Some gateways do not support ringback.
To reconfigure the gateway and protocols so that they support ringback, refer to this table:
26XX Foreign Exchange Office (FXO)
Media Gateway Control
WS-6608-T1(Catalyst 6K 8-port T1 PRI)
WS-6608-E1 (Catalyst 6K 8-port E1 PRI)
AT-2, 4, 8
For more information on resolving Cisco Customer Response Applications (CRA) and Customer Response Solutions (CRS), refer to these documents:
Voice applications (CRS, PA, CCM Plugins, CER, CCC, MeetingPlace, etc.)
Call connection (Connection quality: One-way audio, no busy tone, dropped calls, etc.)
IP phones and other clients (Client registration, faulty IP phone, etc.)
Call connection establishment
Call redirection (Transfer, hold, forward, conference)
Dropped or disconnected calls
IP phone faulty operation
Drops out, times out, flaps, toggles, hangs, gets stuck, locks up, loops, temporary pause, stops responding, cuts short, etc.
Nothing plays: Missing tone, music, greeting, prompt, message, announcement, etc.
Bad operational behavior
IP Contact Center (IPCC) Express (formerly IP ICD)
IP contact center (IPCC) express