Frame Relay is a WAN protocol that operates at the physical and data link layers using packet switching technology. It provides connection-oriented virtual circuits between devices identified by a data-link connection identifier. Frame Relay supports both permanent virtual circuits that are always active and switched virtual circuits that are temporarily established for data transfer. It implements congestion notification using FECN, BECN and discard eligibility bits and uses CRC for error checking but not correction.
X.25 is a packet-switched network, developed by ITU-T as an interface between data terminal equipment DTE and data circuit-terminating equipment DCE for terminal operation in packet mode on public data network. It is an end-to-end protocol, but actual movement of packet through the network is invisible to the user.The user sees the network as a cloud through which each packet passes on its way to the receiving DTE.
It defines how a packet-mode terminal can be connected to a packet network for exchange of data. It describes procedures necessary for establishing, maintaining and terminating connections. It uses virtual network approach to packet switching, SVC and PVC and uses asynchronous TDM to multiplex data...
Difference between OSI Layer & TCP/IP LayerNetwax Lab
Difference between OSI Layer & TCP/IP Layer
TCP/IP OSI
It has 4 layers. It has 7 layers.
TCP/IP Protocols are considered to be standards
around which the internet has developed.
OSI Model however is a "generic, protocolindependent standard."
Follows Vertical Approach Follows Horizontal Approach
In TCP/IP Model, Transport Layer does not
Guarantees delivery of packets.
In OSI Model, Transport Layer Guarantees
delivery of packets.
X.25 is a packet-switched network, developed by ITU-T as an interface between data terminal equipment DTE and data circuit-terminating equipment DCE for terminal operation in packet mode on public data network. It is an end-to-end protocol, but actual movement of packet through the network is invisible to the user.The user sees the network as a cloud through which each packet passes on its way to the receiving DTE.
It defines how a packet-mode terminal can be connected to a packet network for exchange of data. It describes procedures necessary for establishing, maintaining and terminating connections. It uses virtual network approach to packet switching, SVC and PVC and uses asynchronous TDM to multiplex data...
Difference between OSI Layer & TCP/IP LayerNetwax Lab
Difference between OSI Layer & TCP/IP Layer
TCP/IP OSI
It has 4 layers. It has 7 layers.
TCP/IP Protocols are considered to be standards
around which the internet has developed.
OSI Model however is a "generic, protocolindependent standard."
Follows Vertical Approach Follows Horizontal Approach
In TCP/IP Model, Transport Layer does not
Guarantees delivery of packets.
In OSI Model, Transport Layer Guarantees
delivery of packets.
Point-to-Point Protocol is data link layer protocol used to establish a direct connection between two nodes via a WAN or LAN Along with is Components and Characteristics
Although the OSI reference model is universally recognized, the historical and technical open standard of the Internet is Transmission Control Protocol / Internet Protocol (TCP/IP).
The TCP/IP reference model and the TCP/IP protocol stack make data communication possible between any two computers, anywhere in the world, at nearly the speed of light.
Point-to-Point Protocol is data link layer protocol used to establish a direct connection between two nodes via a WAN or LAN Along with is Components and Characteristics
Although the OSI reference model is universally recognized, the historical and technical open standard of the Internet is Transmission Control Protocol / Internet Protocol (TCP/IP).
The TCP/IP reference model and the TCP/IP protocol stack make data communication possible between any two computers, anywhere in the world, at nearly the speed of light.
Frame Relay is a high-performance WAN protocol that operates at the physical and data link layers of
the OSI reference model. Frame Relay originally was designed for use across Integrated Services Digital
Network (ISDN) interfaces. Today, it is used over a variety of other network interfaces as well.
Frame relay is a type of WAN connection use to connect one site to many remote sites through a single
physical circuit; this operation makes it easy to construct reliable and inexpensive networks.
Frame relay is a packet-switching telecommunication service designed for cost-efficient data transmission for intermittent traffic between local area networks (LANs) and between endpoints in wide area networks (WANs).
