Line Incompatibility Issues, ISR 4000 with NIM-1MFT-T1

[00u14js7kunnh7NNv5d7]

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.

[Nithin Eluvathingal]

I have almost 12 sites running on ISR 4K with NIM t/e1. no where I faced  such  issue. can you share the config.

[00u14js7kunnh7NNv5d7]

I can share only applicable parts of the config:

card type t1 0 2

controller T1 0/2/0
framing esf
linecode b8zs
cablelength long 0db
channel-group 0 timeslots 1-24

interface Serial0/2/0:0
bandwidth 1536
no ip address
encapsulation frame-relay IETF
frame-relay lmi-type ansi
no shut

[Nithin Eluvathingal]

I use  this for voice communication. I never used cable length command. And I don't see any network clock commands for

synchronization.

Since you use it for data, Better post this in network community. 

[Roger Kallberg]

Like @Nithin Eluvathingal we use these type of routers for voice services, we have around 80 or so of them and have not seen the issue you describe. I would agree with the recommendation to post your question in the network part of the community as it’s not related to Unified Communication.