I am aware of this issue with the VWIC-2MFT and similar 2 port NM-HD modules. The web page does not have a sample of a 2 port VWIC with 2 data T1s coming into same card.
We have 2 T1s part of a multilink frame relay bundle coming into a VWIC-2MFT. The second T1 is line clocking and first one is line primary. I expect slips to happen on 2nd port regardless due to design of the VWIC-2MFT hardware but cisco docs state the router can anticpate the controlled slips.
Now, for data T1s the controlled slips are not really noticabale to user. But if these were Voice T1s they would be.
Is there a reason why 2 data T1s aren't covered in that document? Many people are not aware of the clocking issues with these and I find several people buying 2 port VWICs to do data on them to get port density at a lower cost. Then the slips and clocking problems are a real bear to clean up at times afterwards.
But putting the above aside, the network-clock commands we put in above should not have caused the T1 to go down. I know they won't help in this situation but all we were trying to do was set a common clocking source for the router backplane/PLL.
