Overview of RARP, BOOTP, DHCP and PXE protocols for dynamic IP address assignment.
Dynamic IP address assignment to a host (or interface) is a common problem in TCP/IP based networks.
Manual and static assignment of IP addresses does not scale well and becomes a labor intensive task with a growing number of hosts.
An early approach for dynamic IP address assignment was RARP (Reverse ARP) which ran directly on the Ethernet protocol layer.
The many problems of RARP such as the inability to be routed between subnets were solved with BOOTP (Bootstrap Protocol).
BOOTP, however, ended to have its own set of limitations like lack of a lease time for IP addresses.
DHCP (Dynamic Host Configuration Protocol) was therefore defined as an extension to BOOTP.
DHCP is backward compatible with BOOTP thus allowing some degree of interoperability between the 2 protocols.
The state-of-the-art protocol for dynamic IP address assignment is, however, is DHCP.
DHCPv6 is an adaption of DHCP for IPv6 based networks.
Overview of RARP, BOOTP, DHCP and PXE protocols for dynamic IP address assignment.
Dynamic IP address assignment to a host (or interface) is a common problem in TCP/IP based networks.
Manual and static assignment of IP addresses does not scale well and becomes a labor intensive task with a growing number of hosts.
An early approach for dynamic IP address assignment was RARP (Reverse ARP) which ran directly on the Ethernet protocol layer.
The many problems of RARP such as the inability to be routed between subnets were solved with BOOTP (Bootstrap Protocol).
BOOTP, however, ended to have its own set of limitations like lack of a lease time for IP addresses.
DHCP (Dynamic Host Configuration Protocol) was therefore defined as an extension to BOOTP.
DHCP is backward compatible with BOOTP thus allowing some degree of interoperability between the 2 protocols.
The state-of-the-art protocol for dynamic IP address assignment is, however, is DHCP.
DHCPv6 is an adaption of DHCP for IPv6 based networks.
Lecture slides from the 3rd-year module on Computer Networks at the University of Birmingham, UK.
This presentation covers the Data-Link layer of the networks stack, primarily Error Control, Flow Control and Framing.
Illustration 2
Assume that the direct material inventory of Saron Furniture Factory amounts to Br. 248,000 at the beginning of the year i.e., as of July 1, 2014. Purchases of direct materials amounting Br. 440,000 was made and freight cost of Br. 3,200 is incurred during the year, and the amount of direct materials inventory at the end of the year is Br. 234,900.
Compute the direct materials used
Assume further that Saron Furniture Factory has beginning work in process of Br. 220,000 and ending work in process of Br. 263,200. The direct labor cost incurred in the year is Br. 875,000 and the different manufacturing overhead costs incurred during the year are given below:
Indirect labor
Br. 98, 600
Depreciation on factory equipment
44,600
Light and power
43,600
Depreciation of factory building
12,000
Insurance expense on factory properties
9,500
Property tax
19,500
Factory supplies
9,900
Total Manufacturing overhead cost
Br. 237, 700
Compute the cost of goods manufactured.
Assume also that the finished goods inventory at the beginning of the year was Br. 314,000 and the ending inventory of finished goods is Br. 364,000 for Saron Furniture Factory.
Compute the cost of goods sold
Illustration 2
Assume that the direct material inventory of Saron Furniture Factory amounts to Br. 248,000 at the beginning of the year i.e., as of July 1, 2014. Purchases of direct materials amounting Br. 440,000 was made and freight cost of Br. 3,200 is incurred during the year, and the amount of direct materials inventory at the end of the year is Br. 234,900.
Compute the direct materials used
Assume further that Saron Furniture Factory has beginning work in process of Br. 220,000 and ending work in process of Br. 263,200. The direct labor cost incurred in the year is Br. 875,000 and the different manufacturing overhead costs incurred during the year are given below:
Indirect labor
Br. 98, 600
Depreciation on factory equipment
44,600
Light and power
43,600
Depreciation of factory building
12,000
Insurance expense on factory properties
9,500
Property tax
19,500
Factory supplies
9,900
Total Manufacturing overhead cost
Br. 237, 700
Compute the cost of goods manufactured.
