Inert Detritus The Internet's dust bunnies

14 February 2010 @ 12am

Briefly: Network Topologies

Things I learned today: net­work link-lay­er topol­o­gy makes a huge dif­fer­ence for wireless.

My file trans­fers via 802.11n from one lap­top to anoth­er were pret­ty slow: max sus­tained through­put was 3–4 MB/sec. As an exper­i­ment in solv­ing unre­lat­ed Air­Port base sta­tion asso­ci­a­tion issues, I plugged one lap­top (that’s already wired up to the TV as a media cen­ter of sorts) into the base sta­tion via GigE. Because the AP no longer has to nego­ti­ate with two clients on the same slice of spec­trum for net­work traf­fic, my inter-machine trans­fer rate jumped to 15–18 MB/sec.

Note that this only applies when the lap­top is asso­ci­at­ed to the base sta­tion that the oth­er client is wired to. Since I have both a Time Cap­sule and an Air­Port Extreme, when the wire­less lap­top roams to the Time Cap­sule, its link to the Time Cap­sule is con­tend­ing with the Time Cap­sule <—> Air­Port Extreme wire­less link, and the speed falls off again.

The net­work lay­out looks some­thing like this: