Intelligent Network - Variants

Variants

The core CS-1 specifications were adopted and extended by other standards bodies. European flavours were developed by ETSI, American flavours were developed by ANSI and Japanese variants also exist. The main reasons for producing variants in each region was to ensure interoperability between equipment manufactured and deployed locally (for example different versions of the underlying SS7 protocols exist between the regions).

New functionality was also added which meant that variants diverged from each other and the main ITU-T standard. The biggest variant was called Customised Applications for Mobile networks Enhanced Logic, or CAMEL for short. This allowed for extensions to be made for the mobile phone environment, and allowed mobile phone operators to offer the same IN services to subscribers while they are roaming as they receive in the home network.

CAMEL has become a major standard in its own right and is currently maintained by 3GPP. The last major release of the standard was CAMEL phase 4. It is the only IN standard currently being actively worked on.

The Advanced Intelligent Network (AIN) is the variant of Intelligent Network developed for North America by Bellcore (now Telcordia). The standardization of the AIN was performed by Bellcore (now Telcordia Technologies) on behalf of the major US operators. The original goal of AIN was AIN 1.0, which was specified in the early 1990s (AIN Release 1, Bellcore SR-NWT-002247, 1993). AIN 1.0 proved technically infeasible to implement, which led to the definition of simplified AIN 0.1 and AIN 0.2 specifications. In North America, Telcordia SR-3511 (originally known as TA-1129+) and GR-1129-CORE protocols are used to link switches with the IN systems such as Service Control Points (SCPs) or Service Nodes. SR-3511 details a TCP/IP-based protocol which directly connects the SCP and Service Node. GR-1129-CORE provides generic requirements for an ISDN based protocol which connects the SCP to the Service Node via the SSP.