1. BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS TRAFFIC-DRIVEN OPTIMIZATION OF ROUTING FOR METROPOLITAN ETHERNET NETWORKS András Kern, Tibor Cinkler, István Moldován

2. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 20062 » Ethernet is the most dominating LAN technology » Cheap equipment + high speed (up to 10 Gbps) Ethernet in Metro Access Networks » Introduce Ethernet into the Metro network (Metro Ethernet Forum): » consistent network platform » Ethernet should be Carrier Grade: » Traffic separation » QoS » Operation, Administration Management » Reliability » Scalability

3. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 20063 Routing in Ethernet: Spanning Trees Protocols (STP) » MORE VLAN based spanning trees » Multiple spanning tree instances » Each tree runs a separate Rapid STP instance » 1 VLAN 1 tree » By default tree spanning is Topology-Driven: » Port costs based on topology and link capacities » Costs can be set manually (to obtain desired trees) » Spanning Trees form loop-free logical topologies » Their shape influenced by Port Costs » Provide restoration

4. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 20064 Resilience » MSTP supports restoration » Does NOT consider either QoS or bandwidth reqs. may harm them. » Protection at Ethernet level » Ethernet Protection Switch (EPS) » VLAN switching » 2 VLANs: one for working one for backup » After link failure switch to backup VLAN » Supports QoS and bandwidth reqs.!!!!

5. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 20065 Quality of Service » Priority based scheduling: » Lower priority traffic is not served until there is higher priority traffic in the queue. » To ensure low delay for each QoS class: amount of higher priority traffic should be limited for each link » For each QoS class » Global » Static » Predefined limit is given. » The method of how to determine these limits is out of scope.

6. BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS Traffic Driven Optimization Method

7. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 20067 Traffic Driven Optimization of Metro Ethernet » Layer 2 TE » optimal network utilization, allowing high bandwidth but no protection, » good throughput with dedicated protection switching » To reach it: » Span more tree instances, and » Assign the VLANs (traffic demands) to these trees » Optimization aim is to: » Minimize the network usage to maximize the throughput while » Neither QoS nor bandwidth are violated » We proposed ILP based method to solve this problem

8. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 20068 Resilience in Traffic Driven Metro Ethernet » Alternatives: » Counting on the repairing capability of RSTP » Protection based on VLAN switching » Two link disjoint VLANs for each demands » same capacity is dedicated at both VLANs » Only prioritized traffic is protected with VLAN switching » Backup capacity is dedicated for them » It can be shared with BE traffic!

9. BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS Performance of Traffic Driven Optimization

10. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 200610 Assumed Topology » The traffic flows from the ANs to the ENs » Root of Tree instances at ENs. Traffic Source Traffic Destinatio n

11. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 200611 Traffic model » 3 QoS + 1 best effort traffic class. » Between every access-edge node pair one aggregated demand for each TC » Throughput estimator parameter (Global traffic level) Class nameTraffic Class Ratio Platinum3% Gold13% Silver30% BE54% Demand sizes are based on: » Traffic Class Ratio » Global Traffic Level

12. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 200612 Achieved Throughput The throughput significantly increased! But why?

13. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 200613 Balancing the trees Topology Driven MSTPOptimized Tree instance Bottleneck!!!

14. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 200614 Resilience » Topology driven: » 100% resilience » Low throughput » Optimizing MSTP: » Using redundant links » Higher throughput but lower resilience » VLAN protection: » Decreased throughput » Higher resilience

15. BME - TMIT BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS World Telecommunications Congress 200615 Conclusion » QoS + Protection + TE » Can be realized using MSTP » But tree optimization is required » We presented an ILP model for » Optimization » QoS, capacity and protection constraints are fulfilled » Significantly increased throughput is realized » RSTP Restoration does not consider » VLAN switch based protection is proposed » Halves the throughput but considers QoS! » Selective protection is proposed » Tradeoff between throughput and protection

16. BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF TELECOMMUNICATIONS AND MEDIA INFORMATICS Thank You