Configuration notes
The following information describes provisioning restrictions:
- If a card or MDA type is installed in a slot provisioned for a different type, the card does not initialize. 
- A card or MDA installed in an unprovisioned slot remains administratively and operationally down until the card type and MDA is specified. 
- Ports cannot be provisioned until the slot, card and MDA type are specified. 
- cHDLC does not support HDLC windowing features, nor other HDLC frame types such as S-frames. 
- cHDLC operates in the HDLC Asynchronous Balanced Mode (ABM) of operation. 
- APS configuration rules: - A physical port (either working or protection) must be shut down before it can be removed from an APS group port. 
- For a single-chassis APS group, a working port must be added first. Then a protection port can be added or removed at any time. 
- A protection port must be shut down before being removed from an APS group. 
- A path cannot be configured on a port before the port is added to an APS group. 
- A working port cannot be removed from an APS group until the APS port path is removed. 
- When ports are added to an APS group, all path-level configurations are available only on the APS port level and configuration on the physical member ports are blocked. 
- For APS-protected bundles, all members of a working bundle must reside on the working port of an APS group. Similarly all members of a protecting bundle must reside on the protecting circuit of that APS group.