Qual é o modelo de QoS de 5 níveis (através do exemplo de configuração)?


13

Eu ouvi pessoas dizendo que sua rede

"opera um modelo de QoS de 5 níveis (ou camada)"

Às vezes, eles também mencionam um modelo de QoS de 7 níveis. Alguém pode me fornecer um exemplo de configuração do Cisco IOS do que se entende aqui. Então, com isso, quero dizer um exemplo de configuração mostrando como implementar isso (supondo que exista algo assim!). Eu estou mais familiarizado com o IOS 12. em vez de 15. em qualquer lugar, mas também seria ótimo.

Suponho que essas pessoas estejam referenciando um tráfego correspondente de 5 classes configurado que seja uma das 5 classes padrão abaixo e processando o tráfego adequadamente;

  • Padrão DF
  • Encaminhamento expedido EF
  • VA Voice Admit
  • Encaminhamento garantido AF
  • Seletor de classe CS (para compatibilidade com versões anteriores)

Estou procurando um exemplo de configuração do IOS que corresponda a 5 (ou 7!) Classes de tráfego e, em seguida, aplique uma política apropriada ( entendo que este é um grande vago, operadores de rede diferentes podem querer que o tráfego seja tratado de maneira diferente, mas isso é puramente Quero ver 5 classes diferentes de tráfego sendo correspondidas e tratadas de maneira diferente ).

Nota

Eu ficaria realmente interessado em ver, por exemplo, como alguém configuraria essa política para, por exemplo, um link de 100 Mbps, para que, usando aritmética simples, eu pudesse escalá-lo para 1Gbps ou 10Mbps. Suponho que, para que isso seja eficaz, todo esse esquema de QoS precisaria reservar espaço em buffer ou alocar espaço em bucket, em vez de usar o policiamento para limitar a largura de banda, por exemplo? Suponho que isso ocorre porque você não sabe quanta largura de banda de cada vez haverá voz, vídeo, dados ou P2P / Torrents, etc.

Respostas:


17

A Cisco possui algo que eles chamam de Cisco Validated Designs (CVD). Estes são projetos de rede de diferentes perspectivas, como QoS, alta disponibilidade, WAN, etc, que a Cisco recomenda e testou.

Para QoS, eles têm três designs diferentes, com 4, 8 ou 12 classes, que podem ser vistos na figura abaixo.

Classes de QoS da Cisco

Começando com o modelo de 4 classes:

! This section defines the 4-Class class-maps 
! (three are explicitly defined and one is default)
Router(config)# class-map match-any REALTIME
Router(config-cmap)# match dscp ef
 ! Matches VoIP
Router(config-cmap)# match dscp cs5
 ! Matches Broadcast Video
Router(config-cmap)# match dscp cs4
 ! Matches Realtime-Interactive

Router(config)# class-map match-any CONTROL
Router(config-cmap)# match dscp cs6
 ! Matches Network-Control
Router(config-cmap)# match dscp cs3
 ! Matches Signaling (control-plane traffic for voice/video infrastructure)
Router(config-cmap)# match dscp cs2
 ! Matches Network Management

Router(config)# class-map match-any CRITICAL-DATA
Router(config-cmap)# match dscp af41 af42 af43
 ! Matches Multimedia Conferencing on AF4 
Router(config-cmap)# match dscp af31 af32 af33
 ! Matches Multimedia Streaming on AF3
Router(config-cmap)# match dscp af21 af22 af23
 ! Matches Transactional Data on AF2
Router(config-cmap)# match dscp af11 af12 af13
 ! Matches Bulk Data on AF1


