Tracking Multi-Site Call Data Via ISCC
Multi-site calls are tracked using an intersite link, which enables you to connect the information regarding two calls that originated on two different sites.
Intersite link (IS link) data is stored in the G_IS_LINK and the G_IS_LINK_HISTORY tables. It enables ICON to link all multi-site calls, determine the correct TEvent sequence, and check whether a multi-site call is completed.
Determining the Correct Event Sequence
To track the order in which events come from SIP Server, ICON writes the SIP Server event sequence in the GSYS_EXT_VCH1 field in the G_IS_LINK table. This TEvent sequence can be the same value for different data source sessions (DSSs).
ICON also writes the value for LastTransferOrigDN from the TEvent into the GSYS_EXT_VCH2 field in the G_PARTY table and the value for LastTransferHomeLocation into the GSYS_EXT_VCH1 field in the G_PARTY table.
ICON populates the TEvent attribute values for the ENDPOINTDN in the GSYS_EXT_VCH2 field and LastTransferHomeLocation in the GSYS_EXT_VCH1 field in the G_PARTY table whenever SIP Server provides this information. As a result, in multi-site interactions, ICON stores the necessary data to link ISCC calls, provide the correct event sequence, and determine when the call is completed.
Determining When a Multi-Site Call is Completed
A multi-site call is considered to be completed when one of the following occurs:
- All IS links have a corresponding IS-Link from another site.
- An IS link has been opened to an unmonitored switch.
- The timeout for an IS link to arrive from another site has expired, and all corresponding Interaction Roots in the G_IR table are closed.
Post-Mortem IS_LINK Capability
Post-mortem IS links occur when the information about the external site to which a call was transferred arrives after the call left the switch and ICON deleted it. When ICON receives EventTransactionStatus with the iscc.is-link-creation.post-mortem attribute set to true, ICON creates records in the G_IS_LINK table. The timestamp of the event is recorded as the link creation time, although that might be several seconds after call deletion.
ICON creates the new record in the G_IS_LINK table even if the referenced call has not been recorded in IDB. As a result, IDB might store records in the G_IS_LINK table that do not have a matching record in the G_CALL table.
The post-mortem IS link functionality can handle even complex scenarios. For example, ICON can correctly link and sequence call records for a consultation call that is transferred to another site and, after the transfer is complete, is merged with the main call.