quality of service
TRANSCRIPT
Computer network Quality of service
1 Depending on the installation requirements, network performance is usually measured by the quality of
service of a telecommunications product. The parameters that affect
this typically can include throughput, jitter, bit error rate and latency.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Computer network Quality of service
1 The following list gives examples of network performance measures for a
circuit-switched network and one type of packet-switched network, viz.
ATM:
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Computer network Quality of service
1 Circuit-switched networks: In circuit switched networks, network
performance is synonymous with the grade of service. The number of
rejected calls is a measure of how well the network is performing under
heavy traffic loads. Other types of performance measures can include
the level of noise and echo.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Computer network Quality of service
1 ATM: In an Asynchronous Transfer Mode (ATM) network, performance
can be measured by line rate, quality of service (QoS), data throughput, connect time, stability, technology, modulation technique and modem
enhancements.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Computer network Quality of service
1 There are many ways to measure the performance of a network, as each network
is different in nature and design. Performance can also be modelled instead of measured. For example, state transition diagrams are often used to model queuing performance in a circuit-switched network. These diagrams allow the network planner to analyze how the network will perform in each state, ensuring that the network will
be optimally designed.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Storage area network - SAN Storage QoS (Quality of Service)
1 SAN Storage QoS (Quality of Service) is the coordination of capacity and performance in a dedicated storage
area network. This enables the desired storage performance to be
calculated and maintained for network customers accessing the
device.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Storage area network - SAN Storage QoS (Quality of Service)
1 Key factors that affect Storage Area Network
QoS(Quality of Service) are:
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Storage area network - SAN Storage QoS (Quality of Service)
1 Bandwidth – The rate of data throughput available on the
system.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Storage area network - SAN Storage QoS (Quality of Service)
1 Latency – The time delay for a read/write
operation to execute.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Storage area network - SAN Storage QoS (Quality of Service)
1 Queue depth – The number of outstanding operations waiting to execute to the underlying disks
(Traditional or SSD).
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Storage area network - SAN Storage QoS (Quality of Service)
1 QoS can be impacted in a SAN storage system by unexpected increase in data
traffic (usage spike) from one network user that can cause performance to decrease for other users on the same network. This can be known as the “Noisy Neighbor Effect.” When QoS services are enabled in a SAN
storage system, the “Noisy Neighbor Effect” can be prevented and network storage
performance can be accurately predicted.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Storage area network - SAN Storage QoS (Quality of Service)
1 Using SAN storage QoS is in contrast to using disk over-provisioning in a SAN
environment. Over-provisioning can be used to provide additional capacity to
compensate for peak network traffic loads. However, where network loads are not
predictable, over-provisioning can eventually cause all bandwidth to be fully
consumed and latency to increase significantly resulting in SAN performance
degradation.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Orange S.A. - Controversies in UK regarding the quality of service
1 On 21 March 2007 Watchdog, a television series by the BBC focusing on consumer protection, published
the results from a broadband survey they held
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Orange S.A. - Controversies in UK regarding the quality of service
1 In response to the problems with Orange UK broadband and 3G
broadband during March 2009 and April 2009 the 3G data network has
been upgraded to 3.5G and increased signal coverage
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Orange S.A. - Controversies in UK regarding the quality of service
1 A consumer organisation forum web site known as OrangeProblems.co.uk focuses on
the poor level of service provided by Orange Broadband in the UK. Initially set up as WanadooProblems.co.uk, the site focuses
on the infamous Orange local loop unbundling and poor customer service but covers a wider range of Orange operations
such as lost email, significantly delayed SMTP and outages, suspicions of
eavesdropping, et al.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Orange S.A. - Controversies in UK regarding the quality of service
1 Orange Mobile has been criticised during a Channel 4 News
investigation for a lack of security which potentially exposed customer
records to fraud.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Orange S.A. - Controversies in UK regarding the quality of service
1 In August 2007 Orange was criticised for summarily deleting email
accounts tied to old Freeserve and Wanadoo 'pay as you go' dial-up
accounts with no warning.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Orange S.A. - Controversies in UK regarding the quality of service
1 In August 2008, after well publicised problems with iPhone 3G performances,
customers compared their download speed and discovered that Orange in France was capping 3G download bandwidth. Orange admitted capping to 384kbit/s, well below the theoretical 7.2Mbit/s provided by the
iPhone. This issue was addressed by Orange with the complete uncapping of the
3G and 3G+ by Mid-September 2008.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Deep packet inspection - Quality of service
1 Applications such as peer-to-peer (P2P) traffic present increasing problems for broadband service
providers
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Deep packet inspection - Quality of service
1 DPI allows the operators to oversell their available bandwidth while ensuring equitable
bandwidth distribution to all users by preventing network congestion. Additionally, a higher priority can be allocated to a VoIP or
video conferencing call which requires low latency versus web browsing which does not.
