tftp blocksize increase on RHEL 5.8

[张廉]

Hi There
I am doing setup tftp to download image via WAN/MAN link now. but the
speed of download is quite slow.
3.9MB file download vis tftp needs more than 27 seconds now.

I see there is way to increase the blocksize of data transfer from 512
bytes to 65535.
reference link:
http://blackfin.uclinux.org/doku.php?id=setting_up_a_tftp_server.
So I did a modification on /etc/xinetd.d/tftp, and made a test.  The
result is not good, just same as before.
Could anyone help to find whether the command is correct or wrong ?
and guide me how to increase data size to improve transfer speed.

The link between 2 sites is around 200M MAN link.
Below are modified tftp configuration file and command what I used:

m at server:/tmp$ tftp -v -l 10.150.25.102 -c  get Image.bin
Connected to 10.150.25.102 (10.150.25.102), port 69
getting from 10.150.25.102:Image.bin to Image.bin [netascii]
Received 4094588 bytes in 29.5 seconds [1111030 bit/s]


service tftp
{
        socket_type        = dgram
        protocol              = udp
        wait                    = yes
        user                    = root
        se rver                 = /usr/sbin/in.tftpd
        server_args          = -v --blocksize 16268 -s /tftpboot
        disable                = no
        per_source          = 11
        cps                     = 100 2
        flags                   = IPv4
}

Thanks
lian