On Sat, Jul 24, 2004 at 02:48:18PM +0930, Suniljit Singh wrote:
> Just a quick question. Does Ethereal detect low-level bytes or is it purely a
> high-level packet-sniffing analyser?
How low-level are you thinking?
Ethereal relies on libpcap to deliver packets, and that doesn't go, for
example, all the way down to the 8B/10B encoding on gigabit Ethernet, so
you get decoded 8-bit bytes, not 10-bit symbols.
It does, however, go down to the link-layer header on most network
types, e.g. you get the Ethernet header as well as the higher-level
headers in the Ethernet payload.
> Does Ethereal have the ability to detect Bit Error Rate of a transfer of
> Packet Error Rate?
It would have to either
1) get those numbers from the underlying OS
or
2) compute them from the data.
libpcap doesn't have a way of getting a bit error rate from the OS, so
Ethereal doesn't get that. If the BER can be computed if you get bad
packets as well as good packets (e.g., by checking the CRC), and bad
packets are supplied by the OS via the packet capture mechanism to
libpcap, code could conceivably be added to Ethereal to compute that.
The case for packet error rates is similar.