I looked up iperf and like what I see. A simple lightweight tool for windows, linux, and android. I will plan on trying this out soon, seems like a great tool. From what I can tell though it seems to primarily measure throughput and quality, but doesn't tell exactly where the bottleneck is (unsure if this is possible though).
As far as a network map, its a pretty simple typical home setup. Router is a Buffalo (I believe wrt54g) flashed with Tomato, although I am already replacing this very soon with a much more powerful (cpu / ram wise), wireless n, gigabit router, as I suspect its the weak point, and I sometimes have to reboot it. Then there are a small number of laptops, phones, IP cameras hooked up. 4 devices are wired using the router ports, rest wireless.
I'm not yet familiar with SNTP traps, netflow, or PRTG. Rather than ask a ton of questions on here, I'll plan to set aside some google/youtube time later this weekend to try to learn about them. How would I know if my equipment is compatible? Can they actually identify the bottleneck? Like trace the packet through its journey across the lan, and find out where it slows down, such as the router, the wireless connection, etc?
SNMP (Simple Network Management Protocol) is used for monitoring, and can be configured to poll interfaces/devices at a given rate, to see what's most active, what's down, etc...
Netflow may only show up on the larger equipment, but it's extremely easy to see which stations are talking, what protocols are they using, who's the most active and consuming the most bandwidth. PRTG is just a tool that takes those stats, and presents them in nice, easy to read charts
. It's paid software out of germany, but there is a trial version available. I prefer it to costlier solutions, like Solarwinds.
If it SNMP and Netflow aren't mentioned in the the manual/guides for your gear (or Tomato), they probably don't support it.
Do you have logging enabled on the Buffalo? That might help you pinpoint issues (speed/duplex mismatches, incorrectly configured NAT Overload, DDoS attack attempts might show up there). Does the Buffalo support traffic monitoring? If you're going to get a gigabit router, make sure you're using UTP cable that supports gigabit speeds to any end devices that will be wired. Cat5e and Cat6 cable will work fine.
I haven't used their gear, other than Wireless AP/Bridge Repeaters, but RouterBOARD makes a reasonably priced Multi-layer gigabit switch with built-in 802.11n radios
for $209 MSRP. Each switchport is gigabit, and can be changed to routed ports, as needed.
Kind like my Cisco 3550. I can turn any of the 24 ports into either a switchport or a routed port (supporting all the usual routing protocols), and I can send power out any port, to provide Power over Ethernet (802.3af, NOT the new 802.3at) for Cisco IP Phones, or certain models of Cisco Access Points. Plus all the fancy netflow, CEF (for route once, switch many), VLANs, QoS, traffic shaping, and other neat features. You can even turn the Buffalo into a transparent bridge, and let the 3550 handle all the PPPoE authentication and routing chores. If you don't mind it being mostly 100Mbps ports, with only 2 GigEth GBIC ports (one transmit, one recieve only), you can get a used C3550 for like $80.