You are here: CSP Developer’s Guide: Common Channel Signaling > 4 SS7 Call Control for ISUP > CIC Start-up Procedure
Overview
The CSP supports the Exchange Type A start-up procedure as defined by Q.767, Section 4.4.1. Type A does not send any messages at start-up, but responds to a GRS with a GRA, or an RSC with an RLC. As the default exchange type for the CSP is Type B, you must perform configuration steps to enable Type A.
Configuring Exchange Type
The exchange type is configurable with PPL Config Byte 60 of the SS7 ISUP SPRC component (0x13).
If the exchange type is set to Type B (0x01, the default), GRS/RSC is sent at start-up. If the Exchange Type is set to Type A (0x00), GRS/RSC is not sent at start-up.
Type B Procedure (Default)
The default exchange type for the CSP is Type B, which requires sending a GRS/RSC at start-up. The CSP waits for a remote GRA/RLC before bringing the CICs in service.
Type A Procedure
If the exchange type is set to Type A, GRS/RSC is not sent at start-up. Timer 4 of the L3P CIC component is initiated to wait for a remote GRS/RSC indication. The default timer value is 500 ms (5 s).
If the timer expires before GRS/RSC is received, the CICs are placed in service and a PPL event of 0x17 (No GRS/RSC Received, CICs In Service) is sent to the host. You can disable the sending of the PPL event to the host by changing PPL Config Byte 14 of the SS7 L3P CIC component (0x0F) to 0x00. (0x00 - Do Not Send PPL Event to Host; 0x01 - Send PPL Event to Host).