Softswitch lahir dari pengembangan teknologi jaringan data yang kini telah mendominasi. Pengembangan ini merupakan migrasi dari jaringan PSTN menuju NGN (Next Generation Network) yang berbasis data. Layanan telekomunikasi pada NGN (Next Generation Network) meliputi voice, data, dan multimedia.
Adapun arsitektur softswith, dapat dilihat pd gmbr dibwh :
1. Transport Plane :
Responsible transport of messages (call signaling, call and media setup, or media) across the VoIP network
The transport plane is further divided into three domains:
• IP Transport Domain :
• Interworking Domain;
• Non-IP Access Domain
a. IP Transport Domain
Provides the transport backbone and routing/ switching fabric for transporting packets across the VoIP network
b. Interworking Domain
• Domain are primarily responsible for the transformation of signaling or media received from external networks into a form that can be sent among the various entities in the VoIP network and vice versa.
• Consists of devices like :
• Signaling Gateways (signaling transport conversion between different transport layers),
• Media Gateways (media conversion between different transport networks and/or different media),
• Interworking Gateways (signaling interworking on the same transport layer but with different protocols).
c. Non-IP Access Domain
• Domain that applies to non-IP terminals and wireless radio networks that access the VoIP network.
• Consists of :
• Access Gateways or Residential Gateways for non-IP terminals or phones.
• ISDN terminals,
• Integrated Access Devices (IADs) for DSL networks
2. Call Control & Signaling Plane
• It controls the major elements of the VoIP network, especially in the Transport Plane
• Consists of devices like :
• Media Gateway Controller (a.k.a. Call Agent or Call Controller),
• Gatekeepers and LDAP servers