Assume also that the finished goods inventory at the beginning of the year was Br. 314,000 and the ending inventory of finished goods is Br. 364,000 for Saron Furniture Factory.
Compute the cost of goods sold
Illustration 2
Assume that the direct material inventory of Saron Furniture Factory amounts to Br. 248,000 at the beginning of the year i.e., as of July 1, 2014. Purchases of direct materials amounting Br. 440,000 was made and freight cost of Br. 3,200 is incurred during the year, and the amount of direct materials inventory at the end of the year is Br. 234,900.
Compute the direct materials used
Assume further that Saron Furniture Factory has beginning work in process of Br. 220,000 and e
Lecture slides from the 3rd-year module on Computer Networks at the University of Birmingham, UK.
This presentation covers the Data-Link layer of the networks stack, primarily Error Control, Flow Control and Framing.
Illustration 2
Assume that the direct material inventory of Saron Furniture Factory amounts to Br. 248,000 at the beginning of the year i.e., as of July 1, 2014. Purchases of direct materials amounting Br. 440,000 was made and freight cost of Br. 3,200 is incurred during the year, and the amount of direct materials inventory at the end of the year is Br. 234,900.
Compute the direct materials used
Assume further that Saron Furniture Factory has beginning work in process of Br. 220,000 and ending work in process of Br. 263,200. The direct labor cost incurred in the year is Br. 875,000 and the different manufacturing overhead costs incurred during the year are given below:
Indirect labor
Br. 98, 600
Depreciation on factory equipment
44,600
Light and power
43,600
Depreciation of factory building
12,000
Insurance expense on factory properties
9,500
Property tax
19,500
Factory supplies
9,900
Total Manufacturing overhead cost
Br. 237, 700
Compute the cost of goods manufactured.
Assume also that the finished goods inventory at the beginning of the year was Br. 314,000 and the ending inventory of finished goods is Br. 364,000 for Saron Furniture Factory.
Compute the cost of goods sold
Illustration 2
Assume that the direct material inventory of Saron Furniture Factory amounts to Br. 248,000 at the beginning of the year i.e., as of July 1, 2014. Purchases of direct materials amounting Br. 440,000 was made and freight cost of Br. 3,200 is incurred during the year, and the amount of direct materials inventory at the end of the year is Br. 234,900.
Compute the direct materials used
Assume further that Saron Furniture Factory has beginning work in process of Br. 220,000 and ending work in process of Br. 263,200. The direct labor cost incurred in the year is Br. 875,000 and the different manufacturing overhead costs incurred during the year are given below:
Indirect labor
Br. 98, 600
Depreciation on factory equipment
44,600
Light and power
43,600
Depreciation of factory building
12,000
Insurance expense on factory properties
9,500
Property tax
19,500
Factory supplies
9,900
Total Manufacturing overhead cost
Br. 237, 700
Compute the cost of goods manufactured.
Assume also that the finished goods inventory at the beginning of the year was Br. 314,000 and the ending inventory of finished goods is Br. 364,000 for Saron Furniture Factory.
Compute the cost of goods sold
Illustration 2
Assume that the direct material inventory of Saron Furniture Factory amounts to Br. 248,000 at the beginning of the year i.e., as of July 1, 2014. Purchases of direct materials amounting Br. 440,000 was made and freight cost of Br. 3,200 is incurred during the year, and the amount of direct materials inventory at the end of the year is Br. 234,900.
Compute the direct materials used
Assume further that Saron Furniture Factory has beginning work in process of Br. 220,000 and e
Introduction, Virtual and Datagram networks, study of router, IP protocol and addressing in the Internet, Routing algorithms, Broadcast and Multicast routing
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Mission to Decommission: Importance of Decommissioning Products to Increase E...
Switch networking
1. Unit-IV
Network Switching Techniques: Circuit, Message,
Packet and Hybrid Switching Techniques.X.25, ISDN.
Logical Addressing, Ipv4, Ipv6, Address Mapping, ARP,
RARP, BOOTP and DHCP, User Datagram Protocol,
Transmission Control Protocol, SCTP.
