Designing QoS © 2004 Cisco Systems, Inc. All rights reserved. Designing QoS for Enterprise Networks ARCH v1.27-1

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v Factors to Consider for QoS What is the problem you are trying to solve by implementing a QoS solution? Which model do you want to use to solve the problem stated in the first question? How do you want to solve the problem? Is one solution better than another in terms of costs?

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v Design Approach to Enabling QoS

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v QoS Design Guidelines for Data Classify data into relative-priority model with no more than four classes: Mission-critical Transactional Bulk Best-effort

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v QoS Design Guidelines for Voice One-way requirements: –Latency no more than 150 ms –Jitter no more than 30 ms –Loss no more than 1 percent 17 kbps to 106 kbps guaranteed priority bandwidth per call 150 bps (+ Layer 2 overhead) guaranteed bandwidth for voice control traffic per call

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v QoS Design Guidelines for Videoconferencing One-way requirements –Latency no more than 150 ms to 200 ms –Jitter no more than 30 ms –Loss no more than 1 percent Minimum priority bandwidth guarantee required is video stream plus 20 percent

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v QoS Tools Mapped to Design Requirements

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v QoS at the Building Access Submodule

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v QoS at the Building Distribution Submodule

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v QoS at the Campus Backbone Submodule High-speed queuing Intelligent dropping LLQ WRED to drop low priority as queues fill up

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v Example: QoS Implementation

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v Summary You must configure QoS features throughout a network to provide for end-to-end QoS delivery. The QoS implementation for a campus network differs at the Campus Backbone, Building Distribution, and Building Access submodules. Small, medium, and large enterprise QoS solutions encompass all features, based on the needs of the enterprise.

© 2004 Cisco Systems, Inc. All rights reserved. ARCH v Learning Activities Case Study: OCSIC Bottling Company –Develop a QoS design for WAN links –Develop a QoS design for the Campus Infrastructure module –Provide justification for each design decision OPNET IT Guru Simulation –View the instructor demonstration and consider the key design questions