Am Donnerstag, 19. November 2009 14:22:44 schrieb zhao.ming9@xxxxxxxxxx: > Hi Alan, > > I have used usb-modem to test upload speed in Linux.but something puzzled > me. > > at the same place and with same device,upload speed differ from linux and > windows. > > in linux: > upload speed is only 2Mbits/s. > in windows: > upload speed is about 4.1Mbits/s. > > > I dissectted the usb analyzer log and found some difference between linux > and windows. > > in linux: > one BULK transfer include one pair transaction(PING and OUT),and > transaction OUT only sent 256bytes,so one BULK transfer sent 256bytes. What you see there is equal to the PPP buffer size. David Miller has just accepted a patch that bumps this to 4096 bytes. Could you check whether this helps? Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
