Abstract: A program is executed using a call stack and shadow stack. The call stack includes frames having respective return addresses. The frames may also store variables and/or parameters. The shadow stack stores duplicates of the return addresses in the call stack. The call stack and the shadow stack are maintained by, (i) each time a function is called, adding a corresponding stack frame to the call stack and adding a corresponding return address to the shadow stack, and (ii) each time a function is exited, removing a corresponding frame from the call stack and removing a corresponding return address from the shadow stack. A backtrace of the program's current call chain is generated by accessing the return addresses in the shadow stack. The outputted backtrace includes the return addresses from the shadow stack and/or information about the traced functions that is derived from the shadow stack's return addresses.

Abstract: A call routing system comprises a signaling processor with an internal cache memory. The signaling processor receives a signaling message and searches the cache memory with a called number to determine whether or not the called number has an associated location route number or if a query is required. If the query is required, the signaling processor transfers the query and receives a response that indicates whether or not the called number has the associated location route number. If the called number has the associated location route number, the signaling processor processes the location route number to select a connection. If the called number does not have the associated location route number, the signaling processor processes the called number to select the connection. If the response is received, the signaling processor updates the cache memory to indicate whether or not the called number has the associated location route number.

Abstract: A system and method for caching N00 information comprises an N00 cache that can be located in a signaling processor. The N00 cache is a memory cache that contains the N00 information, such as the N00 number and a destination number. The signaling processor receives and processes call signaling. The signaling processor accesses the N00 cache to determine if the destination number for the N00 number exists. The N00 cache returns the destination number if a match is found for the N00 number. If a match is not found, the signaling processor can be configured to query an N00 service control point (SCP).

Abstract: A system and method for caching local number portability (LNP) information comprises an LNP cache that can be located in a signaling processor. The LNP cache is a memory cache that contains the LNP information, such as the dialed number (DN) and the location routing number (LRN) for an associated DN. The signaling processor receives and processes call signaling. If the signaling processor determines that a DN may be assigned to a portable communication device, such as a portable signaling processor, then the signaling processor accesses the LNP cache to determine the LRN for the DN, if it exists. The LNP cache returns the LRN if a match is found for the DN and if the DN has a corresponding LRN. If a match is not found, the signaling processor can be configured to query an LNP service control point (SCP). Alternately, the LNP cache can be configured to include DNs that have a corresponding DN entry or a blank entry, but not an LRN entry, to signify that the DN is not ported.