No Walter, that's not a dumb question. There may be different explanations to the term "bounce". To me, it simply means to "remove from service, then restore back to service". Actually, you are "bouncing" the entire PRI, because the 23 B-Channels must be removed from service first, before the D-Channel can be removed/restored. You would then put the B-Channels back in service. You're basically "bumping, or bouncing" the PRI. On rare occasions, this "bouncing" is requested in attempts to possibly clear any synchronization issues, timing, etc.