! This section defines the 4-Class Policy-Map
Router(config)# policy-map WAN-EDGE-4-CLASS
Router(config-pmap)# class REALTIME
Router(config-pmap-c)# priority percent 33
 ! Provisions 33% LLQ for REALTIME class
Router(config-pmap-c)# class CONTROL
Router(config-pmap-c)#  bandwidth percent 7
 ! Provisions 7% CBWFQ for CONTROL class
Router(config-pmap-c)# class CRITICAL-DATA
Router(config-pmap-c)#  bandwidth percent 35
 ! Provisions 35% CBWFQ for CRITICAL-DATA class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on CRITICAL-DATA class
Router(config-pmap-c)#   random-detect dscp-based
 ! Enables DSCP-based WRED on CRITICAL-DATA class
Router(config-pmap-c)#   random-detect dscp af11 50 64
 ! Tunes WRED min and max drop-thresholds for AF11/10 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af12 45 64
 ! Tunes WRED min and max drop-thresholds for AF12/12 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af13 40 64
 ! Tunes WRED min and max drop-thresholds for AF13/14 to 40 and 64 packets
Router(config-pmap-c)#   random-detect dscp af21 50 64
 ! Tunes WRED min and max drop-thresholds for AF21/18 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af22 45 64
 ! Tunes WRED min and max drop-thresholds for AF22/20 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af23 40 64
 ! Tunes WRED min and max drop-thresholds for AF23/22 to 40 and 64 packets
Router(config-pmap-c)#   random-detect dscp af31 50 64
 ! Tunes WRED min and max drop-thresholds for AF31/26 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af32 45 64
 ! Tunes WRED min and max drop-thresholds for AF32/28 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af33 40 64
 ! Tunes WRED min and max drop-thresholds for AF33/30 to 40 and 64 packets
Router(config-pmap-c)#   random-detect dscp af41 50 64
 ! Tunes WRED min and max drop-thresholds for AF41/34 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af42 45 64
 ! Tunes WRED min and max drop-thresholds for AF42/36 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af43 40 64
 ! Tunes WRED min and max drop-thresholds for AF43/38 to 40 and 64 packets
Router(config-pmap-c)# class class-default
Router(config-pmap-c)#  bandwidth percent 25
 ! Provisions 25% CBWFQ for default (Best-Effort) class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on default (Best-Effort) class
Router(config-pmap-c)#  queue-limit 128 packets
 ! Expands queue-limit to 128 packets
Router(config-pmap-c)#   random-detect dscp-based
 ! Enables DSCP-based WRED on default (Best-Effort) class
Router(config-pmap-c)#   random-detect dscp default 100 128
 ! Tunes WRED min and max drop-thresholds for DF/0 to 100 and 128 packets
Router(config-pmap-c)#   random-detect dscp cs1 60 100
 ! Tunes WRED min and max drop-thresholds for CS1/8 to 60 and 100 packets

Como você pode ver, ele corresponde a diferentes valores de DSCP. O DSCP EF é geralmente usado para VoIP. Isso significa que seus pacotes já devem ter sido marcados o mais cedo possível em sua rede. Os valores da largura de banda são inseridos em porcentagem, o que significa que a política pode ser aplicada em diferentes interfaces de velocidade e ainda fornecer bons valores em comparação com a entrada deles em kbit / s. Em interfaces de velocidade muito alta como 10 Gbit, pode ser muito usar 7% para controlar o tráfego, já que isso seria 700 Mbit / s.

Os dados e o padrão de classe usam a fila justa, que é uma maneira de enfileirar pacotes com base no DSCP e no tamanho do pacote para fornecer enfileiramento justo, mesmo para fluxos de pacotes pequenos. Para poder usar isso, você precisa de uma imagem que suporte o HQ (Hierarchical Queing Framework), que é 12.4 (20) T ou mais recente.

A Detecção Precoce Aleatória Ponderada (WRED) também é aplicada para resolver problemas como a sincronização TCP, na qual os fluxos TCP aceleram e recuam ao mesmo tempo.

Então você tem o modelo de 8 classes.

! This section defines the 8-Class class-maps 
! (seven are explicitly defined and one is default)
Router(config)# class-map match-all VOICE
Router(config-cmap)# match dscp ef
 ! Matches VoIP

Router(config)# class-map match-any INTERACTIVE-VIDEO
Router(config-cmap)# match dscp cs5
 ! Matches Broadcast Video
Router(config-cmap)# match dscp cs4
 ! Matches Realtime-Interactive
Router(config)# class-map match-any NETWORK-CONTROL
Router(config-cmap)# match dscp cs6
 ! Matches Network Control
Router(config-cmap)# match dscp cs2
 ! Matches Network Management

