© 2006 Cisco Systems, Inc. All rights reserved.ONT v1.04-1 Implement the DiffServ QoS Model Deploying End-to-End QoS. - презентация

1 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Implement the DiffServ QoS Model Deploying End-to-End QoS

2 © 2006 Cisco Systems, Inc. All rights reserved.ONT v QoS SLAs

3 © 2006 Cisco Systems, Inc. All rights reserved.ONT v QoS SLAs QoS SLAs provide contractual assurance for meeting the traffic QoS requirements. QoS SLAs typically provide contractual assurance for parameters such as: –Delay (fixed and variable) –Jitter –Packet loss –Throughput –Availability

4 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Enterprise Network with Traditional Layer 2 Service Provider sells customer a Layer 2 service Point-to-point SLA from the provider Enterprise WAN likely to get congested IP QoS required for voice, video, data integration Service provider not involved in IP QoS

5 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Enterprise Network with IP Service Customer buys Layer 3 service from provider Point-to-cloud SLA from provider for conforming traffic Enterprise WAN likely to get congested Service provider involved in IP QoS

6 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Know the SLA Offered by Your Service Provider SLA typically includes between three and five classes. Real-time traffic gets fixed bandwidth allocation. Data traffic gets variable bandwidth allocation with minimum guarantee.

7 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Typical SLA Requirements for Voice

8 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Deploying End-to-End QoS

9 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Deploying End-to-End QoS

10 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Deploying End-to-End QoS (Cont.)

11 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Enterprise Campus QoS Implementations

12 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Campus QoS General Guidelines Multiple queues are required on all interfaces to prevent transmit queue congestion and drops. Voice traffic should always go into the highest-priority queue. Trust the Cisco IP phone CoS setting but not the PC CoS setting. Classify and mark traffic as close to the source as possible. Use class-based policing to rate-limit certain unwanted excess traffic.

13 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Campus Access and Distribution Layer QoS Implementation

14 © 2006 Cisco Systems, Inc. All rights reserved.ONT v WAN Edge QoS Implementations

15 © 2006 Cisco Systems, Inc. All rights reserved.ONT v WAN Edge QoS Implementation

16 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Traffic Leaving Enterprise Network Output QoS policy on Customer Edge controlled by service provider. Service provider enforces SLA using the output QoS policy on Customer Edge. Output policy uses queuing, dropping, and possibly shaping. Elaborate traffic classification or mapping of existing markings. May require LFI or cRTP. Output QoS policy on Customer Edge not controlled by service provider. Service provider enforces SLA using input QoS policy on Provider Edge. Input policy uses policing and marking. Elaborate traffic classification or mapping of existing markings on Provider Edge.

17 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Traffic Leaving Enterprise Network (Cont.) Customer Edge Output Policy Classification, Marking, and Mapping LLQ WRED [Shaping] [LFI or cRTP] Provider Edge Input Policy Customer Edge Output Policy Provider Edge Input Policy Classification, Marking, and Mapping Policing

18 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Traffic Leaving Service Provider Network Service provider enforces SLA using the output QoS policy on Provider Edge. Output policy uses queuing, dropping, and, optionally, shaping. May require LFI or cRTP. No input QoS policy on Customer Edge needed. Service provider enforces SLA using the output QoS policy on Provider Edge. Output policy uses queuing, dropping, and, optionally, shaping. May require LFI or cRTP. Input QoS policy on Customer Edge irrelevant.

19 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Traffic Leaving Service Provider Network (Cont.) Customer Edge Input Policy Provider Edge Output Policy LLQ WRED [Shaping] [LFI or cRTP] Customer Edge Input Policy Provider Edge Output Policy LLQ WRED [Shaping] [LFI or cRTP]

20 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Managed Customer Edge with Three Service Classes: Example The service provider in this example is offering managed customer edge service with three service classes: –Real-time (VoIP, interactive video, call signaling): Maximum bandwidth guarantee, low latency, no loss –Critical data (routing, mission-critical data, transactional data, and network management): Minimum bandwidth guarantee, low loss –Best-effort: No guarantees (best effort) Most DiffServ deployments use a proportional differentiation model: –Rather than allocate absolute bandwidths to each class, service provider adjusts relative bandwidth ratios between classes to achieve SLA differentiation.

21 © 2006 Cisco Systems, Inc. All rights reserved.ONT v WAN Edge Design ClassParameters Real-time (VoIP)Packet marked EF class and sent to LLQ Maximum bandwidth = 35% of CIR, policed Excess dropped Real-time (call-signaling) VoIP signaling (5%) shares the LLQ with VoIP traffic Critical DataAllocated 40% of remaining bandwidth after LLQ has been serviced Exceeding or violating traffic re-marked WRED configured to optimize TCP throughput Best-effortBest-effort class sent to CBWFQ Allocated 23% of remaining bandwidth after LLQ has been serviced WRED configured to optimize TCP throughput ScavengerBest-effort class sent to CBWFQ Whatever is left = 2% of remaining bandwidth

22 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Customer Edge-to-Provider Edge QoS for Frame Relay Access Customer Edge Outbound

23 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Customer Edge-to-Provider Edge QoS for Frame Relay Access Customer Edge Outbound (Cont.)

24 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Customer Edge-to-Provider Edge QoS for Frame Relay Access Provider Edge Inbound

25 © 2006 Cisco Systems, Inc. All rights reserved.ONT v What Is CoPP?

26 © 2006 Cisco Systems, Inc. All rights reserved.ONT v What Is CoPP? The CoPP feature allows users to configure a QoS filter that manages the traffic flow of control plane packets to protect the control plane against DoS attacks. CoPP has been available since Cisco IOS Software Release 12.2(18)S.

27 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Cisco Router Planes A Cisco router is divided into four functional planes: –Data plane –Management plane –Control plane –Service plane Any service disruption to the route processor or the control and management planes can result in business-impacting network outages.

28 © 2006 Cisco Systems, Inc. All rights reserved.ONT v CoPP Deployment To deploy CoPP, take the following steps: 1. Define a packet classification criteria. 2. Define a service policy. 3. Enter control-plane configuration mode. 4. Apply QoS policy. Use MQC for configuring CoPP.

29 © 2006 Cisco Systems, Inc. All rights reserved.ONT v CoPP Example access-list 140 deny tcp host any eq telnet access-list 140 deny tcp host any eq telnet access-list 140 permit tcp any any eq telnet ! class-map telnet-class match access-group 140 ! policy-map control-plane-in class telnet-class police conform transmit exceed drop ! control-plane slot 1 service-policy input control-plane-in

30 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Summary An SLA stipulates the delivery and pricing of numerous service levels. SLAs cover an assortment of data services, such as Frame Relay, leased lines, Internet access, web hosting, and so on. There are QoS requirements for different traffic types. Both the enterprise and the service provider must implement the proper IP QoS mechanisms to provide end-to-end QoS. General guidelines for enterprise QoS implementations are as follows: –Use robust switching design. –Use buffer management. –Use multiple queues. –Ensure that voice traffic always gets the highest priority. –Trust the Cisco IP phone CoS setting. –Classify and mark traffic as close to the source as possible. –Use class-based policing.

31 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Summary (Cont.) On a Customer Edge-to-Provider Edge WAN link, LLQ or CBWFQ, traffic shaping, cRTP, and LFI are typically required. CoPP is a hardware-independent mechanism for defining and implementing sophisticated router protection schemes. CoPP is easily deployed by leveraging the existing MQC infrastructure.

32 © 2006 Cisco Systems, Inc. All rights reserved.ONT v