Which port is used by udp communication，Is it coded in source code？

where can I find it？

Thanks
niu

AFAIK it's (a) included as part of the listening port. (b) yes there may be a port that is hard coded into LW for some messages. I vaguely remember reading with the older earlier LW 4 versions it was similar to the official Gnutella network port of 6346. From memory it was around that range of 6343 to 6346 or something. I may be wrong & will be happy to be corrected.

LW does use UDP for some messaging.