This sets the timer started after the gateway sends its last forward register digit, within which it expects to receive the backward register answer signal, and per the MIB this is normally the same value as ccasRSTCompelledFwdToneOnTimer though some country variants set it differently. Because this timer can legitimately diverge from the compelled-tone timer depending on the R2 country variant in use, an admin migrating a profile between countries needs to verify this value explicitly rather than assuming it inherits correctly from the tone-on timer. A country variant that requires a longer post-digit wait than its own compelled-tone-on timer might set this to 4 seconds even though ccasRSTCompelledFwdToneOnTimer is set to 2 seconds, reflecting that specific national R2 practice.