

Real-time and non-real-time data support

Real-time data support is used for time-sensitive data such as voice or video and travels at a higher priority then non-real-time data.

PErmanent

PVCs are usually associated with leased lines. They connect two end points and are always on, why they are referred to as permanent. PVC is established, it is manually built and maintained by a telephone company (telco). Telco identifies the endpoint so with a data link connection identifier (DLCI). PVCs provide a fast, reliable connection between endpoint so because the connection is always on. Customer pays a fixed monthly fee per connection.

WAN Topology Point-to-Multipoint

Physical Star, which a central site is the hubs, multiple branch sites are spokes. Behaves like a hub. All nodes belong to the same subnet. If often used in frame relay networks.

DSL Digital Subscriber line

Point-to-point public network access broadband Interbet connections method that transmits digital signals over existing phone lines. DSL accomplished this connection by transporting voice as low-frequency signals and data as high-frequencies signals. Operates on Layer 1 and 2 of the OSI model.

Bandwidth options

Provides a wide range of high-bandwidth options. Although it has no inherent bandwidth limitation, typical ATM implementations can support from 51.84 Mbps to 2488 Gbps, with 155 Mbps to 622 Mbps being the most common. Interface capable of 160 Gbps.

Symmetric DSL

Provides symmetric connectivity to user. Also uses telephone lines. Guarantees of frame realtor the higher performance of a leased line.

Switch

SVCs are acclimated with dial-up connections. SVCs provide more flexibility than PVCs and allow a single connection to an endpoint to be connected to multiple endpoint so as needed. When a network device attempts to connect to a WAM, an SVC is requested and the carrier establishes the connection. Customers typically pay by sonnet ion time and the monthly charge is less than that of a VPC. SVCs are useful when you need a part-time connection.

Access Server

Server manages dial-in and dial-out user communications. Mixture of analog and digital interfaces and support hundreds of simultaneous users. Access servers function as control points for roaming and remote users so that they can access internal resources from external locations.

Cell Switching Networks

Similar to packet switching networks, except that data is transmitted as fixed-length Cael's instead of in variable-length packets. Not fill up an entire cell. Remainder of the space is filled with blank or filler data until the cell reaches its fixed size.

Point-to-Point connection

Simple WAN topology that provides a direct connection between two nodes, is a type of bus, with only two nodes on it. With a /30 subnet mask. Dedicated leased lines and dial-up connections.

Labels

Special headers that are 4 bytes long, I server between the Layer 2 and Layer 3 headers of the packets. Router that has MPLS enabled on its interface is referred to as a label switching router (LSR)

Frame Relay Caracteristics

Speeds can rang e from 56 Kbps to 1.544 with the lower speeds, such as 56, 64, 128, 384. And 512 Knps. Concept of a committed information rate (CIR), which is the minimum bandwidth that a customer's virtual circuit is guaranteed to have

Frame Relay

WAN protocol that functions at the Physical and DAta Link layers (Layer 1 and 2) of the OSI model. Transmission of data to over a shared network medium and bandwidth using virtual circuits.

X.25 Switch Networks

The first widely implemented packet-switching network technology. Developed in the 1970s. Functionality corresponds to Layers 1, 2, and 3 of the OSI model. Was designed t move data across the less-than-reliable analog long-distance public carrier lines of the time.

Traffic contracting and shaping

Traffic contracting assigns a set data rate to an endpoint. When an endpoint connects to an ATM network, it enters into a contract with the network for service quality. The ATM network will not contact more services than it can provide. Traffic shaping optimizes data flow on an ATM network. It includes control of bursts and optimizing bandwidth allocation,

ATM Network Interface Types

UNI- User-to-Network Interface NNI- Network-to-Network Interface

Regional Network

a regional network combines multiple collector rings by using add/drop multiplexers (ADMs). The ADM allows data from collector rings to be added tot he regional ring. The data that is not accepted by the service requester is discarded or sent back to the ADM.

T-Carrier Systems

is a digital and packet-switch system designed to carry multiplexed telephone connections. Communications more scalable then analog, circuit-switch systems, T carriers systems use two twisted pairs of copper wires. T1 and T3 are the two most common t-services leverl. E-1 and E-3 are European leased lines.

Metro-Ethernet

is a metropolitan area network (MAN) that uses Ethernet standards. Can connect LANs and individual users to a WAN or to the Internet. Organizations in large cities can use Metro-Ethernet to connect branch location or offices to an intranet. Star network or mesh network topology with servers or routers interconnected through cable or fiber optic media. Operates at Layer 2 of the OSI model. Synchronous Optical Networking (SONET), MPLS or a combination of IP-related protocols. Using 802.1q VLAN tagging over Metro-Ethernet.

SONET/SDH-Synchronous Digital Hierarchy

is a standard for synchronous data transport over a fiber optic cable. Published by ANSI. Has two specifications: Optical Carrier (OC) specifications for fiber optic cabling and the Secure Transfer Specification (STS) for copper wire. SONET over copper has server limitations. Deployed in a self-healing dual-fiber ring topology. Fiber Distributed Data Interface (FDDI). Is widely used inside service providers to act as a high-speed backbone for other systems, suck as frame relay, ATM and Metro-Ethernet. Operates at Layer 1 of the OSI model. Used on a ATM network, and connections to the lines can be made by using single-mode or multi-mode optical fiber. Divided into three areas. Each area controlled byu an integrated management system.