MAN and WAN

What are SONET advantages?

1. Support synchronous time division multiplexing technique that is capable of sending data at 100Mbps. 2. The network topology is a ring 3. The ring is actually composed of multiple rings that enable the network to provide backup in the event of a segment failure (low failure rate)

How does a router decide which line to transmit on?

A router must select the one transmission line that will best provide a path to the destination and in an optimal manner Often many possible routes exist between sender and receiver

What is metro Ethernet?

A service in which the provider creates a door-to-door Ethernet connection between two locations.

What are typically connection-oriented?

Applications such as large file transfer and sensitive transactions such as banking and business

A network typically found in local area networks but occasionally found in wide area networks

Broadcast network

When serious congestion occurs what happens?

Buffers overflow and packets are lost

Whenever a node needs a routing decision, the ___ node is consulted.

Central

One routing table is kept at a central node.

Centralized routing

A sub-network in which a dedicated circuit is established between sender and receiver and all data passes over this ciruit

Circuit switched network

What are the types of Network structures?

Circuit-switched, packet-switched, Datagram packet-switched network, Virtual circuit packet switched network, and broadcast

Buffer preallocation

- Before one node send a series of n packet to another node, the sending node inquires in advance whether the receiving node has enough buffer space for the n packet. - Before making a connection, user requests how much bandwidth is needed, or if connection needs to be real-time - Network checks to see if it can satisfy user request

The routing method, or algorithm, chosen to move packets through a network should be:

- Optimal so the least cost an be found - Fair, so all packets are treated equally - Robust, in case link or node failures occur and the network has to reroute traffic - Not too Robust so that the chosen paths do not oscillate too quickly between troubled spots

What routing does not allow the routing tables to change?

Static

___ ___ is simpler but does not adapt to network congestion or failures.

Static routing

A device that interfaces a user to a metwork

Station

What are two main components of WANs?

Station and Node

a physical network is the underlying connection of nodes and telecommunication links

Sub-network (network cloud)

Example of Circuit switched network is

Telephone system

Example of Explicit congestion control:

The network often sends one or more signals to a transmitting station, informing the station to slow down or stop its insertion of packets in the network

What is the responsibility of the network cloud?

They type and number of interconnections between nodes and the way network data is passed from node to node

True/False: Routing Information Protocol is both adaptive and distributed.

True

DNS converts the ____ of the request into an ___ address and sends the request along.

URL;IP

What creates a logical path through the subnet and all packets from one connection follow this path

Virtual circuit packet switched network

The ___ is the entire system: the nodes, the stations, the communication lines, the software, and the users.

WAN

The communications network with its nodes and telecommunication links is essentially a

Weighted network graph

What is the problem with Datagram networks?

When a large group of packets is addressed to the same destination, the network's nodes must examine each packet individually and determine each packet's next path.

With ____ routing, routing tables can change to reflect changes in the network

adaptive

The frame relay router experiencing congestion sends a signal back to the originating station which then slows down its transmission. This is called ____

backward explicit congestion notification

Dynamically allocate more

bandwidth on demand

What requires both sender and receiver to create a connection before any data is transferred?

connection-oriented application

A network application can be either

connection-oriented or connetionless

A _____ _____ does not create a connection first but simply sends the data.

connectionless application

A metropolitan are network (MAN)

covers a city or a region of a city

A wide area network (WAN)

covers multiple cities, states, countries, and even the solar system (routes packets)

Adaptive routing is a

dynamic technique in which routing tables react to network fluctuations, such as congestion and node failure.

Ethernet MAns have Higher ____ ___.

failover time

In WAN, LAN type connection is not ___.

feasible

When a frame relay router experiences congestion, it sends a congestion signal forward to the destination station, which in turn tells the originating station to slow down the transfer of data. This is called ___

forward explicit congestion notification

MAns are design to have:

highly redundant circuits so that in the event of a component failure, the network can quickly reroute the traffic away from the failed component (low failover time).

LAN works as a __-____ network in that clusters of workstations are connected to a central point (hub or swicth) through which workstations can transmit messages to one another.

hub-based

Multiple LANs are ____

interconnected

MANs is a ring that is both ___ and ___

logically;physically

WANs usually follow a ___ topology, and requires ___ to transfer data across the network.

mesh;routing

One of the latest forms of the metropolitan area network is

metro Ethernet

MANs cover

much greater distances than LANs do.

The ___ ___ is the underlying physical component of a network.

network structure

A device that allows one or more stations to access the physical network and is a transfer point for passing information through a network

node

Incoming data arrives on

one port is restransmitted out through a second port

With a datagram, each ___ is on its own and may follow its own path

packet

Centralized routing is ___ used. Most WANs employ distributed routing.

rarely

Connection oriented network application provides what is called a

reliable service

MANs are very often a

ring topology not a star wired ring

To be transmitted across a mesh network:

the data has to be passed along a route from workstation to workstation

WAN can be categorized by

the way it transfers information from one end of the cloud to the other

In the internet a node is a

very fast and powerful router with multiple ports.

A ___ can correspond to the dollar cost of using the communications link between two nodes

weight

Disadvantages of SONET

well proven but complex, and fairly expensive

What is an example of connectionless application?

DNS

One form of packet switched network is the

Datagram

What finds all possible paths between two locations?

Dijkstra's least cost algorithm

In ___ routing each node maintains its own routing table.

Distributed

MANs can be provisioned

Dynamically

What can easily scalabel from 10 Mbps to 10 Gbps?

Ethernet MANs

The network can inform its applications that congestion has occurred and the applications can take action. This is called:

Explicit congestion control.

___ provides some guarantee that information traveling through the network will not be lost and that the information packets will be delivered to the intended receiver.

FTP

MANs have almost exclusively

Fiber Optic systems

Routing Information Protocol (RIP)

First routing protocol used on the internet

When a packet arrives at a node, the node sends a copy of the packet out every link except the link the packet arrived on. This is called

Flooding Routing

What does MANs support?

High-speed disaster recovery systems, real-time transaction backup systems, interconnections between corporate data centers and internet service providers, and government, business, medicine, and education high-speed interconnections.

metro Ethernet is found when two locations are connect to an

ISP

What is connection admission control

If users request can be satisfied, connection is established. If user does not need high bandwidth or real time, a simpler cheaper connection is created.

An application can observe its own traffic and notice if packets are disappearing. If so, there may be congestion. This is called:

Implicit congestion control

What can we do to reduce or eliminate network congestion?

Increasing the speed of the node processor and the amount of buffer space in the node

Where do MANs borrow technologies from?

LANs

___ ___ is a physical structure and connection between nodes and is the vehicle for getting the data from sender to destination.

Network cloud

When a network or a part of a network becomes so saturated with data packets that packet transfer is noticeably impeded, What occurs?

Network congestion

MANs can recover from from

Network faults very quickly

What are interconnected in a ring fashion?

Network routers and switches

What can cause network congestion?

Node and link failures; high amounts of traffic; improper network palnning

a network in which all data messages are transmitted using fixed-sized packages, called packets.

Packet switched network

What is used to drop the fail over time?

Rapid spanning tree protocol

Each node in a WAN is a ___ that accepts an input packet, examines the destination address, and forwards the packet on to a particular telecommunications line.

Router

What was a form of distance vector routing?

Routing Information Protocol

Ethernet MANs are less expensive then

SONET

MANs are based on one of two basic forms of supporting technology:

SONET or Ethernet