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
1. Frame Relay
Frame Relay is a high-performance
WAN protocol that operates at the
physical and data link layers of the OSI
reference model.
Frame Relay originally was designed for
use across Integrated Services Digital
Network (ISDN) interfaces
Uses packet switching technique.
Frame Relay 1
2. Packet Switching
Frame Relay is based on packet-switched
technology.
Packet switching enables the end stations
to dynamically share network media and
bandwidth. So that it provides two type of
bandwidth CIR (Committed interface Rate),
EIR(Extended interface Rate).
The following two techniques are used in
packet-switching technology:
Variable-length packets
Statistical multiplexing
Frame Relay 2
3. Frame Relay Devices
Devices attached to a Frame Relay WAN fall into
the following two general categories:
Data terminal equipment (DTE)
Data circuit-terminating equipment (DCE)
Examples of DTE devices are terminals, personal
computers, routers, and bridges.
DCEs are carrier-owned internetworking devices.
The purpose of DCE equipment is to provide
clocking and switching services in a network,
which are the devices that actually transmit data
through the WAN. In most cases, these are packet
switches
Frame Relay 3
4. Frame Relay Virtual Circuits
Frame Relay provides connection-oriented data link layer
communication.
This service is implemented by using a Frame Relay virtual
circuit, which is a logical connection created between two data
terminal equipment (DTE) devices across a Frame Relay
packet-switched network (PSN).
Virtual circuits provide a bidirectional communication path from
one DTE device to another and are uniquely identified by a
data-link connection identifier (DLCI).
A number of virtual circuits can be multiplexed into a single
physical circuit for transmission across the network.
A virtual circuit can pass through any number of intermediate
DCE devices (switches) located within the Frame Relay PSN.
Frame Relay virtual circuits fall into two categories:
switched virtual circuits (SVCs)
permanent virtual circuits (PVCs).
Frame Relay 4
5. Switched Virtual Circuits
Switched virtual circuits (SVCs) are
temporary connections used in situations
requiring only sporadic data transfer
between DTE devices across the Frame
Relay network.
○ Call setup—The virtual circuit between two Frame
Relay DTE devices is established.
○ Data transfer—Data is transmitted between the DTE
devices over the virtual circuit.
○ Idle—The connection between DTE devices is still
active, but no data is transferred. If an SVC remains in
an idle state for a defined period of time, the call can be
terminated.
○ Call termination—The virtual circuit between DTE
devices is terminated.
Frame Relay 5
6. Permanent Virtual Circuits
Permanent virtual circuits (PVCs) are permanently
established connections that are used for frequent and
consistent data transfers between DTE devices across
the Frame Relay network.
Communication across a PVC does not require the call
setup and termination states that are used with SVCs.
○ Data transfer—Data is transmitted between the DTE devices
over the virtual circuit.
○ Idle—The connection between DTE devices is active, but no
data is transferred. Unlike SVCs, PVCs will not be terminated
under any circumstances when in an idle state.
DTE devices can begin transferring data whenever they
are ready because the circuit is permanently established.
Frame Relay 6
7. Data-Link Connection
Identifier
Frame Relay virtual circuits are identified
by data-link connection identifiers (DLCIs).
DLCI values typically are assigned by the
Frame Relay service provider (for example,
the telephone company).
Frame Relay DLCIs have local
significance, which means that their values
are unique in the LAN, but not necessarily
in the Frame Relay WAN
Frame Relay 7
8. Special DLCI numbers
DLCI 0 (zero) and 1023 are reserved for
management
DLCI 1 to 15 and 1008 to 1022 have
been reserved for future use.
DLCI 992 to 1007 are reserved for layer
2 management of frame relay bearer
service.