Router(config)# class-map match-all SIGNALING
Router(config-cmap)# match dscp cs3
 ! Matches Signaling

Router(config)# class-map match-all MULTIMEDIA-STREAMING
Router(config-cmap)# match dscp af31 af32 af33
 ! Matches Multimedia-Streaming on AF3

Router(config)# class-map match-any CRITICAL-DATA
Router(config-cmap)# match dscp af41 af42 af43
 ! Matches Multimedia-Conferencing on AF4
Router(config-cmap)# match dscp af21 af22 af23
 ! Matches Transactional-Data on AF2
Router(config-cmap)# match dscp af11 af12 af13
 ! Matches Bulk-Data on AF1

Router(config)# class-map match-all SCAVENGER
Router(config-cmap)# match dscp cs1
 ! Matches Scavenger


! This section configures the 8-class policy-map
Router(config)# policy-map WAN-EDGE-8-CLASS
Router(config-pmap)# class VOICE
Router(config-pmap-c)#  priority percent 10
 ! Provisions 10% LLQ for VOICE class (dual LLQ-policy)
Router(config-pmap-c)# class INTERACTIVE-VIDEO
Router(config-pmap-c)#  priority percent 23
 ! Provisions 23% LLQ for INTERACTIVE-VIDEO class (dual-LLQ policy)
Router(config-pmap-c)# class NETWORK-CONTROL
Router(config-pmap-c)#  bandwidth percent 5
 ! Provisions 5% CBWFQ for NETWORK-CONTROL class
Router(config-pmap-c)# class SIGNALING
Router(config-pmap-c)#  bandwidth percent 2
 ! Provisions 2% CBWFQ for SIGNALING class
Router(config-pmap-c)# class MULTIMEDIA-STREAMING
Router(config-pmap-c)#  bandwidth percent 10
 ! Provisions 10% CBWFQ for MULTIMEDIA-STREAMING class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on MULTIMEDIA-STREAMING class
Router(config-pmap-c)#   random-detect dscp-based
 ! Enables DSCP-based WRED on MULTIMEDIA-STREAMING class
Router(config-pmap-c)#   random-detect dscp af31 50 64
 ! Tunes WRED min and max drop-thresholds for AF31/26 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af32 45 64
 ! Tunes WRED min and max drop-thresholds for AF32/28 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af33 40 64
 ! Tunes WRED min and max drop-thresholds for AF33/30 to 40 and 64 packets
Router(config-pmap-c)# class CRITICAL-DATA
Router(config-pmap-c)#  bandwidth percent 24
 ! Provisions 24% CBWFQ for CRITICAL-DATA class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on CRITICAL-DATA class
Router(config-pmap-c)#   random-detect dscp-based
 ! Enables DSCP-based WRED on CRITICAL-DATA class


Router(config-pmap-c)#   random-detect dscp af11 50 64
 ! Tunes WRED min and max drop-thresholds for AF11/10 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af12 45 64
 ! Tunes WRED min and max drop-thresholds for AF12/12 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af13 40 64
 ! Tunes WRED min and max drop-thresholds for AF13/14 to 40 and 64 packets
Router(config-pmap-c)#   random-detect dscp af21 50 64
 ! Tunes WRED min and max drop-thresholds for AF21/18 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af22 45 64
 ! Tunes WRED min and max drop-thresholds for AF22/20 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af23 40 64
 ! Tunes WRED min and max drop-thresholds for AF23/22 to 40 and 64 packets
Router(config-pmap-c)#   random-detect dscp af41 50 64
 ! Tunes WRED min and max drop-thresholds for AF41/34 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af42 45 64
 ! Tunes WRED min and max drop-thresholds for AF42/36 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af43 40 64
 ! Tunes WRED min and max drop-thresholds for AF43/38 to 40 and 64 packets
Router(config-pmap-c)# class SCAVENGER
Router(config-pmap-c)#  bandwidth percent 1
 ! Constrains Scavenger class to 1% CBWFQ
Router(config-pmap-c)# class class-default
Router(config-pmap-c)#  bandwidth percent 25
 ! Provisions 25% CBWFQ for default (Best-Effort) class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on default (Best-Effort) class
Router(config-pmap-c)#  queue-limit 128 packets
 ! Expands queue-limit to 128 packets
Router(config-pmap-c)#   random-detect dscp-based
 ! Enables DSCP-based WRED on default (Best-Effort) class
Router(config-pmap-c)#   random-detect dscp default 100 128
 ! Tunes WRED min and max drop-thresholds for DF/0 to 100 and 128 packets

Essa política é mais granular para aplicativos em tempo real, como vídeo, streaming e sinalização para esses protocolos.

