Signalling System Number 7 (SS7) – Facility Request to Pivot (FRP)
|Publication Date:||1 May 1999|
Scope, Purpose, and Application
The Facility Request to Pivot (FRP) network capability permits an ISUP-capable SS7 Signalling Point that has received a call from another ISUP capable node, and has determined that the call should be connected to a Destination node other than itself, to have the connection established from a node earlier in the call path. FRP functionality is shared between the Request and Pivot nodes. The FRP capability may be invoked by an end user service or other network capability on a per-call basis. The specific end-user service or other network capability that may invoke FRP is not within the scope of this network capability description. In particular, the service or network capability that invokes FRP at each node determines whether to request pivoting the call at a prior FRP-capable node, to release the call, or to progress the call forward. The service or network capability similarly determines whether to offer its node as a possible point for connection to a different destination, should a new destination be derived. The FRP capability is not visible to the end user, but does allow an end user service the option of invoking it. Thus, there is a "layering" of services and capabilities.
If the Pivot and Request nodes are in different networks, the transmission of information elements and related procedures defined in this document may require appropriate agreements between transmitting and receiving networks. These agreements are beyond the scope of this document.
This standard applies to the Integrated Services Digital Network (ISDN) User Part (ISUP) and is intended to supplement the signalling functions and call procedures described in ANSI T1.113. This standard should be used in conjunction with other American National Standards related to supplementary services and network capabilities for a complete understanding of the interactions between FRP and other services and network capabilities.