Admission control in Internet

1. Indian Institute of Technology Patna
Presentation
On
Admission Control in Internet
Guided by
Dr. Sudhan Majhi
Submitted by
Vishal K. Waghmare
1811EE13

2. Motivation
• Internet currently provides only single class of “best-effort” service.
• No admission control and no assurances about delivery
• Existing applications are elastic.
• Tolerate delays and losses
• Can adapt to congestion
• Future “real-time” applications may be inelastic.

3. Quality of service (QoS)
▪ Quality of service (QoS) refers to any technology that manages data
traffic to reduce packet loss, latency and jitter on the network.
▪ QoS controls and manages network resources
▪ Enterprise networks need to provide predictable and measureable
services as applications -- such as voice, video and delay-sensitive
data.
▪ Organizations use QoS to meet the traffic requirements of sensitive
applications, such as real-time voice and video.

4. ▪ Organizations can achieve QoS by using certain tools and techniques,
such as jitter buffer and traffic shaping.
▪ For many organizations, QoS is included in the service-level
agreement (SLA).

5. Organizations can measure QoS quantitatively by using several parameters,
including the following:
▪ Packet loss happens when network links become congested and routers and
switches start dropping packets.
▪ When packets are dropped during real-time communication, such as a voice
or video calls, these sessions can experience jitter and gaps in speech.
▪ Jitter is the result of network congestion, timing drift and route changes.
▪ Too much jitter can degrade the quality of voice and video communication.
Quality of service (QoS) Parameters

6. ▪ Latency is the time it takes a packet to travel from its source to its
destination.
▪ Latency should be as close to zero as possible.
▪ If a voice over IP call has a high amount of latency, it can experience
echo and overlapping audio.
▪ Bandwidth is the capacity of a network communications link to
transmit the maximum amount of data from one point to another in a
given amount of time.

7. ▪ QoS optimizes the network by managing bandwidth and setting
priorities.
▪ Mean opinion score (MOS) is a measure used in the domain of
Quality of Experience
▪ Mean opinion score (MOS) is a metric to rate voice quality that uses
a five-point scale, with a five indicating the highest quality.
▪ MOS is a commonly used measure for video, audio, and audiovisual
quality evaluation.

8. Techniques To Improve The Quality of Service
▪ Scheduling
▪ FIFO QUEUING
▪ PRIORITY QUEUING
▪ WEIGHTED FAIR QUEUING
▪ Traffic Shaping
▪ LEAKY BUCKET
▪ TOKEN BUCKET
▪ Resource Reservation
▪ Admission Control

9. Admission Control
▪ Admission control is a validation process in communication
systems where a check is performed before a connection is
established to see if current resources are sufficient for the proposed
connection.
▪ Routers or switches puts restrictions on the admission of packets
from host.
▪ Before a router accepts the flow, it checks the flow for specifications
in terms of bandwidth , buffer size ,cpu speed etc.

10. ▪ For some applications, dedicated resources (such as a wavelength
across an optical network) may be needed in which case admission
control has to verify availability of such resources before a request can
be admitted.
▪ For more elastic applications, a total volume of resources may be
needed prior to some deadline in order to satisfy a new request, in
which case admission control needs to verify availability of resources
at the time and perform scheduling to guarantee satisfaction of an
admitted request
Applications

11. Admission Control Systems
▪ Asynchronous Transfer Mode(ATM)
▪ Audio Video Bridging
▪ IEEE 1394
▪ Integrated services
▪ Public switched telephone network

12. Asynchronous Transfer Mode (ATM)
▪ ATM was developed to meet the needs of the Broadband Integrated
Services Digital Network, designed to integrate telecommunication
networks.
▪ Additionally, It was designed for networks that must handle both
traditional high-throughput data traffic (e.g., file transfers), and real-
time, low-latency content such as voice and video.

13. ▪ The reference model for ATM approximately maps to the three lowest
layers of the ISO-OSI reference model: network layer, data link layer,
and physical layer.
▪ ATM is a core protocol used over the SONET/SDH backbone of the
public switched telephone network (PSTN)

14. Audio Video Bridging (AVB)
▪ Audio Video Bridging (AVB) is a common name for the set of
technical standards developed by the Institute of Electrical and
Electronics Engineers (IEEE) Audio Video Bridging Task Group of the
IEEE 802.1 standards committee.
▪ The charter of this organization is to "provide the specifications that
will allow time-synchronized low latency streaming services through
IEEE 802 networks

15. IEEE 1394
▪ IEEE 1394 is an interface standard for a serial bus for high-speed
communications and isochronous real-time data transfer.
▪ It was developed in the late 1980s and early 1990s by Apple, which
called it FireWire.

16. Integrated services
▪ In computer networking, IntServ or integrated services is an
architecture that specifies the elements to guarantee quality of service
(QoS) on networks.
▪ IntServ can for example be used to allow video and sound to reach the
receiver without interruption.
▪ IntServ specifies a fine-grained QoS system.

17. Public Switched Telephone Network (PSTN)
▪ The public switched telephone network (PSTN) is the aggregate of
the world's circuit-switched telephone networks that are operated by
national, regional, or local telephony operators, providing
infrastructure and services for public telecommunication.
▪ The PSTN consists of telephone lines, fiber optic cables, microwave
transmission links, cellular networks, communications satellites, and
undersea telephone cables, all interconnected by switching centers,
thus allowing most telephones to communicate with each other.

18. ▪ The technical operation of the PSTN adheres to the standards created
by the ITU-T.
▪ These standards allow different networks in different countries to
interconnect seamlessly.
▪ The E.163 and E.164 standards provide a single global address space
for telephone numbers.
▪ The combination of the interconnected networks and the single
numbering plan allow telephones around the world to dial each other.

19. Thank You!