Welltech Dialogic SS7 Protocols ISUP - Manual (Page 21)

Dialogic ® SS7 Protocols ISUP Programmer's Manual Issue 15
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5 Interface to MTP
The ISUP module interfaces with the Message Transfer Part (MTP) using the
following primitives, all of which are defined in ITU-T Recommendation
Q.704.
MTP-TRANSFER-REQ Transmit message to MTP
MTP-TRANSFER-IND Receive message from MTP
MTP-PAUSE Remote point code unavailable indication from MTP
MTP-RESUME Remote point code available indication from MTP
MTP-STATUS Signaling point congested or Remote user unavailable indication
from MTP
The message format used to convey these primitives is defined in the MTP3
Programmer's Manual.
The ISUP module is usually used in conjunction with the MTP module.
However, the use of primitives in accordance with Q.704 ensures that it can
also be integrated with other MTP implementations if required.
To provide further flexibility the ISUP module supports the use of both
T_FRAMEs and R_FRAMEs or the use of MSGs for MTP-TRANSFERs between
the ISUP and MTP.
T_FRAMES and R_FRAMES are most useful when the ISUP module is running
on the same processor as MTP, whilst MSGs are generally used when the
ISUP module is running on a different processor than the one used for the
MTP, or in conjunction with an MTP other than the Dialogic ® SS7 Protocols.
A module configuration option (ISPF_TFRM) allows the user to select between
sending T_FRAMEs or sending MSGs. Receipt of both R_FRAMEs and MSGs is
supported in either mode.