SIP has become the protocol of choice in service delivery platforms for implementing and deploying value added services. Developers of such applications include independent software vendors (ISVs), vendors selling a complete software- and hardware- integrated solution and system integrators (SIs). Companies in this space have typically unmatched capabilities in the application and service delivery space but are challenged when required to bear the significant resource investment required for compliance with carrier grade requirements due to time-to-market considerations and R&D resource allocation.
Developers of application servers, conference bridges, messaging servers, IVRs and other value- added applications are looking for solutions that can be easily integrated with their applications for answering the following carrier grade requirements:
High Availability, Fail-Over and Disaster Recovery
For deployment of a value-added service applications within carrier or operator networks, vendors need to handle high availability and resilience features such as local and global server clustering, mid-call failure recovery and health monitoring of servers and services. Compliance with these requirements typically fall in the system space and out of the scope of the application itself. Current solutions available for solving these challenges are limited to non SIP-aware external solutions that don’t provide a comprehensive solution beyond the layer 4 scope.
Scalability and Performance
Large scale deployments require systems to scale as deployment increases in a “scale as you grow” approach with complete transparency from a carrier or user perspective. This approach requires both the option to add more servers to scale the system and to offload traffic between locations depending on peak time needs. Answering this need requires a SIP-aware solution that can handle session persistency based on varying SIP parameters as well as transport and security offload from application servers to accelerate traffic handling.
Security
Deploying the application in the network exposes it to security threats such as DoS/DDoS attacks, worms and other SIP vulnerabilities. Floods of unsolicited SIP messages can easily consume CPU resources of the SIP servers. Similarly, state management of UDP packet floods can hog bandwidth resources and degrade voice and video service quality. This challenge is typically handled by addition of a network edge component such as an SBC to the network or by extensive work of the vendor to protect its system. These solutions provide only a partial answer for this critical issue and SBCs are typically a target to such attacks.
Time-to-Market
Building a solution that solves challenges of high availability, resilience, scalability and security will usually result in a long development cycle which in turn causes delays in release of product to market. Since time-to-market is typically of essence it is not common that all these needs are answered within the application scope thus some challenges are not addressed or are addressed with a partial solution.
Flexibility
Applications in this group are deployed in many types of networks with varying topologies providing different services in each implementation. This in turn creates a need for flexible configuration of message routing and load balancing rules as well as a configurable fail-over architecture.