Click to add text
2. Introduction
• A network is a set of connected devices.
• Whenever we have multiple devices, we have the problem of how
to connect them to make one-to-one communication possible.
• One solution is to make a point-to-point connection between each
pair of devices (a mesh topology) or between a central device and
every other device (a star topology).
• These methods, however, are impractical and wasteful when
applied to very large networks.
• The number and length of the links require too much
infrastructure to be cost-efficient, and the majority of those links
would be idle most of the time.
• A better solution is switching.
3. Switching
• A switched network consists of a series of interlinked nodes,
called switches.
• Switches are devices capable of creating temporary
connections between two or more devices linked to the switch.
• In a switched network, some of these nodes are connected to
the end systems (computers or telephones). Others are used
only for routing.
• Figure shows a switched network.
4. Switched Network
The end systems (communicating devices) are labeled A, B, C, D, and so on, and the
switches are labeled I, II, III, IV, and V.}
5. Key Points
• Switching is the generic method for establishing a path for
point-to-point.
• It involves the nodes in the network utilizing their direct
communication lines to other nodes.
• Each node has the capability to switch to a neighboring node.
• One of the most important functions of the network layer is to
employ the switching capability of the nodes in order to route
messages across the network.
• There are three basic methods of switching: circuit switching,
packet switching and message switching.
7. CIRCUIT-SWITCHED NETWORKS
• A circuit-switched network consists of a set of switches
connected by physical links.
• A connection between two stations is a dedicated path made of
one or more links. However, each connection uses only one
dedicated channel on each link. Each link is normally divided
into n channels by using FDM or TDM.
• Circuit switching takes place at the physical layer.
• Before starting communication, the stations must make a
reservation for the resources to be used during the
communication. These resources, such as channels, switch
buffers, switch processing time, and switch input/output ports,
must remain dedicated during the entire duration of data
transfer until the teardown phase.
9. Example
• Let us use a circuit-switched network to connect eight
telephones in a small area. Communication is through 4-kHz
voice channels. We assume that each link uses FDM to
connect a maximum of two voice channels. The bandwidth of
each link is then 8 kHz. Figure shows the situation.
• Telephone 1 is connected to telephone 7; 2 to 5; 3 to 8; and 4
to 6. Of course the situation may change when new
connections are made. The switch controls the connections.
11. Communication Process Steps
• Setup Phase: Before the two parties (or multiple parties in a
conference call) can communicate , a dedicated circuit
(combination of channels in links) needs to be established. The
end systems are normally connected through dedicated lines
to the switches, so connection setup means creating dedicated
channels between the switches.
• Data Transfer Phase: After the establishment of the dedicated
circuit (channels), the two parties can transfer data.
• Teardown Phase: When one of the parties needs to disconnect,
a signal is sent to each switch to release the resources.
12. Advantages of Circuit Switching
• The main advantage of circuit switching is that a committed
transmission channel is established between the computers
which gives a guaranteed data rate.
• In circuit switching there is no delay in data flow because of
the dedicated transmission path.
13. Disadvantages of Circuit Switching
• It takes long time to establish connection.
• More bandwidth is required in setting up of dedicated
channels.
• It cannot be used to transmit any other data even if the channel
is free as the connection is dedicated in circuit switching.
14. Packet Switching
• In data communications, we need to send messages from one
end system to another. If the message is going to pass through
a packet-switched network, it needs to be divided into packets
of fixed or variable size.
• The size of the packet is determined by the network and the
governing protocol
• In a packet-switched network, there is no resource reservation;
resources are allocated on demand.
15. Advantage of Packet Switching over
Circuit Switching
• More efficient in terms of bandwidth, since the concept of
reserving circuit is not there.
• Minimal transmission latency.
• More reliable as destination can detect the missing packet.
• More fault tolerant because packets may follow different path
in case any link is down, Unlike Circuit Switching.
• Cost effective and comparatively cheaper to implement.
16. Disadvantage of Packet Switching
over Circuit Switching
• Packet Switching don’t give packets in order, whereas Circuit
Switching provides ordered delivery of packets because all the
packets follow the same path.