This is the approach that service providers use to dynamically allocate bandwidth
according to traffic that is passing through their networks.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 Communication on the IP network is perceived less reliable in contrast to the
circuit-switched public telephone network, as it does not provide a network-based
mechanism to ensure that data packets are not lost, and are delivered in sequential order. It is a best-effort network without
fundamental Quality of Service (QoS) guarantees. Therefore, VoIP
implementations may face problems with latency, packet loss and jitter.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 By default, network routers handle traffic on a first-come, first-served
basis. Network routers on high volume traffic links may introduce latency that exceeds permissible thresholds for VoIP. Fixed delays cannot be controlled, as they are
caused by the physical distance the packets travel; however, latency can
be minimized by marking voice packets as being delay-sensitive with
methods such as DiffServ.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 VoIP endpoints usually have to wait for completion of transmission of
previous packets, before new data may be sent
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 DSL modems provide Ethernet (or Ethernet over USB) connections to
local equipment, but inside they are actually Asynchronous Transfer Mode
(ATM) modems
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 However, a majority of DSL providers use only one VC for each customer,
even those with bundled VoIP service
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 ATM has substantial header overhead: 5/53 = 9.4%, roughly
twice the total header overhead of a 1500 byte Ethernet frame. This "ATM
tax" is incurred by every DSL user whether or not he takes advantage of multiple virtual circuits - and few can.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 ATM's potential for latency reduction is greatest on slow links, because worst-case latency decreases with
increasing link speed
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 Voice, and all other data, travels in packets over IP networks with fixed maximum
capacity. This system may be more prone to congestion and DoS attacks than traditional circuit switched systems; a circuit switched system of insufficient capacity will refuse
new connections while carrying the remainder without impairment, while the
quality of real-time data such as telephone conversations on packet-switched networks
degrades dramatically.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 Fixed delays cannot be controlled as they are caused by the physical
distance the packets travel. They are especially problematic when satellite circuits are involved because of the
long distance to a geostationary satellite and back; delays of 400–600
ms are typical.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 When the load on a link grows so quickly that its switches experience queue overflows, congestion results
and data packets are lost
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 The receiver must resequence IP packets that arrive out of order and
recover gracefully when packets arrive too late or not at all
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 Although jitter is a random variable, it is the sum of several other random variables that are at least somewhat independent: the individual queuing
delays of the routers along the Internet path in question
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 It has been suggested to rely on the packetized nature of media in VoIP communications and transmit the stream of packets from the source
phone to the destination phone simultaneously across different
routes (multi-path routing)
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 A number of protocols have been defined to support the reporting of quality of service (QoS) and quality of experience (QoE) for VoIP calls
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 RFC 3611 VoIP metrics reports are exchanged between IP endpoints on an
occasional basis during a call, and an end of call message sent via SIP RTCP Summary
Report or one of the other signaling protocol extensions. RFC 3611 VoIP metrics reports are intended to support real time feedback related to QoS problems, the exchange of
information between the endpoints for improved call quality calculation and a
variety of other applications.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Voice over IP - Quality of service
1 Rural areas in particular are greatly hindered in their ability to choose a VoIP system over
PBX
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Public utility - Public utility quality of service for telecommunications
1 Maintaining the infrastructure for a public service or utility demands a set of sound practices to enable Quality of Service (QoS). Uniform
construction procedures especially must be followed by all parties. In particular, the recent boom in new
architectures/services in telecommunications demands a
whole new set of rules to maintain uninterrupted service.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Public utility - Public utility quality of service for telecommunications
1 With new construction in public utility areas, the basic considerations and
requirements relative to the construction practices and procedures are critical in a
telecommunications company operating area.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Public utility - Public utility quality of service for telecommunications
1 It is important that any construction should minimize the possibility of creating conditions
that
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Public utility - Public utility quality of service for telecommunications
1 are hazardous to the general public and to any personnel working on, in,
or around supporting structures
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Public utility - Public utility quality of service for telecommunications
1 could impair service or the restoration of service to customers of
all parties using the supporting structures.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Public utility - Public utility quality of service for telecommunications
1 A set of practices that promotes reliable network performance and
complies with all national codes; and that is consistent with current OSHA
Rules, EPA regulations, and DOT requirements; are imperative.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Public utility - Public utility quality of service for telecommunications
1 SR-1421, Blue Book - Manual of Construction Procedures provides a basis for developing productive Joint Use agreements and collaboration with other utilities such as power
supply companies.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Public utility - Public utility quality of service for telecommunications
1 There are many OSHA rules, EPA regulations, DOT requirements, and other agencies that can affect the
operations of a telecommunications company that are not directly
covered in SR-1421, although cross references where appropriate are present. These auxiliary issues are properly addressed in specific work
rules issued by individual companies.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service
1 Quality of service
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service
1 Quality of service (QoS) is the overall performance of a of telephony or
computer network, particularly the performance seen by the users of the
network.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service
1 To quantitatively measure quality of service several related aspects of the network service are often considered,
such as error rates, bandwidth, throughput, transmission delay,
availability, jitter, etc.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service
1 Quality of service is particularly important for the transport of traffic
with special requirements. In particular, much technology has
been developed to allow computer networks to become as useful as
telephone networks for audio conversations, as well as supporting new applications with even stricter
service demands.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Definitions
1 Quality of service comprises requirements on all the aspects of a connection, such as service response
time, loss, signal-to-noise ratio, cross-talk, echo, interrupts,
frequency response, loudness levels, and so on
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Definitions
1 Quality of service guarantees are important if the network capacity is insufficient, especially for real-time streaming multimedia applications such as voice over IP, online games and IP-TV, since these often require
fixed bit rate and are delay sensitive, and in networks where the capacity is a limited resource, for example in
cellular data communication.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Definitions
1 A network or protocol that supports QoS may agree on a traffic contract with the
application software and reserve capacity in the network nodes, for example during a session establishment phase. During the
session it may monitor the achieved level of performance, for example the data rate and delay, and dynamically control scheduling
priorities in the network nodes. It may release the reserved capacity during a tear
down phase.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Definitions
1 A best-effort network or service does not support quality of service. An
alternative to complex QoS control mechanisms is to provide high
quality communication over a best-effort network by over-provisioning
the capacity so that it is sufficient for the expected peak traffic load. The
resulting absence of network congestion eliminates the need for
QoS mechanisms.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Definitions
1 QoS is sometimes used as a quality measure, with many alternative
definitions, rather than referring to the ability to reserve resources.
