I am using one T1 line for testing. I have tried it two different ways:
with a 1600/WIC at each end, and with a 1600/WIC at the remote end and the 2600/VWIC at the central site.
With a 1600 at each end, using the T1 WIC cards, the line works fine.
If I move the central site end to the VWIC on the 2600, both routers tell me
that the line is up but the line protocol is down. It looks like there is a
problem with the VWIC configuration. I have been through all of the Cisco
online documentation, but have not found any clue as to what might be wrong.
Per instructions from AT&T, I have set framing to esf and linecode to b8zs,
and have the central site routers set as clock source internal, and the
remote as clock source line.
While the configuration commands are different between the WIC and VWIC, I
think I have them set the same in all respects, but the WIC/1600 combination
works and the VWIC/2600 does not.
