In the XCF Activity Report - Path Statistics shown in Figure 3, the column labeled “REQ OUT” indicates the total number of attempts made to send a message over the indicated outbound signaling path. Note that summing the “REQ OUT” for all paths leading to a system may not equal the total number of messages sent to that system as presented in the RMF™ XCF Activity Report - Usage by System, nor will it necessarily equal the sum of the messages sent to that system as presented in the RMF XCF Activity Report - Usage by Member. Often these differences occur because the data for the reports is collected at slightly different times. But it is also the case that there is a subtle difference between the counts in the path statistics report for outbound paths and the counts in the other reports. The path statistics report counts the number of attempts to send a message over a path. The other reports count the number of messages accepted by the signaling service for delivery.

When a signaling path suffers a failure (such as an I/O error), any messages that were not successfully transferred are re-sent on some alternate signaling path. The second attempt to send the message is counted in the path statistics report, but does not show up in the XCF usage reports because the message is accepted for delivery just once. Except for a delay in delivering the message, the re-send of a message is transparent to the message sender. Also, if signaling paths are started and stopped during the monitoring intervals, the path statistics report may not show those devices, hence the messages sent over those paths would not show up in the path statistics report. The XCF usage reports would, however, show those messages.