1 A Method to Manage the Corporate WAN Jim Martin Assistant Professor of Computer Science Clemson University

2 For a residential Internet access service, what is service quality? Service quality means that the service being delivered is meeting requirements. Your Home Computer Internet Access Network ISP’s Network

3 How would you assess service quality? –First, define appropriate performance metrics: What is a metric? –A quantity that is related to performance and reliability of a network. Examples: –Availability: Based on connection failures or service outages. –network performance: loss and latency to meet certain bounds. –Second, define what good performance is based on the metrics In other words, identify an assessment decision

4 Your Home Computer Internet Access Network Where can performance problems occur? The destination? The Internet ? The access network ? ISP’s Network The ISP ? Performance problems can exist anywhere….

5 Your Home Computer Internet Access Network What service quality can a residential user expect? End-to-end performance ??? ISP’s Network In this environment, there’s no point to offering an Internet access service with performance guarantees.

6 How about a corporate network? A market exists for end-to-end performance guarantees! What’s the difference from the residential scenario? No INTERNET!! Companies are willing to pay more for a more predictable service! Employees ISP Access Network Corporate Network (branch office) Corporate Network Private Network Interconnection done via a VPN service.

7 Why should an organization manage their WAN? Employees ISP Access Network Corporate Network (branch office) Corporate Network Two reasons: 1.To validate service provider supplied SLAs. 2.More importantly to determine if the WAN service is negatively impacting employee productivity. Employees require data and services located at the main corporate network

8 How should an organization manage their WAN? Employees ISP Access Network Corporate Network (branch office) Corporate Network Traditional approach to validate service levels and provisioning decisions based on ping-based metrics: Problem: it’s hard to correlate the metrics with end user’s quality of experience. Much easier with application level metrics. Ping-based active probe process at the service endpoints

9 What are the research issues? Develop ‘user oriented’ performance metrics and assessments. Develop an ‘organization oriented’ assessment decision. Employees ISP Access Network Corporate Network (branch office) Corporate Network Use application and service specific metrics to drive a policy based assessment decision. Monitor application (web, streaming, telephony) and service specific metrics at the service endpoints