August 3-4, 2004 San Jose, CA Developing a Complete VoIP System Asif Naseem Senior Vice President & CTO GoAhead Software

August 3-4, 2004 San Jose, CA Key Drivers of IP Services Mobile IM PTT & PoC Voice over WiFi Converged Services

August 3-4, 2004 San Jose, CA Service Expectations On-Demand & Uninterrupted Integration of existing Internet Services & VoIP

August 3-4, 2004 San Jose, CA Opportunities Users ServiceProviders EquipmentProviders Converged services Low prices Differentiated services New business models Quick service deployment Network elements TEMs are faced with unprecedented time to market pressures

August 3-4, 2004 San Jose, CA TEMs’ Challenges Non-Integrated Platform Platform Hardware Customer Applications Application Servers Scripting Languages Security OA&M Dev Tools RDBMS Test Tools Protocol Stacks Storage Mgmt. In-core Database Embedded Sys. Mgmt. Distributed Messaging Availability Mgmt. Upgrade Mgmt Platform Mgmt Services Operating System System Management Interface Little integration with O/S or platform Requires significant Integration work Diverts focus & resources from application work Makes it hard to use new technologies Requires high levels of expertise

August 3-4, 2004 San Jose, CA TEM’s Challenges (Contd.) Long evaluation efforts for solution pieces Long development & integration cycles Price pressure High risk of missing deadlines or failure Need to focus on core applications Hiring not tracking business growth

August 3-4, 2004 San Jose, CA Platform Hardware – cPCI, ATCA Operating System - CGL COTS Middleware OtherMiddleware SystemManagementServices HighAvailabilityServicesDistributedMessagingServices In-Core Data Store Application Interface Platform Interface SystemModel Applications A Carrier Application Ready Platform Standards-based components Hardware Operating systems Platform and application interfaces Pre-integrated, pre-tested middleware Multi-protocol interoperability Focus energy on core applications

August 3-4, 2004 San Jose, CA System Design Approach Focus on application ready platform Specific focus on high availability A phased approach to system design

August 3-4, 2004 San Jose, CA Phased Approach System model Basic fault detection Cold-restart Managed redundancy Basic systems management Phase 1 Phase 1 Phase 2 Phase 2 Phase 3 Phase 3 Basic Availability Enhanced Availability Stateful Failover

August 3-4, 2004 San Jose, CA System Model CommsApps O/S 3 O/S 4 O/S 5 O/S 6 O/S 1 O/S 2 Host H/W 1 Host H/W 2 Line H/W 3 Line H/W 4 Line H/W 5 Line H/W 6 PS 3 PS 4 PS 5 Fans 1 Fans 2 Fans 3 Comms Apps App 1 App 2 App 3 App 4 App 5 App 6 Service 1 Phase 1 Phase 1 Managed Objects Attributes: health, operation, administrative status Methods: access/control, monitoring, configuration Dependency mapping Physical and logical dependencies “Follow-the-leader” Parent-Child, Child-Parent, and circular dependencies Service Groups Logical representation of redundant resources and service units Recovery policies: 2N, N+1, N+M, Active/Active Redundant Replicated to hot standby system Persisted and restored across system restart

August 3-4, 2004 San Jose, CA Fault Detection Basic timing checks Heartbeats to monitor state of application or process Script-based health checks if Heartbeat APIs are not available Frequency and structure of health checks should be configurable PID Table Scheduled Health Check App HA Middleware Phase 1 Phase 1

August 3-4, 2004 San Jose, CA Cold Restart Cold restart Large number of faults occur only under certain loading or timing circumstances Restarting a failed module usually returns system to a known healthy state Cold-restart is fault-agnostic Application state is not preserved Phase 1 Phase 1 HA Middleware AppService

August 3-4, 2004 San Jose, CA Managed Redundancy Initial System Model Services and apps Cluster nodes Node failure N+1 policy Periodic health check System model information available at the standby node Node failure notification can initialize standby applications and services Application or service failure Node fail-over to standby Automatic re-start of failed node Active HA Middleware App 1 Service 1 Standby HA Middleware App 2 Service 2 Phase 1 Phase 1

August 3-4, 2004 San Jose, CA Basic Systems Management Phase 1 Phase 1 Single management point for system/cluster Browser or remote access Capability to check sate of the managed objects Basic system information Access to database tables

August 3-4, 2004 San Jose, CA Phased Approach to HA Phase 1 Phase 1 Phase 2 Phase 2 Phase 3 Phase 3 Basic Availability Enhanced Availability Stateful Failover  Detect application faults  Cold-restart  Manage redundancy  Basic systems management State preservation Warm re-start Enhanced fault detection & correction Enhanced logging Enhanced system management

August 3-4, 2004 San Jose, CA State Preservation & Warm Re-Start Reliable data checkpointing Fast messaging service Efficient data store In-core Replicated to the standby Persisted Warm re-start Available state information used in recovery to a standby Phase 2 Phase 2 Active HA Middleware Active Application Standby HA Middleware Checkpoint messages Standby Application

August 3-4, 2004 San Jose, CA Enhanced Fault Detection More granular fault detection Includes subsystems Accelerates fault isolation Faster recovery actions Reduces impact failures have on higher-level components Phase 2 Phase 2

August 3-4, 2004 San Jose, CA Enhanced Logging & Reporting Invaluable for root cause analysis Used in conjunction with Availability management Fault detection Error logging Failure reporting Call home capability, etc. System management interfaces Browser-based console SNMP interface CLI Phase 2 Phase 2

August 3-4, 2004 San Jose, CA Phased Approach to HA  Basic timing & heartbeat for fault detection  Basic redundancy management  Cold re-start  Basic systems management  State preservation  Warm re-start  Enhanced fault detection & correction  Enhanced logging  Enhanced system management Real-time checkpointing Hot re-start Full fault management Complete systems management Provisioning Upgrading Phase 1 Phase 1 Phase 2 Phase 2 Phase 3 Phase 3 Basic Availability Enhanced Availability Stateful Fail-over

August 3-4, 2004 San Jose, CA Stateful Failover Phase 3 Phase 3 Real time checkpointing Real time state preservation High speed distributed messaging for state information communication Hot Restart Seamless fail-over with full state information Dynamic reconfiguration of system model Automatic fail-over of any managed object Hardware Software – application, process, etc. Sub-systems Active HA Middleware Standby HA Middleware Active Application Real time Checkpoint messages Standby Application

August 3-4, 2004 San Jose, CA Full Fault Management Phase 3 Phase 3 Fault management must implement Detection Diagnosis Isolation Recovery Repair

August 3-4, 2004 San Jose, CA Systems Management Phase 3 Phase 3 Full Systems Management Flexible interfaces Hot swap Field upgrade Rolling upgrade Provisioning Static Dynamic

August 3-4, 2004 San Jose, CA In Conclusion Developers of VoIP systems are well advised to consider: Pre-integrated and tested middleware Commercial off the shelf components Take a phased approach to system design Focus on core applications

August 3-4, 2004 San Jose, CA Contact Information Dr. Asif Naseem Senior Vice President & CTO, GoAhead Software