Originally Posted by whipador

This may be more than what you want, but you might want to check it out.

[url="http://advanced.comms.agilent.com/dna/na/namain.html"]

[url="http://advanced.comms.agilent.com/dna/dnaplatform/dnamain.html"]

I used to be in the network testing business but have been out of it for at least 5 years. So here is some info that may no longer be up-to-date.

You say you have 70 sites. Does this mean you have 70 geographic locations with a single or multiple LAN at each site? How large is each LAN? Do you have multiple segments? What technologies are you using?

Depending on the above answers, here are some possible solutions.

1) Most switch/router manufacturers have software that you can use to pull the stats of the routers. The information is only as good as the diagnostics built into the switch/router. Usually this is no where as complete as a dedicated test solution but may be enough for your needs.

2) Test software that resides on specified computers that attach to each segment of each LAN. These computers must always be left on and connected to the LAN. This gives you visibility into each segment of your networks (remember that not all packets will flow through the router -- as a matter of fact, a well designed network will place all of the nodes that communicate often on the same segment -- that reduces the traffic that has to get through a router). However, most network interface cards will miss packets as the traffic increases. Since you likely have bursts of traffic (i.e. very high speed for a very short period of time), the NIC will miss some of it. If you are looking for trends, etc. this is no problem. If you are looking for a complete solution where you can troubleshoot thoroughly, then you need to get an embedded hardware solution.

3) Embedded hardware. "Probes" are put on the most important segments of the network. A centralized monitoring system will automatically report trends and send out alerts/alarms to the Network Administrator. Most systems will use a form of artificial intelligence to "learn" your network. The more traffic and the longer it is attached, the better it will be at finding problems before your users notice them. It will make suggestions as to how to improve the network and prevent problems. Of course, this is the most expensive solution and depending on your network could run from $30,000 to a million dollars. The Agilent solution above is this type of system.

All of the above is assuming that you are monitoring a LAN. If you are monitoring a WAN the technology changes quite a bit. Most network monitoring hardware-based solutions have options to monitor a wide variety of networks. The router based solutions would not.

Hope this is of some help. Like I said, I have been out of this business for at least 5 years so things have probably changed quite a bit.