[Guy Harris <gharris@xxxxxxxxx>]

david martinez wrote:
> Hi, i'm developing a dissector but i don`t know what
> is command tvb-set_reported_length for;

It's for protocols that have their own length field, which specifies the 
packet's real length.  IPv4, for example, has this - a short IPv4 packet 
transmitted over Ethernet would be padded to the minimum Ethernet packet 
length, but, from the point of view of IP and protocols running on top 
of IP, the length is as specified in the IP total length field, not the 
length as transmitted on the Ethernet.

> it's necessary
> that it exists always, becouse,in my dissector,when i
> deleted that line the dissector works but if i put
> that line it doesn't work.

Does your protocol have a length field like that?  What "doesn't work" 
in your dissector if you don't use tvb_set_reported_length()?  Most 
protocols *don't* need it.