DLCI numbers 16 to 991 are available
for subscribers for each user frame relay
network
Frame Relay 8
9. Data-Link Connection Identifier
A Single Frame Relay Virtual Circuit Can Be Assigned Different DLCIs on Each End of a VC
Frame Relay 9
10. Congestion-Control Mechanisms
Frame Relay reduces network overhead by implementing
simple congestion-notification mechanisms rather than
explicit, per-virtual-circuit flow control.
Frame Relay implements two congestion-notification
mechanisms:
Forward-explicit congestion notification (FECN)
Backward-explicit congestion notification (BECN)
FECN and BECN each is controlled by a single bit
contained in the Frame Relay frame header.
The Frame Relay frame header also contains a Discard
Eligibility (DE) bit, which is used to identify less important
traffic that can be dropped during periods of congestion.
Frame Relay 10
11. Congestion-Control
Mechanisms
The FECN bit is part of the Address field in the
Frame Relay frame header.
The FECN mechanism is initiated when a DTE
device sends Frame Relay frames into the network.
Frame Relay 11
If the network is congested, DCE devices (switches) set the
value of the frames' FECN bit to 1. When the frames reach the
destination DTE device, the Address field (with the FECN bit
set) indicates that the frame experienced congestion in the path
from source to destination. The DTE device can relay this
information to a higher-layer protocol for processing.
Depending on the implementation, flow control may be
initiated, or the indication may be ignored.
If the network is congested, DCE devices (switches) set the
value of the frames' FECN bit to 1. When the frames reach the
destination DTE device, the Address field (with the FECN bit
set) indicates that the frame experienced congestion in the path
from source to destination. The DTE device can relay this
information to a higher-layer protocol for processing.
Depending on the implementation, flow control may be
initiated, or the indication may be ignored.
12. Congestion-Control
Mechanisms
The BECN bit is part of the Address field in the
Frame Relay frame header.
DCE devices set the value of the BECN bit to 1 in
frames traveling in the opposite direction of frames
with their FECN bit set.
This informs the receiving DTE device that a
particular path through the network is congested.
The DTE device then can relay this information to
a higher-layer protocol for processing. Depending
on the implementation, flow-control may be
initiated, or the indication may be ignored
Frame Relay 12
13. Frame Relay Discard
Eligibility
The DE bit is part of the Address field in the Frame
Relay frame header.
The Discard Eligibility (DE) bit is used to indicate
that a frame has lower importance than other
frames.
DTE devices can set the value of the DE bit of a
frame to 1 to indicate that the frame has lower
importance than other frames.
When the network becomes congested, DCE
devices will discard frames with the DE bit set.
Frame Relay 13
14. Frame Relay Error
Checking
Frame Relay uses a common error-
checking mechanism known as the cyclic
redundancy check (CRC).
The CRC compares two calculated values
to determine whether errors occurred
during the transmission from source to
destination.
Frame Relay reduces network overhead by
implementing error checking rather than
error correction.
Frame Relay 14
15. Frame Relay
Local Management
Interface
In 1990 Cisco, Digital Equipment Corporation (DEC), Northern
Telecom, and StrataCom formed a consortium to focus on its
development. They produced a protocol that provided additional
capabilities for complex inter-networking environments. These
Frame Relay extensions are referred to as the Local Management
Interface (LMI).
The LMI global addressing extension gives Frame Relay (DLCI)
values global rather than local significance. DLCI values become
DTE addresses that are unique in the Frame Relay WAN.
LMI virtual circuit status messages provide communication and
synchronization between Frame Relay DTE and DCE devices.
These messages are used to periodically report on the status of
PVCs, which prevents data from being sent into black holes (that is,
over PVCs that no longer exist).
Frame Relay 15
16. Frame Relay Frame Formats
Flags indicate the beginning and end of the frame.
Three primary components make up
the Frame Relay frame: the header and address area, the user-data
portion, and the frame check sequence (FCS).
The address area, which is 2 bytes in length, is comprised of 10 bits
representing the actual circuit identifier and 6 bits of fields related to
congestion management. This identifier commonly is referred to as the
data-link connection identifier (DLCI).
Frame Relay 16