SIP Stack Implementations

The SIP stack, the core component of any SIP-based application, processes SIP messages and ensures proper communication flow. SIP stacks operate in three distinct modes: stateless, transaction-based (stateful), and dialog-based, each optimized for different use cases.

Stateless SIP processes each request and response independently, without storing session data. This approach minimizes memory usage and enhances scalability. Stateless SIP is ideal for high-throughput applications like SIP proxies that forward messages without tracking transactions. However, it does not handle retransmissions or message sequencing, which reduces its reliability.