MetaFrame in Practice: Design of Intelligent Network Services - Correct System Design: Recent Insights and Advances - page 382

SMP

Service
Administration

SCEP
Customer Service Control

Data Communication
Network

SCEP
Service Customisation

Service Management Point

Data
Transmission

Data Communication
Network (DCN)

SCEP Service Definition

SCP

Service
Control

Service Control Point

Signalling
Transfer

CCS No. 7

SSP

IP

Intelligent
Peripheral Service

Access

Service Switching Point

Telephone network/ISDN

(A-Party) (B-Party)

Fig. 2. Global Architecture of an Intelligent Network

formation (train schedules, stock quotes) under a unique number and against a
usage fee. To satisfy the growing expectations on IN services, a flexible Service
Denition Environment is a must. This need is independent of the current shift
of emphasis from IN solutions towards unied messaging approches comprising
also IP, GSM, satellite communication.
The underlying Intelligent Network Architecture (see Fig. 2) is composed
of several subsystems that cooperate to implement the intended functionality.
They form complex distributed systems , where central computers, databases, the
telephone network, and a huge number of peripherals must be coordinated un-
der real-time, availability, and performance constraints. This complex structure
makes modications and extensions dicult and error prone. In particular, the
design of new services must take into account requirements imposed by the un-
derlying intelligent network: e.g., system-dependent frame conditions must be
obeyed in order to guarantee reliable execution of the new services.
Therefore, the introduction of complex services like the ones mentioned above
typically still takes expert-years for development and testing. A good Service
Denition Environment is intended to support a reliable service development,