I would approaching to be capable of see the bandwidth that respectively of the computers connected to my LAN is using (mainly wireless connections). My router (a Linksys WRT54GL) does not seem to be to volunteer this monitoring function.
Answers:
I recommend MRTG which is a free utility which have be scipted for believably trouble-free access.
It runs on a PC (must own Perl loaded) and will monitor adjectives devices via SNMP including the PC itself CPU mem etc
It outputs in a nice graphical format (supplies on Web server) and will out 5min 1 time and 1 week outputs.
It can be modified to monitor anything some surfers use it to monitor the tides for best surf
Did I mention it is Free