Quality of service sometimes refers to the level of quality of service, i.e. the guaranteed service quality. High
QoS is often confused with a high level of performance or achieved
service quality, for example high bit rate, low latency and low bit error
probability.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Definitions
1 An alternative and disputable definition of QoS, used especially in application layer services such as telephony and streaming video, is
requirements on a metric that reflects or predicts the subjectively
experienced quality
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - History
1 Conventional Internet routers and LAN switches operate on a best effort basis
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - History
1 With the advent of IPTV and IP telephony, QoS mechanisms are increasingly available to the end
user.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - History
1 A number of attempts for layer 2 technologies that add QoS tags to the data have gained popularity in the past. Examples are frame
relay, asynchronous transfer mode (ATM) and multiprotocol label switching (MPLS) (a
technique between layer 2 and 3). Despite of this network technologies are in use today,
this kind of network lost the attention by the advent of Ethernet networks. Today Ethernet
is, by far, the most popular layer 2 technology. Ethernet may offer QoS through its 802.1p.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - History
1 In Ethernet, virtual local area networks (VLAN) may be used to separate different QoS levels. For
example in fibre-to-the-home switches typically offer several
Ethernet ports connected to different VLANs. One VLAN may be used for
Internet access (low priority), one for IPTV (higher priority) and one for IP
telephony (highest priority). Different Internet service providers may use
the different VLANs.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Qualities of traffic
1 In packet-switched networks, quality of service is affected by various
factors, which can be divided into “human” and “technical” factors. Human factors include: stability of
service, availability of service, delays, user information. Technical
factors include: reliability, scalability, effectiveness, maintainability, grade
of service, etc.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Qualities of traffic
1 Many things can happen to packets as they travel from origin to
destination, resulting in the following problems as seen from the point of
view of the sender and receiver:
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Qualities of traffic
1 Due to varying load from other users sharing the same network resources,
the bit rate (the maximum throughput) that can be provided to
a certain data stream may be too low for realtime multimedia services if all
data streams get the same scheduling priority.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Qualities of traffic
1 The routers might fail to deliver (drop) some packets if their data is corrupted or they arrive when their
buffers are already full. The receiving application may ask for this
information to be retransmitted, possibly causing severe delays in the
overall transmission.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Qualities of traffic
1 Sometimes packets are corrupted due to bit errors caused by noise and
interference, especially in wireless communications and long copper
wires. The receiver has to detect this and, just as if the packet was
dropped, may ask for this information to be retransmitted.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Qualities of traffic
1 It might take a long time for each packet to reach its destination, because it gets held up in long
queues, or takes a less direct route to avoid congestion. This is different from throughput, as the delay can
build up over time, even if the throughput is almost normal. In some cases, excessive latency can render an application such as VoIP or online
gaming unusable.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Qualities of traffic
1 Packets from the source will reach the destination with different delays.
A packet's delay varies with its position in the queues of the routers along the path between source and
destination and this position can vary unpredictably. This variation in delay is known as jitter and can seriously
affect the quality of streaming audio and/or video.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Qualities of traffic
1 When a collection of related packets is routed through a network, different
packets may take different routes, each resulting in a different delay
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Applications
1 A defined quality of service may be desired or required for certain types
of network traffic, for example:
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Applications
1 Audio over Ethernet
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Applications
1 Storage applications such as iSCSI and FCoE
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Applications
1 Circuit Emulation Service
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Applications
1 Safety-critical applications such as remote surgery where availability issues can be
hazardous
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Applications
1 Network operations support systems either for the network itself, or for customers' business critical needs
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Applications
1 Industrial control systems protocols such as Ethernet/IP which are used for real-time control of machinery
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Applications
1 These types of service are called inelastic, meaning that they require a certain minimum level of bandwidth and a certain maximum latency to
function. By contrast, elastic applications can take advantage of however much or little bandwidth is
available. Bulk file transfer applications that rely on TCP are
generally elastic.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Mechanisms
1 Circuit switched networks, especially those intended for voice
transmission, such as Asynchronous Transfer Mode (ATM) or GSM, have QoS in the core protocol and do not
need additional procedures to achieve it. Shorter data units and
built-in QoS were some of the unique selling points of ATM for applications
such as video on demand.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Mechanisms
1 When the expense of mechanisms to provide QoS is justified, network customers and providers can enter into a contractual
agreement termed a service level agreement (SLA) which specifies guarantees for the
ability of a network/protocol to give guaranteed performance/throughput/latency bounds based on mutually agreed measures,
usually by prioritizing traffic. In other approaches, resources are reserved at each
step on the network for the call as it is set up.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Over-provisioning
1 An alternative to complex QoS control mechanisms is to provide high quality communication by generously over-provisioning a
network so that capacity is based on peak traffic load estimates
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Over-provisioning
1 Commercial VoIP services are often competitive with traditional telephone service
in terms of call quality even though QoS mechanisms are usually not in use on the user's connection to their ISP and the VoIP
provider's connection to a different ISP. Under high load conditions, however, VoIP may
degrade to cell-phone quality or worse. The mathematics of packet traffic indicate that
network requires just 60% more raw capacity under conservative assumptions.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Over-provisioning
1 The amount of over-provisioning in interior links required to replace QoS depends on the number of users and
their traffic demands. This limits usability of over-provisioning. Newer
more bandwidth intensive applications and the addition of more
users results in the loss of over-provisioned networks. This then requires a physical update of the relevant network links which is an
expensive process. Thus over-provisioning cannot be blindly
assumed on the Internet.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 Unlike single-owner networks, the Internet is a series of exchange points interconnecting private
networks. Hence the Internet's core is owned and managed by a number
of different network service providers, not a single entity. Its
behavior is much more stochastic or unpredictable. Therefore, research continues on QoS procedures that are deployable in large, diverse
networks.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 There are two principal approaches to QoS in modern packet-switched IP networks, a parameterized system
based on an exchange of application requirements with the network, and a prioritized system where each packet
identifies a desired service level to the network.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 Integrated services (“IntServ”) implements the parameterized
approach. In this model, applications use the Resource Reservation Protocol (RSVP) to request and
reserve resources through a network.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 Differentiated services (“DiffServ”) implements the prioritized model.
