My Customer have a solution IP Telephony. The Customer is working with MGCP in CallManager Version 5.1. The carrier set Framing for CRC4, but when I set CRC4 and Gateway and CCM the E1 was down, but when I set framing for no-crc4 the E1 was up and generate Slip Erros. Anyboldy any Idea what is occuring?
As Paolo said, slips errors may be due to lack of network-clock-participate and network-clock-select commands.
Now that you check with your Telco that framing is no-crc4, now check if you have network-clock-select and network-clock-participate in your configuration.
If not, please configure under global configuration mode:
Router(config)# network-clock-participate wic 0
Router(config)# network-clock-select 1 E1 0/0/0