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.
in win:
one BULK transfer include many pairs transaction(PING and OUT),and
transaction OUT can sent 512bytes, one BULK transfer sent 265250bytes.
the modem used option.c driver which defined out urb maxsize is 4096,I
don't know why the data transferred in usb bus is so small.
Did the packet size lead to the difference about uploadspeed?
keenel version: 2.6.31
usb2.0 EHCI
mtu 1050
thanks a lot.
Ming!
--------------------------------------------------------
ZTE Information Security Notice: The information contained in this mail is solely property of the sender's organization. This mail communication is confidential. Recipients named above are obligated to maintain secrecy and are not permitted to disclose the contents of this communication to others.
This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the originator of the message. Any views expressed in this message are those of the individual sender.
This message has been scanned for viruses and Spam by ZTE Anti-Spam system.
--
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
