You can start with the below most basic parameters
Device Level
Availability
Reachability
CPU Utilization
MemoryUtilization
Buffer Misses and Failures
Power related metrics
Fan Status/failures
Interface Level
Utilization
UtilizationOut/In
%ErrorsOut/In
%DiscardsOut/In
There are many other important performance variables, but again it more depends on what your network team is interested in looking at . Its good to have a discussion with the network team on their points of interest