DiffServ marks packets according to the type of service they desire. In
response to these markings, routers and switches use various queueing strategies to tailor performance to
expectations. Differentiated services code point (DSCP) markings use the
first 6 bits in the ToS field of the IP(v4) packet header.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 Early work used the integrated services (IntServ) philosophy of reserving network
resources
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 In response to these markings, routers and switches use various
queuing strategies to tailor performance to requirements. At the IP layer, differentiated services code point (DSCP) markings use the 6 bits in the IP packet header. At the MAC layer, VLAN IEEE 802.1Q and IEEE
802.1p can be used to carry essentially the same information.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 Routers supporting DiffServ configure their network scheduler to use
multiple queues for packets awaiting transmission from bandwidth constrained (e.g., wide area)
interfaces. Router vendors provide different capabilities for configuring this behavior, to include the number
of queues supported, the relative priorities of queues, and bandwidth
reserved for each queue.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 In practice, when a packet must be forwarded from an interface with
queuing, packets requiring low jitter (e.g., VoIP or videoconferencing) are given priority over packets in other
queues. Typically, some bandwidth is allocated by default to network
control packets (such as Internet Control Message Protocol and routing
protocols), while best effort traffic might simply be given whatever
bandwidth is left over.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 At the Media Access Control (MAC) layer, VLAN IEEE 802.1Q and IEEE
802.1p can be used distinguish between Ethernet frames and
classify them. Queueing theory models have been developed on
performance analysis and QoS for MAC layer protocols.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - IP and Ethernet efforts
1 One compelling example of the need for QoS on the Internet relates to congestion collapse
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Protocols
1 The type of service (ToS) field in the IP(v4) header (now superseded by DiffServ)
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Protocols
1 The ITU-T G.hn standard provides QoS by means of “Contention-Free
Transmission Opportunities” (CFTXOPs) which are allocated to
flows which require QoS and which have negotiated a “contract” with the network controller. G.hn also supports non-QoS operation by
means of “Contention-based Time Slots”.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Protocols
1 Audio Video Bridging
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - End-to-end quality of service
1 End-to-end quality of service can require a method of coordinating resource allocation between one autonomous system and another
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - End-to-end quality of service
1 Research consortia such as "end-to-end quality of service support over heterogeneous networks" (EuQoS, from 2004 through 2007) and fora
such as the IPsphere Forum developed more mechanisms for handshaking QoS invocation from
one domain to the next
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - End-to-end quality of service
1 It included a "Quality of Service
Theme" and published a book
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - End-to-end quality of service
1 In the services domain, end-to-end Quality of Service has also been
discussed in the case of composite services (consisting of atomic
services) or applications (consisting of application components).
