Perf. Analysis on Carrier-grade networks

I have a customer with a requirement to do performance analysis, capacity
planning, network optimization, and network documentation on carrier-grade
networks. Very few of the tools I'm used to working with (NetMaker, Comnet,
etc.) can do this kind of analysis on hybrid voice/data networks.

Does anyone have any experience with any software packages that could
address one or more of the above requirements? The networks we need to
model consist of a mixture of TDM, FastPacket, and IP traffic running over
an eclectic mix of topologies, including T1, E1, FR, ATM (DS3), and OC-3
SONET. It would be helpful if the software could perform failure analysis
scenarios on selected components of the network.

Thanks in advance for your help.

Larry Deleski
Cisco Systems