HI Karthik, [Pls Rate if Helps]
MRTG / Cacti is a Industry recommended Tool for Monitoring the Network Devices.
With this You can use RRD Tool for Database.
This Tools runs on Windows,Linux & Solaris. You need Apache, Perl, MRTG & RRD for Setup.
You can poll the Network Devices using SNMP Protocols & you need to enable the SNMP Traps in the Cisco Router / Switch.
You can generate graphs for Line Load, Packet Loss, CRC errors, etc., depends upon your requirement you can configure the same.
MRTG:
http://oss.oetiker.ch/mrtg/
http://oss.oetiker.ch/mrtg/doc/index.en.html
Cacti:
http://cacti.net/
RRD:
http://oss.oetiker.ch/rrdtool/
PLS RATE if Helps
Best Regards,
Guru Prasad R