Network Associates (or whoever they are these days) Sniffer will do most, if not all of the things you're lookg for.
I'm not sure about "generate" late collisions, but it'll certainly capture, detect, and diaply them.
If this is for a Lab environment and you need to generate good & (varieties of) bad traffic, then you may also want to check out a SmartBits.
SmartBits has interfaces for ATM, Ethernet (up to 10GigE), optical & copper, Token Ring, DS3 ... nearly anything.
Someone also used to have software called "The Cloud" that could take a snapshot of a transmission environment (Ethernet, Serial, whatever) and replicate it for the Lab (and allow you to manually vary the transmission parameters, i.e., crank up the latency, add congestion, blow QOS, etc)
Another software package that is extremely useful is IXIA Chariot. Chariot is an Application Layer stream generator, single or multiple endpoints to other single or multiple endpoints (single or multiple streams to each of the single or multiple endpoints).
Each stream can emulate virtually any kind of traffic, and you can mix-and-match a variety of streams (a couple HTTP, a couple FTP, a couple SAP, a couple VoIP ... pretty much anything in any combination).
Actually, "Stream Generator" is a very bad description, it produces the most amazing reports, fully documenting each test phase. It's an awesome test and analysis tool ... because it tests the entire system: computer platform, operating system, NIC(s), infrastructure ... the whole ball of wax as it would work in a production environment ... throughput, latencies, drops ... everything.... and you can adjust the transmission parameters to emulate nearly any stuation.
These are the same folks that brought you "Qcheck" a free endpoint-to-endpoint test for throughput, latency, and drop.
None of the above (except Qcheck) are cheap, but they are all recognized by "the industry" as reliable, accurate, reproduceble testing & analysis platforms.
Good Luck
Scott
