[c-nsp] Internet monitoring in case of general issues

[james list]

Many times we recognize issues on internet, customer asking why additional
delays are experienced, why it takes so long to access services, why "this
afternoon is slow", we notice fresh bgp updates, etc etc...

Everybody should know internet is cheap but unrealiable, customers many
times would like to save money with an ipsec vpn but then ask for
penalities if the service is not reachable, there is ddos opportunity etc
etc

The question: once you notice issues on internet and your upstreams are
fine, what instrument or service or commands or web site do you use to try
to find out where is the problem and who is experiencing the problem (ie a
tier1 carrier)?

Cheers
James