Disabling T3 C-Bit Parity Mode

C-bit parity mode controls the type of framing that is present on the transmitted T3 signal. When C-bit parity mode is enabled, the C-bit positions are used for the FEBE, FEAC, terminal data link, path parity, and mode indicator bits, as defined in ANSI T1.107a-1989. When C-bit parity mode is disabled, the basic T3 framing mode (M13) is used.

By default, C-bit parity mode is enabled. To disable C-bit parity mode and use M13 framing for your T3 link, include the no-cbit-parity statement at the [edit interfaces interface-name t3-options] hierarchy level:

Note: For ATM and ATM2 IQ2 and IQ2-E interfaces, M23 framing is used when the no-cbit-parity statement is included. For all other interfaces, M13 framing is used when the no-cbit-parity statement is included.

To return to the default, enabling C-bit parity mode, delete the no-cbit-parity statement from the configuration:

To explicitly enable C-bit parity mode, include the cbit-parity statement at the [edit interfaces interface-name t3-options] hierarchy level: