Traffic Engineering over Ethernet Bridged Networks

1. Traffic Engineering over Ethernet Bridged Networks Benchmarking Carrier Ethernet Technologies Session MII.3 Krakow, Poland - April 30, 2008 Rémi Clavier - Orange Labs

2. MSTP generalities • MSTP: a native powerful control plane for Ethernet bridging • bring traffic load balancing • Instantiate up to 64 trees • enhance the resiliency of the network • increase the flexibility of the administration of the network • hierarchy with "Region" concept • But with some drawbacks • MSTP doesn't improve RSTP switching time • MSTP tuning can become a puzzle to configure, • except the "plug and play" use (with the poor performances of RSTP), • Specific tools may strongly help the operator • Analyze input data • Network properties, traffic assumptions, service change impacts • Optimize the network • Compute and download "good" MSTP parameters

3. Traffic Engineering in a Bridged Network • Analyze: • A set of parameters gives a unique and deterministic topology • A given topology implies the paths used by services • For a set of services and a given topology it's easy to compute • if services are "End To End" connected • the load used by each Link • the load used by each Bridge • Provisioning: • A resource is provisioned if bandwidth is available • the bandwidth is available if the load of each link used is sufficient enough • It's easy to determine if addition of a new service will overload some links • MSTP allows load balancing over different resources • Resiliency • MSTP automatically computes and applies a new active topology if resources fail • All characteristics of this new topology are deterministic and may be computed • The switching time depends on the network complexity • MTSP works in a revertive restoration mode

4. Topology And Physical resources Converge the Network and Analyze Loads & usages Textual and Graphical Reports Region and xSTI definition Services Functional description of the "analysing tool"

5. Functional description of the "optimization tool" • The MSTP Control Plane is used in a native way • No changes on protocol • No change on BPDUs • No change of interaction between Control Plane and Data Plane • An efficient optimization because • runs at the Management Layer • Is centralized • Gives to the MSTP Control Plane • A full set of parameters (for each bridge, for each port) • A suggested VLAN Mapping • And various reports to the operator • From • The Physical Network • The Traffic Matrix • The type of optimization profile (user defined)

6. Functional description Topology And Physical resources Converge the Network and Analyze Loads & usages Textual and Graphical Reports Region and xSTI definition xSTP Parameters VLAN mapping Services Optimization process

7. Case study: ADSL collect - Topology

8. Case study: ADSL collect -Traffic • P2P • TV Diffusion

9. Case study: ADSL collect - Results No Link Over Loaded One Link Over Loaded Same number of Links Used 18/45 Links Used Better repartition of Traffic Load Balancing efficiency(27/45 links used)

10. Thanks for your attention