• Since the packets are unordered, we need to provide sequence
numbers to each packet.
• Complexity is more at each node because of the facility to
follow multiple path.
• Transmission delay is more because of rerouting.
• Packet Switching is beneficial only for small messages, but for
bursty data (large messages) Circuit Switching is better.
Click to add text
18. DATAGRAM NETWORKS
• In data communications, we need to send messages from one
end system to another.
• In a datagram network, each packet is treated independently of
all others. Even if a packet is part of a multipacket
transmission, the network treats it as though it existed alone.
• Packets in this approach are referred to as datagram's.
• Datagram switching is normally done at the network layer.
• The switches in a datagram network are traditionally referred
to as routers.
19. Example
•In this example, all four packets (or datagrams) belong to the same message, but may
travel different paths to reach their destination.
•This is so because the links may be involved in carrying packets from other sources and
do not have the necessary bandwidth available to carry all the packets from A to X.
•The datagram networks are sometimes referred to as connectionless networks. The term
connectionless here means that the switch (packet switch) does not keep information
about the connection state.
•There are no setup or teardown phases. Each packet is treated the same by a switch
regardless of its source or destination.
20. VIRTUAL-CIRCUIT NETWORKS
• A virtual-circuit network is a cross between a circuit-switched
network and a datagram network.
• It has some characteristics of both:
1. As in a circuit-switched network, there are setup and teardown
phases in addition to the data transfer phase.
2. Resources can be allocated during the setup phase, as in a
circuit-switched network, or on demand, as in a datagram
network.
3. As in a circuit-switched network, all packets follow the same
path established during the connection.
4. A virtual-circuit network is normally implemented in the data
link layer, while a circuit-switched network is implemented in
the physical layer and a datagram network in the network
layer.
21. Message Switching
• Message switching was a technique developed as an alternate
to circuit switching, before packet switching was introduced.
• In message switching, end users communicate by sending and
receiving messages that included the entire data to be shared.
• Messages are the smallest individual unit.
• The sender and receiver are not directly connected. There are a
number of intermediate nodes transfer data and ensure that the
message reaches its destination.
• Message switched data networks are hence called hop-by-hop
systems.
22. Message Switching Characteristics
• They provide 2 distinct and important characteristics:
1. Store and forward – The intermediate nodes have the
responsibility of transferring the entire message to the next
node. Hence, each node must have storage capacity. A
message will only be delivered if the next hop and the link
connecting it are both available, otherwise it’ll be stored
indefinitely. A store-and-forward switch forwards a message
only if sufficient resources are available and the next hop is
accepting data. This is called the store-and-forward property.
2. Message delivery – This implies wrapping the entire
information in a single message and transferring it from the
source to the destination node. Each message must have a
header that contains the message routing information,
including the source and destination.
23. Message Switched Network
• Message switching network consists of transmission links
(channels), store-and-forward switch nodes and end stations as
shown in the following figure:
24. Advantages of Message Switching
• As message switching is able to store the message for which
communication channel is not available, it helps in reducing
the traffic congestion in network.
• In message switching, the data channels are shared by the
network devices.
• It makes the traffic management efficient by assigning
priorities to the messages.
25. Disadvantages of Message Switching
• Message switching cannot be used for real time applications as
storing of messages causes delay.
• In message switching, message has to be stored for which
every intermediate devices in the network requires a large
storing capacity.
26. X.25
• X.25 is a protocol suite defined by ITU-T for packet switched
communications over WAN (Wide Area Network).
• It was originally designed for use in the 1970s and became
very popular in 1980s.
• Presently, it is used for networks for ATMs and credit card
verification.
• It allows multiple logical channels to use the same physical
line. It also permits data exchange between terminals with
different communication speeds.
27. X.25 has three protocol layers
• Physical Layer: It lays out the physical, electrical and
functional characteristics that interface between the computer
terminal and the link to the packet switched node. X.21
physical implementer is commonly used for the linking.
• Data Link Layer: It comprises the link access procedures for
exchanging data over the link. Here, control information for
transmission over the link is attached to the packets from the
packet layer to form the LAPB frame (Link Access Procedure
Balanced). This service ensures a bit-oriented, error-free, and
ordered delivery of frames.