Moreover, in cloud computing end-to-end QoS has been the focus of
various research efforts aiming at the provision of QoS guarantees across
the cloud service models.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Circumvention
1 Strong cryptography network protocols such as Secure Sockets
Layer, I2P, and virtual private networks obscure the data
transferred using them. As all electronic commerce on the Internet
requires the use of such strong cryptography protocols, unilaterally
downgrading the performance of encrypted traffic creates an
unacceptable hazard for customers. Yet, encrypted traffic is otherwise unable to undergo deep packet
inspection for QoS.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Doubts about quality of service over IP
1 The Internet2 project found, in 2001, that the QoS protocols were probably
not deployable inside its Abilene Network with equipment available at
that time
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Doubts about quality of service over IP
1 The Abilene network study was the basis for the testimony of Gary
Bachula to the US Senate Commerce Committee's hearing on Network
Neutrality in early 2006. He expressed the opinion that adding
more bandwidth was more effective than any of the various schemes for accomplishing QoS they examined.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Doubts about quality of service over IP
1 Bachula's testimony has been cited by proponents of a law banning
quality of service as proof that no legitimate purpose is served by such
an offering. This argument is dependent on the assumption that
over-provisioning isn't a form of QoS and that it is always possible. Cost
and other factors affect the ability of carriers to build and maintain permanently over-provisioned
networks.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Mobile (cellular) QoS
1 Mobile cellular service providers may offer mobile QoS to customers just as the fixed line PSTN services providers and Internet Service Providers (ISP)
may offer QoS. QoS mechanisms are always provided for circuit switched services, and are essential for non-
elastic services, for example streaming multimedia.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Mobile (cellular) QoS
1 A phone call or other session may be interrupted after a handover, if the
new base station is overloaded. Unpredictable handovers make it
impossible to give an absolute QoS guarantee during a session initiation
phase.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Mobile (cellular) QoS
1 The pricing structure is often based on per-minute or per-megabyte fee rather than flat rate, and may be
different for different content services.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Mobile (cellular) QoS
1 A crucial part of QoS in mobile communications is Grade of Service,
involving outage probability (the probability that the mobile station is outside the service coverage area, or affected by co-channel interference,
i.e
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Standards
1 Quality of service in the field of telephony, was first defined in 1994 in the ITU-T Recommendation E.800
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Standards
1 Some QoS-related IETF Request For Comments (RFC)s are Definition of the
Differentiated services Field (DS Field) in the IPv4 and IPv6 Headers (RFC 2474), and
Resource ReSerVation Protocol (RSVP) (RFC 2205); both these are discussed above. The
IETF has also published two RFCs giving background on QoS: RFC 2990: Next Steps for the IP QoS Architecture, and RFC 3714: IAB Concerns Regarding Congestion Control
for Voice Traffic in the Internet.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Standards
1 The IETF has also published RFC 4594 Configuration Guidelines for
DiffServ Service Classes as an informative or "best practices" document about the practical
aspects of designing a QoS solution for a DiffServ network
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Open source software
1 Linux Advanced Routing & Traffic Control (from 2000 to
2005)
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Further reading
1 Deploying IP and MPLS QoS for Multiservice Networks: Theory and Practice by John Evans, Clarence Filsfils (Morgan Kaufmann, 2007,
ISBN 0-12-370549-5)
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Further reading
1 Lelli, F. Maron, G. Orlando, S. Client Side Estimation of a Remote Service
Execution. 15th International Symposium on Modeling, Analysis, and Simulation of Computer and
Telecommunication Systems, 2007. MASCOTS '07.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Further reading
1 QoS Over Heterogeneous Networks by Mario Marchese (Wiley, 2007, ISBN 978-0-470-
01752-4)
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Further reading
1 XiPeng Xiao (September 8, 2008). Technical, Commercial and
Regulatory Challenges of QoS: An Internet Service Model Perspective. Morgan Kaufmann. ISBN 978-0-12-
373693-2.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Further reading
1 RFC 1633: Integrated Services in the Internet
Architecture: an Overview
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality of service - Further reading
1 RFC 2475: An Architecture for Differentiated
services
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Multitenancy - Quality of service
1 Multitenant applications are expected to provide adequate levels of security and robustness, which are provided by the operating system in
the case of multi-instance applications.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Outsourcing - Quality of service (QoS)
1 Quality of service is best measured through customer satisfaction
questionnaires which are designed to capture an unbiased view.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Computer networking - Quality of service
1 *Circuit-switched networks: In circuit switched networks, network
performance is synonymous with the grade of service. The number of
rejected calls is a measure of how well the network is performing under
heavy traffic loads. Other types of performance measures can include
the level of noise and echo.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Computer networking - Quality of service
1 *ATM: In an Asynchronous Transfer Mode (ATM) network, performance
can be measured by line rate, quality of service (QoS), data throughput, connect time, stability, technology, modulation technique and modem enhancements., Americas January
2003, Issue Highlights, Online Exclusive: Broadband Access
Maximum Performance, Retrieved on February 13, 2005.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet telephony - Quality of service
1 Communication on the IP network is perceived as less reliable in contrast
to the circuit-switched public telephone network because it does
not provide a network-based mechanism to ensure that data
packets are not lost, and are delivered in sequential order. It is a
best-effort network without fundamental Quality of Service (QoS)
guarantees. Therefore, VoIP implementations may face problems with latency (engineering)|latency,
packet loss, and jitter.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet telephony - Quality of service
1 DSL modems provide Ethernet (or Ethernet over Universal Serial Bus|
USB) connections to local equipment, but inside they are actually
Asynchronous Transfer Mode (ATM) modems
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet telephony - Quality of service
1 ATM's potential for latency reduction is greatest on slow links, because worst-case latency decreases with
increasing link speed
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet telephony - Quality of service
1 Voice, and all other data, travels in packets over IP networks with fixed maximum
capacity
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet telephony - Quality of service
1 When the load on a link grows so quickly that its switches experience queue overflows, congestion results
and data packets are lost
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet telephony - Quality of service
1 It has been suggested to rely on the packetized nature of media in VoIP communications and
transmit the stream of packets from the source phone to the destination phone simultaneously
across different routes (multi-path routing).[http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?
