For PeSit Transfer, how do Cycle Link and Cycle ID work?

Cycle ID and Cycle Link received in PeSit transfer notification allow Sentinel to establish links between transfers.

The Cycle ID is calculated locally with the PeSit protocol elements which are same for two transfer ends. So Cycle IDs obtained on 2 ends are identical and then for Sentinel there is only one transfer even notifications come from different sites.

The Cycle Link is calculated only on intermediate site for commuted transfer and sent to Sentinel for either "routed from" transfer and "routed to" one. Then Sentinel will link 2 transfers which have different Cycle IDs but the same Cycle Link.

Please see the following cases

Case 1:  SiteA -->(trans1) --> SiteB
- One set of notifications sent by Site A (to Sentinel) with "Cycle ID A" calculated on SiteA for trans1
- One set of notifications sent by Site B (to Sentinel) with "Cycle ID B' " calculated on SiteB for trans1
Because PeSit elements used in calculation are identical  "Cycle ID A" will equal to "Cycle ID B " (same Cycle ID). In this case 1, there is no calculation of Cycle Link.

Case2: SiteA -->(trans1) --> SiteB --> (trans2) --> SiteC
- One set of notifications sent by Site A (to Sentinel) with "Cycle ID A" calculated on SiteA for trans1
- One set of notifications sent by Site B (to Sentinel) with "Cycle ID A1 " and "Cycle Link B" calculated on SiteB for trans1
- One set of notifications sent by Site B (to Sentinel) with "Cycle ID C"  and "Cycle Link B"  calculated on SiteB for trans2
- One set of notifications sent by Site C (to Sentinel) with "Cycle ID C1 " calculated on SiteC for trans2
Because PeSit elements used in calculation are identical, "Cycle ID A" equals to "Cycle ID A1 ",  "Cycle ID C" equals to "Cycle ID C1 ". On intermediate siteB, the CycIe Link B is added for 2 transfers so that Sentinel can establish the link between 2 different Cycle IDs (Cycle ID A & Cycle ID C) by the identical Cycle Link (Cycle Link C).