How do we defind VOIP packet?

When sniffing a data stream from a LAN, is there a fast way to identify a VoIP packet?

If you want to record the VoIP packets, there are solutions for it on the market, the most economical and easy to inplement will be to have "VoIP Recording Solution" the data collector sitting next to the gateway. The software sniffs the packets duplicate them and store them on a sequal server either for replay later or for instant monitoring we have sucesfully tested the solution with VocalTec Gateways as well as major IPPBX
The monitoring can be done from a remote site but the collector has to sit next to the gateway. Unless you are using a softswitch than you can do everything remotely

Nuriel

A lot of packet-kinds can be described as VoIP: RTCP, RTP and etc.
Also depends on the protocol used. The best tool available is to use Ethereal.
It does recognize "VoIP" packets.

Btw, the question "how to detect VoIP packets" sounds like "How to detect a
vehicle that has passed on some road".
Vehicles can be cars, trucks, TANKS, bikes and etc.