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I need HELP !!!
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Hi there,
 I use Linux (kernel 2.0.36 and ax25-utils-2.1.42a) for packet radio
with a
Soundcard modem set for 9600bps. For testing purpose the 2 PC's are link
by
coaxial cable. The ax25 and soundmodem are compiled as modules.

The PC's are called yo3kxi.ampr.org and yo3gih.ampr.org.
After boot I use the following script to load modules and initialize the
network (only the names and callsigns are diferent between the 2 PC's):

#!/bin/sh
insmod ax25
insmod hdlcdrv
insmod soundmodem
sethdlc -p -i sm0 mode sbc:fsk9600 io 0x220 irq 5 dma 1 dma2 3 serio
0x2f8
sethdlc -i sm0 -a txd 10 slot 20 ppersist 64 half
ifconfig sm0 hw ax25 YO3KXI mtu 256  up
ifconfig sm0 44.182.5.1 netmask 255.255.255.0 broadcast 44.182.255.255
route add -net 44.182.0.0 netmask 255.255.0.0 window 1024 irtt 600 dev
sm0
smmixer s=line o=0

The parameters in /proc/sys/net/ax25/sm0 are the same on the two
machines:
/proc/sys/net/ax25/sm0/
ax25_default_mode       = 0
backoff_type            = 1
connect_mode            = 1 (set by me because the default is 2 !!)
extended_window_size    = 32
idle_timeout            = 0
ip_default_mode         = 0
maximum_packet_length   = 256
maximum_retry_count     = 10
standard_window_size    = 7 (set by me !)
t1_timeout              = 100
t2_timeout              = 30
t3_timeout              = 3000

So, with all that done the link works, one PC send more that one packet
at a
time, but the other, after receiving 2 packets send an ACK frame and
generate
an interference and the rest of the packets are lost.

For example I make a ftp from yo3gih.ampr.org to yo3kxi.ampr.org and
when data
are send I watch the connection with " listen -a " and I see something
like
this:

listen -a  at  yo3kxi.ampr.org :
--------------------------------

Port radio: AX25: YO3GIH->YO3KXI <UI> pid=IP
IP: len 40 44.182.6.17->44.182.5.1 ihl 20 ttl 64 tos 8 prot TCP
TCP: 1026->ftp-data Seq x7a7e9f29 Ack x91c2ce37 ACK Wnd 1024

Port radio: AX25: YO3KXI->YO3GIH <UI> pid=IP
IP: len 256 44.182.5.1->44.182.6.17 ihl 20 ttl 64 tos 8 prot TCP
TCP: ftp-data->1026 Seq x91c2ce37 Ack x7a7e9f29 ACK Wnd 1024 Data 216
0000  ..����..1/2����.~...x����.����.....u....���.v.�.����......����....
0040 
......2.1/2�����..�.�P�.$.�.�..�..�..1/2����.�.~�..����..1/2����.~��.�
0080 
���....�.����....�.����....�.����.....1/2����.1/2������J...�x..����.
00C0  1/2.���.1/2t���...���..h���.

Port radio: AX25: YO3KXI->YO3GIH <UI> pid=IP
IP: len 256 44.182.5.1->44.182.6.17 ihl 20 ttl 64 tos 8 prot TCP
TCP: ftp-data->1026 Seq x91c2cf0f Ack x7a7e9f29 ACK Wnd 1024 Data 216
0000 
1/2.���.1/2d���...���..L���.1/2����.1/2����.E..�...T�������..1/2����.E..�|
0040 
����.�..T���.1/2.����.�����...t����.�����..�...t���...���..p���.1/2`
0080  ����.����.....E..�.�.����..X���..1/2����.E.�.�����.�..X����.�����.
00C0  �����...p����.�����.����

Port radio: AX25: YO3KXI->YO3GIH <UI> pid=IP
IP: len 256 44.182.5.1->44.182.6.17 ihl 20 ttl 64 tos 8 prot TCP
TCP: ftp-data->1026 Seq x91c2cfe7 Ack x7a7e9f29 ACK Wnd 1024 Data 216
0000 
�...x���..h���.1/2.����..�...h���..p���..1/2l����.����.....E..�(�.��
0040 
��..\���.1/2����.E.�.�����.�.1/2\����.�����...l����.�����...d����.1�
0080  .1/2`���.�.�..�..1/2`���..d���..l���.�.D�����f��.�Eu.��C�..����.
���
00C0  f��.�E..�......����.����

Port radio: AX25: YO3KXI->YO3GIH <UI> pid=IP
IP: len 256 44.182.5.1->44.182.6.17 ihl 20 ttl 64 tos 8 prot TCP
TCP: ftp-data->1026 Seq x91c2ce37 Ack x7a7e9f29 ACK Wnd 1024 Data 216
0000  ..����..1/2����.~...x����.����.....u....���.v.�.����......����....
0040 
......2.1/2�����..�.�P�.$.�.�..�..�..1/2����.�.~�..����..1/2����.~��.�
0080 
���....�.����....�.����....�.����.....1/2����.1/2������J...�x..����.
00C0  1/2.���.1/2t���...���..h���.

