This is the measured round-trip time, in hundredths of a second, between the last Accounting-Request the switch sent to this server and its matching response. A rising round-trip time specifically on the accounting path, while the authentication server's round-trip time stays normal, points to load or disk I/O problems on the accounting collector's database, since accounting servers typically do more write-heavy work than authentication servers. For example, a value climbing from 80 (0.8 seconds) to 4000 (40 seconds) over a billing period could coincide with an accounting database running out of disk space or hitting a write bottleneck.