![Implementing QoS with AutoQoS
[trust] option is used to trust DSCP marking
– AutoQoS VoIP supported both in
the LAN and WAN environments
– AutoQoS Enterprise supported
on WAN interfaces
– Routers can deploy Enterprise
QoS policy treatment for voice,
video, and data traffic
– Switches can deploy QoS policy
treatments for voice by a single
command](https://image.slidesharecdn.com/presentacion-qos-220222023039/85/Presentacion-qos-43-320.jpg)
Presentacion qos-
- 1. RED1PROYDESA L ATA M S D LU L TID N L E A R NING S . SERVI CES FUNDACION PROYDESA PROYECTOS Y DESARROLLOS ARGENT I NOS
- 3. Introducción de QoS Comprendiendo la necesidad de QoS
- 5. Before Converged Networks Traditional data traffic characteristics: – Bursty data flow – First-come, first-served access – Mostly not time-sensitive – delays OK – Brief outages are survivable
- 6. Después de las redes convergentes Características tradicionales del tráfico de datos: Flujo de datos en ráfagas Acceso por orden de llegada La mayoría de las veces no es sensible al tiempo, si hay retrasos no hay problema Se puede sobrevivir a breves interrupciones
- 7. Redes convergentes: problemas de calidad – Llamada Telefónica: “I cannot understand you; your voice is breaking up.” – Teleconferencia: “The picture is very jerky. Voice not synchronized.” – Casa de Bolsa: “I needed that information two hours ago. Where is it?” – Call Center: “Please hold while my screen refreshes.”
- 8. Requisitos de tráfico de QoS: Datos • Diferentes aplicaciones tienen diferentes características de tráfico. Diferentes versiones de la misma aplicación puede tener diferentes características de tráfico. Clasifique los datos en un modelo de prioridad relativa con no más de cuatro a cinco clases: • • – Apps de misión crítica: aplicaciones críticas definidas localmente – Transaccional: tráfico interactivo, servicio de datos preferido – Mejor esfuerzo: Internet, correo electrónico, tráfico no especificado – Menos que el mejor esfuerzo (Scavenger): Napster, Kazaa, aplicaciones de igual a igual Suave o ráfaga Benigno o codicioso Insensible a las caídas Insensible al retraso Retransmisiones de TCP
- 9. QoS Traffic Requirements: Voice • • • • Latency < 150 ms* Jitter < 30 ms* Loss < 1%* 17-106 kbps guaranteed priority bandwidth per cal– l 150 bps (+ Layer 2 QoS ve T rh ra e fa fid c)Requirements: Voice guaranteed bandwidth for voice-control traffic per call • *one-way requirements Fluido Benigno Sensible a las Caídas Sensible a Demoras Prioridad UDP
- 10. QoS Requirements: Videoconferencing • Latency ≤ 150 ms* • Jitter ≤ 30 ms* • Loss ≤ 1%* • Minimum priority bandwidth guarantee required is: – Video stream + 20% – For example, a 384 kbps stream would require 460 kbps of priority bandwidth *one-way requirements Ráfaga Ávido Sensible a las Caídas Sensible a Demoras Prioridad UDP
- 11. Converged Networks: Quality Issues (Cont.) – Lack of bandwidth: Multiple flows compete for a limited amount of bandwidth. – End-to-end delay (fixed and variable): Packets have to traverse many network devices and links that add up to the overall delay. – Variation of delay (jitter): Sometimes there is a lot of other traffic, which results in more delay. – Packet loss: Packets may have to be dropped when a link is congested. Video Lacking Proper QoS
- 12. – Best-Effort: No QoS is applied to packets. – IntServ: Applications signal to the network that they require special QoS. – DiffServ: The network recognizes classes that require special QoS.
- 13. Best-Effort Model Llegará ahí cuando llegue. – Internet initially based on a best- effort packet delivery service – The default mode for all traffic – No differentiation between types of traffic – Like using standard mail
- 14. Best-Effort Model (Cont.) + Benefits: • Highly scalable • No special mechanisms required Drawbacks: • No service guarantees • No service differentiation –
- 15. IntServ Model – Some applications have special bandwidth or delay requirements or both – IntServ introduced to guarantee a predictable behavior of the network for these applications – Guaranteed delivery: no other traffic can use reserved bandwidth – Like having your own private courier plane It will be there by 10:30 a.m.
- 16. IntServ Model (Cont.) – Provides multiple service levels – Requests specific kind of service from the network before sending data – Uses RSVP to reserve network resources – Uses intelligent queuing mechanisms – End to end
- 17. – RSVP QoS services • • Guaranteed-rate service Controlled-load service – RSVP provides policy to QoS mechanisms IntServ Model (Cont.)
- 18. IntServ Model (Cont.) + Benefits: • • Explicit resource admission control (end to end) Per-request policy admission control (authorization object, policy object) Signaling of dynamic port numbers (for example, H.323) • – Drawbacks: • • Continuous signaling because of stateful architecture Flow-based approach not scalable to large implementations such as the public Internet (can be made more scalable when combined with elements of the DiffServ model)
- 19. DiffServ Model – Network traffic identified by class – Network QoS policy enforces differentiated treatment of traffic classes – You choose level of service for each traffic class – Like using a package delivery service • Do you want overnight delivery? Do you want two-day air • delivery? • Do you want three- to seven-day ground delivery?