arnumber=4520089 IEEE Multipath routing with adaptive playback scheduling for Voice over IP in Service Overlay Networks (Abstract)] In such a way, temporary failures have less impact on
the communication quality
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet telephony - Quality of service
1 A number of protocols have been defined to support the reporting of quality of service (QoS) and quality of experience (QoE) for VoIP calls
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet telephony - Quality of service
1 RFC3611 VoIP metrics reports are exchanged between IP endpoints on an occasional basis
during a call, and an end of call message sent via SIP RTCP Summary Report or one of
the other signaling protocol extensions. RFC3611 VoIP metrics reports are intended
to support real time feedback related to QoS problems, the exchange of information
between the endpoints for improved call quality calculation and a variety of other
applications.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Network Neutrality - Quality of service
1 Internet routers forward packets according to the diverse peering and
transport agreements that exist between network operators. Many networks using Internet protocols
now employ quality of service (QoS), and Network Service Providers
frequently enter into Service Level Agreements with each other embracing some sort of QoS.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Network Neutrality - Quality of service
1 There is no single, uniform method of interconnecting networks using Internet Protocol|IP, and not all
networks that use IP are part of the Internet. IPTV networks are isolated from the Internet, and are therefore not covered by network neutrality
agreements.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Network Neutrality - Quality of service
1 The IP datagram includes a 3-bit wide Precedence field and a larger
DiffServ Code Point that are used to request a level of service, consistent
with the notion that protocols in a layered architecture offer services
through Service Access Points
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Network Neutrality - Quality of service
1 With the emergence of multimedia, VoIP, IPTV, and other applications
that benefit from low latency, various attempts to address the inability of
some private networks to limit latency have arisen, including the
proposition of offering tiered service levels that would shape Internet
transmissions at the network layer based on application type
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Network Neutrality - Quality of service
1 He argues that since implementing quality of service doesn't require any
additional costs versus a non-QoS network, there's no reason
implementing quality of service should entail any additional fees
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Network Neutrality - Quality of service
1 Xipeng Xiao covers the relationship between QoS and Network Neutrality
in the book Technical, Commercial and Regulatory Challenges of QoS:
An Internet Service Model Perspective.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
France Telecom - Controversies in UK regarding the quality of service
1 On 21 March 2007 Watchdog (TV series)|Watchdog, a television
program|television series by the BBC focusing on consumer protection,
published the results from a broadband Survey methodology|
survey they held
https://store.theartofservice.com/the-quality-of-service-toolkit.html
France Telecom - Controversies in UK regarding the quality of service
1 A consumer organization|consumer organisation internet forum|forum web site known as
OrangeProblems.co.uk focuses on the poor level of service provided by Orange Broadband in the UK. Initially set up as WanadooProblems.co.uk, the site focuses on the infamous Orange local-loop unbundling|local loop unbundling and poor customer service but covers a wider range of
Orange operations such as lost email, significantly delayed SMTP and outages,
suspicions of eavesdropping, et al.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
France Telecom - Controversies in UK regarding the quality of service
1 Orange Mobile has been criticised during a Channel 4 News
investigation for a lack of security which potentially exposed customer
records to fraud.[http://wayback.archive.org/web/20070621074012/http://www.chan
nel4.com/news/articles/business_money/concern%20over%20mobile%20security/172350
Channel 4 News]https://store.theartofservice.com/the-quality-of-service-toolkit.html
France Telecom - Controversies in UK regarding the quality of service
1 In August 2008, after well publicised problems with iPhone 3G
performances, customers compared their download speed and discovered
that Orange in France was capping 3G download bandwidth
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Multitenant - Quality of service
1 Multitenant applications are expected to provide adequate levels of Computer security|security and Robustness (computer science)|
robustness, which are provided by the operating system in the case of
multi-instance applications.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Grid-tied electrical system - Quality of service
1 A key concept of this system is the possibility of creating an electrical
micro-system that is not dependent on the grid-tie to provide the high
level of service quality which is often delivered by a traditional mains
supply.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Grid-tied electrical system - Quality of service
1 Conversely if the mains supply of the region is unreliable, the local
generation system can be used to power important equipment.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Orange (telecommunications) - Controversies in UK regarding the quality of service
1 On 21 March 2007 Watchdog (TV series)|Watchdog, a television series
by the BBC focusing on consumer protection, published the results from
a broadband Statistical survey|survey they held
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Orange (telecommunications) - Controversies in UK regarding the quality of service
1 A consumer organisation internet forum|forum web site known as
OrangeProblems.co.uk focuses on the poor level of service provided by Orange
Broadband in the UK. Initially set up as WanadooProblems.co.uk, the site focuses on the infamous Orange local loop unbundling
and poor customer service but covers a wider range of Orange operations such as lost email, significantly delayed SMTP and
outages, suspicions of eavesdropping, et al.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Femtocell - Quality of service
1 When using an ethernet or ADSL home backhaul connection, an Access Point Base Station must
either share the backhaul bandwidth with other services, such as Internet browsing, gaming consoles, set-top
boxes and triple play (telecommunications)|triple-play
equipment in general, or alternatively directly replace these
functions within an integrated unit. In shared-bandwidth approaches, which are the majority of designs currently
being developed, the effect on quality of service may be an issue.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Femtocell - Quality of service
1 The uptake of femtocell services will depend on the reliability and quality
of both the cellular operator’s network and the third-party
broadband connection, and the broadband connection’s subscriber
understanding the concept of bandwidth utilization by different applications a subscriber may use
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Femtocell - Quality of service
1 A key issue recently identified is active traffic shaping by many ISPs on the underlying
transport protocol IPSec. UK-based femtocell benchmarking company Epitiro have published
whitepapers about these IP-focused QoS issues.Newson, A. (November 25, 2008).
