EIR Protocol

Messages for Local Subsystems

The message arrives at the EIR subsystem as Rt-on-SSN or Rt-on-GT. If the message arrives as Rt-on-SSN, it must contain either the DSR true point code or the EIR capability point code in the DPC field of the message, and the DSR EIR subsystem number in the Called Party Subsystem field of the message. If the EIR query has DSR capability point code for the DPC, then DSR processes the message, but it is not able to divert this message in the event of subsystem failure.

If a message arrives at the EIR subsystem as Rt-on-GT, it should also contain a service selector that translates to the EIR subsystem. These messages also contain one of the DSR capability point codes in the DPC field. DSR also processes the message if it has the DSR true point code for the DPC, but it is not able to divert these messages in the event of subsystem failure.

SCCP Management to Support EIR

vSTP does not support a mated subsystem, hence, in case of SSN failure or a routing failure, messages are not routed to the mated node.

vSTP-MP can receive messages from a network with a CdPA routing indicator of route-on-gt and DPC is TPC in these situations:

• If a message has the subsystem (SSN) present and the SSN value is from EIR, then the message is sent for EIR processing.
• If message does not have the SSN or the SSN is not from EIR, then the SCCP layer performs normal GTT routing.

Note:

The SSN status management and network management messages, for example, SSP and UPU, do not support EIR; however, if the remote node sends an SST message, then SCCP handles the message.