Welltech SPCI2S Intel NetStructure SS7 Boards - Manual (Page 16)

SS7 Programmer’s Manual for SPCI2, SPCI4 and CPM8 Issue 2 Page 16
3. CONFIGURATION AND OPERATION
3.1 Overview
Prior to attempting software configuration the user should gain an appreciation of
the flexibility of the protocol stack, what run-time options exist and which
mechanisms are used to select particular features. This section gives an overview
of these options. The user should also read the
Software Environment
Programmer’s Manual, which describes the basic principles of modules and
message passing.
3.1.1 System Structure
The SS7 software running on the board communicates with an application running
on the main CPU of the host computer. The physical interface to the board uses the
PCI bus. All communication with the board is handled by a device driver and all
message passing to and from the board is managed by a process (ssd) which runs
on the host computer.
In addition to running the application on the host processor the user may,
depending on the size of the overall system and the network topology, elect to run
some of the SS7 protocol modules also on the host. In such cases the interface
between the application and the SS7 protocol software remains identical. This
allows for easy migration from a small system contained on a single board to a
large system distributed over many boards with minimal changes to the application.
The table below illustrates some possible practical system configurations for a
telephony system.
Small System Medium System Large System
Software running on
board MTP2
MTP3
ISUP / TUP MTP2
MTP3 MTP2
Software running on
Host CPU User Application ISUP / TUP
User Application MTP3
ISUP / TUP
User Application
Number of boards Single Single board with
signalling (although
additional boards may
be used to support
voice only) Multiple
Description Suitable for small
systems, supporting 1,
2, 3 or 4 signalling
links and up to 4096
voice circuits. Suitable for systems
with up to 4 signalling
links where more than
4096 voice circuits are
required. Suitable for systems
with more than 4
signalling links, and
systems that require
distribution of MTP
over multiple boards.