- 21. QoS for Converged Networks
- 22. Step 1: Identify Traffic and Its Requirements – Network audit • Identify traffic on the network – Business audit • Determine how each type of traffic is important for business – Service levels required • Determine required response time
- 23. Step 2: Divide Traffic into Classes
- 24. Classification – Classification is the identifying and splitting of traffic into different classes. – Traffic can be classed by various means, including the DSCP. – Modular QoS CLI allows classification to be implemented separately from policy.
- 25. Calificación – Marking, also known as coloring, marks each packet as a member of a network class so that the packet class can be quickly recognized throughout the rest of the network.
- 26. Differentiated Services Model – The Differentiated Services model describes services associated with traffic classes. – Complex traffic classification and conditioning is performed at the network edge, resulting in a per-packet DSCP. – No per-flow state in the core. – The core only performs simple “per-hop behaviors” on traffic aggregates. – The goal is scalability.
- 27. DSCP Encoding – DiffServ field: The IP version 4 header ToS octet or the IPv6 traffic class octet, when interpreted in conformance with the definition given in RFC 2474 – DSCP: The first six bits of the DiffServ field, used to select a PHB (forwarding and queuing method)
- 28. DiffServ Model (Cont.) + Benefits: • Highly scalable • Many levels of quality possible – Drawbacks: • • No absolute service guarantee Complex mechanisms
- 29. QoS for Converged Networks
- 30. QoS Mechanisms – Classification: Each class-oriented QoS mechanism has to support some type of classification. – Marking: Used to mark packets based on classification, metering, or both. – Congestion management: Each interface must have a queuing mechanism to prioritize transmission of packets. – Congestion avoidance: Used to drop packets early to avoid congestion later in the network. – Policing and shaping: Used to enforce a rate limit based on the metering (excess traffic is either dropped, marked, or delayed). – Link Efficiency: Used to improve bandwidth efficiency through compression, link fragmentation, and interleaving.
- 31. Classification – Classification is the identifying and splitting of traffic into different classes. – Traffic can be classed by various means, including the DSCP. – Modular QoS CLI allows classification to be implemented separately from policy.
- 32. Marking – Marking, also known as coloring, marks each packet as a member of a network class so that the packet class can be quickly recognized throughout the rest of the network.
- 33. Congestion Management – Congestion management uses the marking on each packet to determine in which queue to place packets. – Congestion management uses sophisticated queuing technologies, such as WFQ and LLQ, to ensure that time-sensitive packets such as voice are transmitted first.
- 34. Congestion Avoidance – Congestion avoidance may randomly drop packets from selected queues when previously defined limits are reached. – By dropping packets early, congestion avoidance helps prevent bottlenecks downstream in the network. – Congestion avoidance technologies include random early detection and weighted random early detection.
- 35. Policing – Policing drops or marks packets when a predefined limit is reached.
- 36. Organización – Shaping queues packets when a predefined limit is reached.
- 37. Compression – Header compression can dramatically reduce the overhead associated with voice transport.
- 38. Link Fragmentation and Interleaving – Without link fragmentation and interleaving, time-sensitive voice traffic can be delayed behind long, non-time-sensitive data packets. – Link fragmentation breaks long data packets apart and interleaves time- sensitive packets so that the time-sensitive packets are not delayed.
- 39. Applying QoS to Input and Output Interfaces
- 40. Methods for Implementing QoS Policy – CLI – MQC – AutoQoS VoIP (voice QoS) – AutoQoS Enterprise (voice, video, and data QoS) – QPM
- 41. Implementing QoS with CLI interface Multilink1 ip address 10.1.61.1 255.255.255.0 ip tcp header-compression iphc-format load-interval 30 custom-queue-list 1 ppp multilink ppp multilink fragment-delay 10 ppp multilink interleave multilink-group 1 ip rtp header-compression iphc-format ! – Traditional method – Nonmodular – Cannot separate traffic classification from policy definitions – Used to augment, fine-tune newer AutoQoS method
- 42. Implementing QoS with MQC • • A command syntax for configuring QoS policy • Reduces configuration steps and time • Configure policy, not “raw” per-interface commands • Uniform CLI across major Cisco IOS platforms • Uniform CLI structure for all QoS features • Separates classification engine from the policy • • • • • • class-map VoIP-RTP match access-group 100 class-map VoIP-Control match access-group 101 • ! •policy-map QoS- Policy class VoIP-RTP •priority 100 class VoIP-Control bandwidth 8 class class-default fair-queue • ! • interface serial 0/0 • service-policy output QoS-Policy • ! • access-list 100 permit ip any any precedence 5 access-list 100 permit ip any any dscp ef • access-list 101 permit tcp any host 10.1.10.20 range 2000 2002 • access-list 101 permit tcp any host 10.1.10.20 range 11000 11999
- 43. Implementing QoS with AutoQoS [trust] option is used to trust DSCP marking – AutoQoS VoIP supported both in the LAN and WAN environments – AutoQoS Enterprise supported on WAN interfaces – Routers can deploy Enterprise QoS policy treatment for voice, video, and data traffic – Switches can deploy QoS policy treatments for voice by a single command