28. X.25 has three protocol layers
• Packet Layer: This layer defines the format of data packets
and the procedures for control and transmission of the data
packets.
• It provides external virtual circuit service. Virtual circuits may
be of two types: virtual call and permanent virtual circuit.
• The virtual call is established dynamically when needed
through call set up procedure, and the circuit is relinquished
through call clearing procedure.
• Permanent virtual circuit, on the other hand, is fixed and
network assigned.
29.
30. ISDN: (Integrated Services Digital Network)
• These are a set of communication standards for simultaneous digital
transmission of voice, video, data, and other network services over
the public switched telephone network.
• The main feature of ISDN is that it can integrate speech and data on
the same lines, which were not available in the classic telephone
system.
• ISDN is a circuit-switched telephone network system but it also
provides access to packet switched networks that allows digital
transmission of voice and data.
• This results in potentially better voice or data quality than an analog
phone can provide.
• It provides a packet-switched connection for data in increments of
64 Kbit/s. It provided a maximum of 128 Kbit/s bandwidth in both
upstream and downstream directions..
• The ISDN works based on the standards defined by ITU-T (formerly
CCITT). The Telecommunication Standardization Sector (ITU-T)
coordinates standards for telecommunications on behalf of the
International Telecommunication Union (ITU) and is based in
Geneva, Switzerland.
31. Principles of ISDN
The various principles of ISDN as per ITU-T recommendation
are:
• To support switched and non-switched applications
• To support voice and non-voice applications
• Intelligence in the network
• Layered protocol architecture
• Variety of configurations
33. ISDN Services
ISDN provides a fully integrated digital service to users. These
services fall into 3 categories- bearer services, teleservices and
supplementary services.
Bearer Services:
• Transfer of information (voice, data and video) between users
without the network manipulating the content of that information is
provided by the bearer network.
• There is no need for the network to process the information and
therefore does not change the content.
• Bearer services belong to the first three layers of the OSI model.
They are well defined in the ISDN standard.
• They can be provided using circuit-switched, packet-switched ,etc
34. ISDN Services
Teleservices:
• In this the network may change or process the contents of the data.
• These services corresponds to layers 4-7 of the OSI model.
• Teleservices relay on the facilities of the bearer services and are
designed to accommodate complex user needs.
• The user need not to be aware of the details of the process.
• Teleservices include telephony, teletex, telefax, videotex and
teleconferencing.
Supplementary Service:
• Additional functionality to the bearer services and teleservices are
provided by supplementary services.
• Reverse charging, call waiting, and message handling are
examples of supplementary services which are all familiar with
today’s telephone company services.
35. Addressing
Four levels of addresses are used in an internet employing the
TCP/IP protocols:
• Physical (link) addresses,
• Logical (IP) addresses
• Port addresses
• Specific addresses
36.
37. Physical Addresses
• The physical address, also known as the link address, is the
address of a node as defined by its LAN or WAN. It is
included in the frame used by the data link layer. It is the
lowest-level address.
• The size and format of these addresses vary depending on the
network.
• For example, Ethernet uses a 6-byte (48-bit) physical address
that is imprinted on the network interface card (NIC).
38. Logical Addresses
• Logical addresses are necessary for universal communications
that are independent of underlying physical networks.
• A logical address in the Internet is currently a 32-bit address
that can uniquely define a host connected to the Internet.
39. Port Addresses
• The IP address and the physical address are necessary for a
quantity of data to travel from a source to the destination host.
• arrival at the destination host is not the final objective of data
communications .
• computers are devices that can run multiple processes at the
same time. For example, computer A can communicate with
computer C by using TELNET. At the same time, computer A
communicates with computer B by using the File Transfer
Protocol (FTP). For these processes to receive data
simultaneously, we need a method to label the different
processes.
• In the TCP/IP architecture, the label assigned to a process is
called a port address.
• A port address in TCP/IP is 16 bits in length.
40. Specific Addresses
• Some applications have user-friendly addresses that are
designed for that specific address.
