Has anyone seen incompatibility issues with Cisco ISR 4331 with NIM-1MFT-T1/E1 modules? My group has 2 out of 800 total
installations of the ISR 4331 where the NIM-1MFT-T1/E1 will not allow the router to come up to Line UP / Protocol UP on the Serial Interface. In one case it was a RX issue and remedied by adding a 100 foot cable between telco NIU and NIM. We suspect too hot of a signal level. In the other case, it looks to be a TX issue. Setting the cablelength long option to -7.5 db on the T1 controller will turn off T1 alarms but there is not enough error free data getting to PE to bring up the Line Protocol, which is Frame Relay. In both examples the T1 controller shows no alarms. However, looking at the log will show that the T1 controller is flapping.
Our HWIC-1DSU-T1 modules in our 1941 routers run on the same T1 circuit with no issues.
Any technical resources for issues on these NIMs is appreciated.
