1. Build High-availability Real-time SigTran Applications with DDP --- An Architectural Overview (Motorola) Qiaobing Xie, Randy Stewart March, 2000

2. Objectives Fast, transparent fault tolerance at both link and session levels  Link level (SCTP) -- survive network failures  Session level (DDP) – survive process failures

3. DDP Highlights Location transparency and server pooling (2N, N+K, etc.) Load sharing mechanisms Plug-n-play, dynamic scalability No single point of failure

4. Client 1 Client 2 DDP System View ENRP Name-space Server Cloud Call Server Distrib. Bulletin Server Pool

5. Fault Tolerance Applications IP SCTP DDP ENRP SigTran Applications m.cast A Reference Model

6. The ENRP Server IP SCTP ENRP Server Process m.cast ENRP Entry lists in local memory local names, remote names, multicast groups, etc. To clients (name query, response, update) To peer ENRP servers (update, sync, audit)