• Examples include the e-mail address (for example,
forouzan@fhda.edu) and the Universal Resource Locator
(URL).
41. Logical Addresses
• we use the term IP address to mean a logical address in the
network layer of the TCP/IP protocol suite.
• The Internet addresses are 32 bits in length; this gives us a
maximum of 232 (4,294,967,296 (more than 4 billion))
addresses.
• These addresses are referred to as IPv4 (IP version 4)
addresses or simply IP addresses .
42. IPv4 ADDRESSES
• An IPv4 address is a 32-bit address.
• IPv4 addresses are unique(Two devices on the Internet can
never have the same address at the same time) and universal.
Notations:-
There are two prevalent notations to show an IPv4 address:
• binary notation
• dotted decimal notation.
43. Binary Notation
• In binary notation, the IPv4 address is displayed as 32 bits.
• Each octet is often referred to as a byte. So it is common to
hear an IPv4 address referred to as a 32-bit address or a 4-byte
address.
• The following is an example of an IPv4 address in binary
notation:
01110101 10010101 00011101 00000010
44. Dotted-Decimal Notation
• To make the IPv4 address more compact and easier to read,
Internet addresses are usually written in decimal form with a
decimal point (dot) separating the bytes.
45. Example
• Change the following IPv4 addresses from binary notation to
dotted-decimal notation.
a. 10000001 00001011 00001011 11101111
b. 11000001 10000011 00011011 11111111
46. Solution
• We replace each group of 8 bits with its equivalent decimal
number and add dots for separation.
a. 129.11.11.239
b. 193.131.27.255
47. Example
• Change the following IPv4 addresses from dotted-decimal
notation to binary notation.
a. 111.56.45.78
b. 221.34.7.82
48. Solution
• We replace each decimal number with its binary equivalent.
a. 01101111 00111000 00101101 01001110
b. 11011101 00100010 00000111 01010010
49. Classful Addressing
• IPv4 addressing, used the concept of classes.
• In classful addressing, the address space is divided into five
classes: A, B, C, D and E.
• Each class occupies some part of the address space.
50. Example
• Find the class of each address.
a. 00000001 00001011 00001011 11101111
b. 11000001 10000011 00011011 11111111
c. 14.23.120.8
d. 252.5.15.111
51. Solution
a. The first bit is 0. This is a class A address.
b. The first 2 bits are 1; the third bit is 0. This is a class C address.
c. The first byte is 14 (between 0 and 127); the class is A.
d. The first byte is 252 (between 240 and 255); the class is E.
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52. Classes and Blocks
• One problem with classful addressing is that each class is
divided into a fixed number of blocks with each block having a
fixed size as shown in Table.
In c1assfnl addressing, a large part of the available addresses
were wasted.
53.
54. Netid and Hostid
• In classful addressing, an IP address in class A, B, or C is
divided into netid and hostid.
• These parts are of varying lengths, depending on the class of
the address.
• Figure shows some netid and hostid bytes.
• Note that the concept does not apply to classes D and E.
• In class A, one byte defines the netid and three bytes define the
hostid.
• In class B, two bytes define the netid and two bytes define the
hostid.
• In class C, three bytes define the netid and one byte defines the
hostid.
55.
56. Mask
• The masks for classes A, B, and C are shown In above table.
• The concept does not apply to classes D and E.
• The mask can help us to find the netid and the hostid.
• For example, the mask for a class A address has eight 1s,
which means the first 8 bits of any address in class A define
the netid; the next 24 bits define the hostid.
• The last column of Table shows the mask in the form n where
n can be 8, 16, or 24 in classful addressing. This notation is
also called slash notation or Classless Inter domain Routing
(CIDR) notation.
57. Subnetting
• During the era of classful addressing, subnetting was
introduced.
• If an organization was granted a large block in class A or B, it
could divide the addresses into several groups and assign each
group to smaller networks (called subnets).
58. Advantages of classful addressing
• Although classful addressing had several problems and
become obsolete, it had one advantage,
• Given an address, we can easily find the class since the prefix
length of each class is fixed, we can find prefix length
immediately. i.e. no extra information needed to extract prefix
and suffix.