[http://www.thinkfemtocell.com/downloads/white-papers/11-epitiro-femtocell-deployment-guide/download.html Femtocell Deployment
Guide]. ThinkFemtoCell.com. Epitiro.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
SMS Banking - Quality of service in SMS banking
1 Because of the concerns made explicit above, it is extremely important that SMS gateway
providers can provide a decent quality of service for banks and
financial institutions in regards to SMS services
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Utility companies - Public utility quality of service for telecommunications
1 Maintaining the infrastructure for a public service or utility demands a set of sound practices to enable
Quality of Service (QoS). Uniform construction procedures especially must be followed by all parties. In particular, the recent boom in new
architectures/services in telecommunications demands a
whole new set of rules to maintain uninterrupted service.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Utility companies - Public utility quality of service for telecommunications
1 * are hazardous to the general public and to any personnel working on, in,
or around supporting structures
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Utility companies - Public utility quality of service for telecommunications
1 * could impair service or the restoration of service to customers of
all parties using the supporting structures.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Utility companies - Public utility quality of service for telecommunications
1 [http://telecom-info.telcordia.com/site-cgi/ido/docs.cgi?
ID=SEARCHDOCUMENT=SR-1421 SR-1421, Blue Book - Manual of
Construction Procedures] provides a basis for developing productive Joint Use agreements and collaboration with other utilities such as power
supply companies.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Bharat Sanchar Nigam Limited - Quality of Service
1 BSNL goes by the motto Connecting India, faster and displays the same at
their homepage. BSNL offers seamless coverage in almost all urban and rural areas of India.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
SANoIP - SAN Storage QoS (Quality of Service)
1 *Bandwidth (computing)|Bandwidth – The rate of data throughput available on the
system.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
SANoIP - SAN Storage QoS (Quality of Service)
1 *Latency (engineering)|Latency – The time delay for a read/write operation to execute.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
SANoIP - SAN Storage QoS (Quality of Service)
1 *Queue depth – The number of outstanding operations waiting to execute to the underlying disks
(Traditional or SSD).
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Specialized Mobile Radio - Quality of service
1 In SMR systems, many factors affect the quality of service. This may include the capacity of the radio
system versus the number of radio units using the system. A talkative user community may cause busy
signals while a disciplined, professional group of SMR users may
keep channels idle.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Specialized Mobile Radio - Quality of service
1 Some systems experience seasonal peaks
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Specialized Mobile Radio - Quality of service
1 Siting of the system affects coverage: the system Antenna
(radio)|antennas should overlook the desired coverage area. Federal Communications Commission
regulations require systems using the same radio frequency to be spaced 70 miles from one another or do an engineering study to confirm there will be no interference from closer
spacing. https://store.theartofservice.com/the-quality-of-service-toolkit.html
Specialized Mobile Radio - Quality of service
1 Maintenance practices also can affect quality. In some systems, the
operator may remove one channel of a trunked system from service to perform repairs. In a heavily-used
system, this could cause busy signals.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Specialized Mobile Radio - Quality of service
1 Engineering documentation for these systems suggests another evaluation would be delivered audio quality. This
is a measurement of the sound quality over all of the involved pieces of communications equipment from
end to end. The first clue this may be an issue is that radio users with
normal hearing have trouble understanding others when speaking
over the radio.https://store.theartofservice.com/the-quality-of-service-toolkit.html
Videotelephony - Categories by cost and quality of service
1 Quality of service can range from low to very high, including High-definition video|high definition video available
on the latest model webcams
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Videotelephony - Categories by cost and quality of service
1 * Videophones –low to midrange cost. The earliest standalone models
operated over either plain Plain old telephone service|POTS telephone
lines on the PSTN telephone networks or more expensive ISDN
lines, while newer models have largely migrated to Internet protocol
line service for higher image resolutions and sound quality. Quality
of service for standalone videophones can vary from low to
high;
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Videotelephony - Categories by cost and quality of service
1 * Videoconferencing|Videoconferencing systems –
midrange cost, usually utilizing multipoint control units or other
bridging services to allow multiple parties on a videoconference calls.
Quality of service can vary from moderate to high;
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Videotelephony - Categories by cost and quality of service
1 * Telepresence|Telepresence systems –highest capabilities and highest cost. Full
high-end systems can involve specially built teleconference rooms to allow expansive views with very high levels of audio and video fidelity, to permit an 'immersive'
videoconference. When the proper type and capacity transmission lines are provided between facilities, the quality of service
reaches state-of-the-art levels.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality-of-service - End-to-end quality of service
1 RSVP is an end-to-end principle|end-to-end bandwidth reservation
protocol. The traffic engineering version, RSVP-TE, is used in many
networks to establish traffic-engineered Multiprotocol Label Switching (MPLS) label-switched
paths.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality-of-service - End-to-end quality of service
1 Research consortia such as end-to-end quality of service support over heterogeneous networks (EuQoS, from 2004 through 2007) and fora such
as the IPsphere Forum[http://www.tmforum.org/ipsphere/
IPSphere: Enabling Advanced Service Delivery] developed more mechanisms for handshaking QoS invocation from one domain to the next.