Finalmente, este é o modelo de 12 classes.

! This section configures the class-maps
! (eleven class maps are explicitly defined and one is default)
Router(config)# class-map match-all VOICE
Router(config-cmap)# match dscp ef
 ! Matches VoIP

Router(config)# class-map match-all BROADCAST-VIDEO
Router(config-cmap)# match dscp cs5
 ! Matches Broadcast Video

Router(config)# class-map match-all REALTIME-INTERACTIVE
Router(config-cmap)#  match dscp cs4
 ! Matches Realtime-Interactive

Router(config)# class-map match-all NETWORK-CONTROL
Router(config-cmap)# match dscp cs6
 ! Matches Network Control

Router(config)# class-map match-all SIGNALING
Router(config-cmap)# match dscp cs3
 ! Matches Signaling

Router(config)# class-map match-all NETWORK-MANAGEMENT
Router(config-cmap)# match dscp cs2
 ! Matches Network Management

Router(config)# class-map match-any MULTIMEDIA-CONFERENCING
Router(config-cmap)# match dscp af41
Router(config-cmap)# match dscp af42
Router(config-cmap)# match dscp af43
 ! Matches Multimedia-Conferencing
 ! One match statement per Drop Precedence increases visibility

Router(config)# class-map match-any MULTIMEDIA-STREAMING
Router(config-cmap)# match dscp af31
Router(config-cmap)# match dscp af32
Router(config-cmap)# match dscp af33
 ! Matches Multimedia-Streaming
 ! One match statement per Drop Precedence increases visibility

Router(config)# class-map match-any TRANSACTIONAL-DATA
Router(config-cmap)# match dscp af21
Router(config-cmap)# match dscp af22
Router(config-cmap)# match dscp af23
 ! Matches Transactional-Data
 ! One match statement per Drop Precedence increases visibility

Router(config)# class-map match-any BULK-DATA
Router(config-cmap)# match dscp af11
Router(config-cmap)# match dscp af12
Router(config-cmap)# match dscp af13
 ! Matches Bulk-Data
 ! One match statement per Drop Precedence increases visibility

Router(config)# class-map match-all SCAVENGER
Router(config-cmap)# match dscp cs1
 ! Matches Scavenger


