Fig. 25. Centralized session initiation scheme.
To complete a centralized session initiation process over a packet-switched network (Fig. 25) SI server identifies technological addresses of interacting devices using results of protocol message comparison, creates a communication session identifier and sends it to client applications running on user terminals. Then, during a communication session, SI server manages a centralized packet switching.
The specific feature of this switching type is the fact that the softswitch exchanges both source and destination technological addresses of switched packets.
Fig. 26. Peer-to-peer session initiation scheme.
To complete a peer-to-peer session initiation process over a packet-switched network (Fig. 26), as in previous case, SI server identifies technological addresses of interacting devices and then sends a technological address of the destination device to the calling one.
Fig. 27 and Fig. 28 illustrate centralized and peer-to-peer session initiation schemes for accessing information resources.
Fig. 27. Centralized session initiation scheme for accessing an information resource.
A choice between centralized and peer-to-peer schemes depends on many various factors including a business model, network topology, performance and security issues, etc.
Fig. 28. Peer-to-peer session initiation scheme for accessing an information resource.
In both cases of a session initiation scheme for an information resource access, SI server practically replaces a DNS server and a domain network resource addressing. |