IPsphere defined the Service Structuring Stratum (SSS) signaling bus in order to
establish, invoke and (attempt to) assure network services.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality-of-service - End-to-end quality of service
1 A broader European project called Architecture and design for the
future Internet known as 4WARD had a budgest estimated at 23.4 million Euro and was funded from January
2008 through June 2010.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality-of-service - End-to-end quality of service
1 It included a Quality of Service Theme and published a
book.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality-of-service - End-to-end quality of service
1 Varvarigou, An innovative Workflow Mapping Mechanism for Grids in the frame of Quality of Service, Elsevier
Future Generation Computer Systems, Vol
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Quality-of-service - Doubts about quality of service over IP
1 The Abilene network study was the basis for the testimony of Gary Bachula to the
United States Senate Committee on Commerce, Science and Transportation|
US Senate Commerce Committee's hearing on Network Neutrality in early 2006. He expressed the opinion that adding more bandwidth was more
effective than any of the various schemes for accomplishing QoS they examined.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Vonage - Quality of service and equipment compatibility
1 VoIP service relies upon consistent broadband-ISP uptime and VoIP-equipment compatibility with the
ISP's modem
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Vonage - Quality of service and equipment compatibility
1 Vonage implements Voice over IP sending audio via Real-time transport
protocol|RTP and signaling via Session Initiation Protocol|SIP.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Media independent handover - Quality of Service (QoS)
1 Short-lived sessions such as accessing a single web page typically
do not require handover or QoS. Longer duration sessions, which may well require handover, such as VoIP, audio/video streaming (including live
TV and VoD), and VPNs, typically have QoS requirements including delay, delay variation and packet
loss. https://store.theartofservice.com/the-quality-of-service-toolkit.html
Media independent handover - Quality of Service (QoS)
1 It is important that QoS is maintained, not just before and after
a handover, but also during the handover, and this can be achieved
by using MIH to plan ahead
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Media independent handover - Quality of Service (QoS)
1 QoS is handled differently by each technology, including both the
wireless access technologies and also IP, which has two QoS
approaches, DiffServ and IntServ
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Media independent handover - Quality of Service (QoS)
1 MIH can be used to exchange information about service class and QoS parameter availability from one wireless technology to another and to the IP layer. One source of such
information is performance measurements made by the wireless
layer, e.g. 802.11k for WiFi and 802.16f for WiMAX.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Cross-layer optimization - Adjusting quality of service
1 Cross-layer optimization shall contribute to an improvement of quality of services under various
operational conditions. Such adaptive quality of service management is currently subject of various patent
applications, as e.g.[http://www.patentstorm.us/paten
ts/7339897.html Cross-layer integrated collision free path routing
- US Patent 7339897] https://store.theartofservice.com/the-quality-of-service-toolkit.html
Cross-layer optimization - Adjusting quality of service
1 The cross-layer control mechanism provides a feedback on concurrent quality information for the adaptive setting of control parameters. The
control scheme apply
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Cross-layer optimization - Adjusting quality of service
1 * the observed quality parameters
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Cross-layer optimization - Adjusting quality of service
1 * a fuzzy logic based reasoning about applying the appropriate control strategy
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Cross-layer optimization - Adjusting quality of service
1 * the statistically computed control input to parameter settings and mode switches
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Traffic contract - Quality of Service (QoS) Parameters
1 A set of parameters are negotiated when a connection is set up in an
ATM network. These parameters are used to measure the Quality of
Service|QoS of a connection and quantify end-to-end network
performance at the ATM layer. The network should guarantee the
negotiated QoS by meeting certain values of these parameters.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Traffic contract - Quality of Service (QoS) Parameters
1 *Cell Transfer Delay (CTD). The delay experienced by a cell between the time it takes for the first bit of the
cell to be transmitted by the source and the last bit of the cell to be
received by the destination. Maximum Cell Transfer Delay (Max CTD) and Mean Cell Transfer Delay
(Mean CTD) are used.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Traffic contract - Quality of Service (QoS) Parameters
1 *Peak-to-peak Cell Delay Variation (CDV). The difference between the
maximum and minimum CTD experienced during the connection.
Peak-to-peak CDV and Instantaneous CDV are used.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Traffic contract - Quality of Service (QoS) Parameters
1 *Cell Loss Ratio (CLR). The percentage of cells that are lost in
the network due to error or congestion and are not received by
the destination.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Cellular traffic - Quality of Service targets
1 At the time that the cells of a radio subsystem are designed, Mobile QoS|Quality of Service (QoS) targets are
set, for: traffic congestion and blocking, dominant coverage area,
C/I, dropped call rate, handover failure rate, overall call success
rate, ...
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Water supply and sanitation in Guatemala - Quality of service
1 The water and sanitation sector in Guatemala is characterized by “low
coverage, poor Water_supply#Service_quality|quality
services, and deteriorating physical assets,” related to a need for increased investments in basic infrastructures. Population growth,
agricultural expansion, unevenly distributed services, and polluted sources have
contributed to the inability of citizens to access adequate amounts of clean water.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet phone - Quality of service
1 VoIP endpoints usually have to wait for completion of transmission of previous packets before new data
may be sent
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Internet phone - Quality of service
1 Voice, and all other data, travels in packets over IP networks with fixed maximum capacity. This system may be more prone to congestion and Denial-of-service attack|DoS attacks than traditional circuit switched systems; a circuit switched system of insufficient capacity will refuse new connections while carrying the remainder without impairment, while the
quality of real-time data such as telephone conversations on packet-switched networks
degrades dramatically.
https://store.theartofservice.com/the-quality-of-service-toolkit.html
Orange Mobile - Controversies in UK regarding the quality of service
1 On 21 March 2007 Watchdog (TV series)|Watchdog, a television
program|television series by the BBC focusing on consumer protection,
published the results from a broadband Survey methodology|
survey they held
https://store.theartofservice.com/the-quality-of-service-toolkit.html
For More Information, Visit:
• https://store.theartofservice.com/the-quality-of-service-toolkit.html
The Art of Servicehttps://store.theartofservice.com