! This section configures the 12-Class policy-map
Router(config)# policy-map WAN-EDGE-12-CLASS
Router(config-pmap)# class VOICE
Router(config-pmap-c)#  priority percent 10
 ! Provisions 10% LLQ to VOICE class (multi-LLQ policy)
Router(config-pmap-c)# class BROADCAST-VIDEO
Router(config-pmap-c)#  priority percent 10
 ! Provisions 10% LLQ to BROADCAST-VIDEO class (multi-LLQ policy)
Router(config-pmap-c)# class REALTIME-INTERACTIVE
Router(config-pmap-c)#  priority percent 13
! Provisions 13% LLQ to REALTIME-INTERACTIVE class (multi-LLQ policy)
Router(config-pmap-c)# class NETWORK-CONTROL
Router(config-pmap-c)#  bandwidth percent 2
 ! Provisions 2% CBWFQ to NETWORK-CONTROL class
Router(config-pmap-c)# class SIGNALING
Router(config-pmap-c)#  bandwidth percent 2
 ! Provisions 2% CBWFQ to SIGNALING class
Router(config-pmap-c)# class NETWORK-MANAGEMENT
Router(config-pmap-c)#  bandwidth percent 3
 ! Provisions 3% CBWFQ to NETWORK-MANAGEMENT class
Router(config-pmap-c)# class MULTIMEDIA-CONFERENCING
Router(config-pmap-c)#  bandwidth percent 10
 ! Provisions 10% CBWFQ to MULTIMEDIA-CONFERENCING class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on MULTIMEDIA-CONFERENCING class
Router(config-pmap-c)#   random-detect dscp-based
 ! Enables DSCP-based WRED on MULTIMEDIA-CONFERENCING class
Router(config-pmap-c)#   random-detect dscp af41 50 64
 ! Tunes WRED min and max drop-thresholds for AF41/34 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af42 45 64
 ! Tunes WRED min and max drop-thresholds for AF42/36 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af43 40 64
 ! Tunes WRED min and max drop-thresholds for AF43/38 to 40 and 64 packets
Router(config-pmap-c)# class MULTIMEDIA-STREAMING
Router(config-pmap-c)#  bandwidth percent 10
 ! Provisions 10% CBWFQ to MULTIMEDIA-STREAMING class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on MULTIMEDIA-STREAMING class
Router(config-pmap-c)#   random-detect dscp-based
 ! Enables DSCP-based WRED on MULTIMEDIA-STREAMING class
Router(config-pmap-c)#   random-detect dscp af31 50 64
 ! Tunes WRED min and max drop-thresholds for AF31/26 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af32 45 64
 ! Tunes WRED min and max drop-thresholds for AF32/28 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af33 40 64
 ! Tunes WRED min and max drop-thresholds for AF33/30 to 40 and 64 packets
Router(config-pmap-c)# class TRANSACTIONAL-DATA
Router(config-pmap-c)#  bandwidth percent 10
 ! Provisions 10% CBWFQ to TRANSACTIONAL-DATA class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on TRANSACTIONAL-DATA class
Router(config-pmap-c)#   random-detect dscp-based
 ! Enables DSCP-based WRED on TRANSACTIONAL-DATA class
Router(config-pmap-c)#   random-detect dscp af21 50 64
 ! Tunes WRED min and max drop-thresholds for AF21/18 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af22 45 64
 ! Tunes WRED min and max drop-thresholds for AF22/20 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af23 40 64
 ! Tunes WRED min and max drop-thresholds for AF23/22 to 40 and 64 packets
Router(config-pmap-c)# class BULK-DATA
Router(config-pmap-c)#  bandwidth percent 4
 ! Provisions 4% CBWFQ to BULK-DATA class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on BULK-DATA class
Router(config-pmap-c)#   random-detect dscp-based
! Enables DSCP-based WRED on BULK-DATA class
Router(config-pmap-c)#   random-detect dscp af11 50 64
 ! Tunes WRED min and max drop-thresholds for AF11/10 to 50 and 64 packets
Router(config-pmap-c)#   random-detect dscp af12 45 64
 ! Tunes WRED min and max drop-thresholds for AF12/12 to 45 and 64 packets
Router(config-pmap-c)#   random-detect dscp af13 40 64
 ! Tunes WRED min and max drop-thresholds for AF13/14 to 40 and 64 packets
Router(config-pmap-c)# class SCAVENGER
Router(config-pmap-c)#  bandwidth percent 1
 ! Constrains Scavenger to 1% CBWFQ
Router(config-pmap-c)# class class-default
Router(config-pmap-c)#  bandwidth percent 25
 ! Provisions 25% CBWFQ for default (Best-Effort) class
Router(config-pmap-c)#  fair-queue
 ! Enables fair-queuing pre-sorter on default (Best-Effort) class
Router(config-pmap-c)#  queue-limit 128 packets
 ! Expands queue-limit to 128 packets
Router(config-pmap-c)#   random-detect dscp-based
 ! Enables DSCP-based WRED on default (Best-Effort) class
Router(config-pmap-c)#   random-detect dscp default 100 128
 ! Tunes WRED min and max drop-thresholds for DF/0 to 100 and 128 packets

Essa política possui ainda mais classes para tráfego interativo e também mais classes para diferentes tipos de dados e uma classe de gerenciamento.

Finalmente, você deve aplicar a política a uma interface como esta.

saída da política de serviço int gix / x CLASSE WAN-EDGE-12

Aqui está um link para WAN QoS CVD.

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