Our 3845 ISR (12.4(15)T1)only has ISDN switch-type of "primary-ni", and our Unified Manager 6.0 only has NI2 option for ISDN switch-type. Our telco told us their switch is NI2, but our CM Express has been working for months with the gateway set as NI.
Will the ISDN switch type difference (ni/ni2) cause the gateway "endpoint" to not register properly?
No, it will not.
Beside the fact that NI and NI2 are interoperable, if you use MGCP, which switch type you have configured on the GW, is immaterial, except for SRST.
Hope this helps, please rate post if it does!