Port radio: AX25: YO3GIH->YO3KXI <UI> pid=IP
IP: len 40 44.182.6.17->44.182.5.1 ihl 20 ttl 64 tos 8 prot TCP
TCP: 1026->ftp-data Seq x7a7e9f29 Ack x91c2cfe7 ACK Wnd 1024

Port radio: AX25: YO3KXI->YO3GIH <UI> pid=IP
IP: len 256 44.182.5.1->44.182.6.17 ihl 20 ttl 64 tos 8 prot TCP
TCP: ftp-data->1026 Seq x91c2cfe7 Ack x7a7e9f29 ACK Wnd 1024 Data 216
0000 
�...x���..h���.1/2.����..�...h���..p���..1/2l����.����.....E..�(�.��
0040 
��..\���.1/2����.E.�.�����.�.1/2\����.�����...l����.�����...d����.1�
0080  .1/2`���.�.�..�..1/2`���..d���..l���.�.D�����f��.�Eu.��C�..����.
���
00C0  f��.�E..�......����.����

Port radio: AX25: YO3GIH->YO3KXI <UI> pid=IP
IP: len 40 44.182.6.17->44.182.5.1 ihl 20 ttl 64 tos 8 prot TCP
TCP: 1026->ftp-data Seq x7a7e9f29 Ack x91c2d0bf ACK Wnd 1024

listen -a  at yo3gih.ampr.org :
-------------------------------

Port radio: AX25: YO3GIH->YO3KXI <UI> pid=IP
IP: len 40 44.182.6.17->44.182.5.1 ihl 20 ttl 64 tos 8 prot TCP
TCP: 1026->ftp-data Seq x7a7e9f29 Ack x91c2ce37 ACK Wnd 1024

Port radio: AX25: YO3KXI->YO3GIH <UI> pid=IP
IP: len 256 44.182.5.1->44.182.6.17 ihl 20 ttl 64 tos 8 prot TCP
TCP: ftp-data->1026 Seq x91c2ce37 Ack x7a7e9f29 ACK Wnd 1024 Data 216
0000  ..����..1/2����.~...x����.����.....u....���.v.�.����......����....
0040 
......2.1/2�����..�.�P�.$.�.�..�..�..1/2����.�.~�..����..1/2����.~��.�
0080 
���....�.����....�.����....�.����.....1/2����.1/2������J...�x..����.
00C0  1/2.���.1/2t���...���..h���.

Port radio: AX25: YO3KXI->YO3GIH <UI> pid=IP
IP: len 256 44.182.5.1->44.182.6.17 ihl 20 ttl 64 tos 8 prot TCP
TCP: ftp-data->1026 Seq x91c2cf0f Ack x7a7e9f29 ACK Wnd 1024 Data 216
0000 
1/2.���.1/2d���...���..L���.1/2����.1/2����.E..�...T�������..1/2����.E..�|
0040 
����.�..T���.1/2.����.�����...t����.�����..�...t���...���..p���.1/2`
0080  ����.����.....E..�.�.����..X���..1/2����.E.�.�����.�..X����.�����.
00C0  �����...p����.�����.����

Port radio: AX25: YO3GIH->YO3KXI <UI> pid=IP
IP: len 40 44.182.6.17->44.182.5.1 ihl 20 ttl 64 tos 8 prot TCP
TCP: 1026->ftp-data Seq x7a7e9f29 Ack x91c2cfe7 ACK Wnd 1024

Port radio: AX25: YO3KXI->YO3GIH <UI> pid=IP
IP: len 256 44.182.5.1->44.182.6.17 ihl 20 ttl 64 tos 8 prot TCP
TCP: ftp-data->1026 Seq x91c2ce37 Ack x7a7e9f29 ACK Wnd 1024 Data 216
0000  ..����..1/2����.~...x����.����.....u....���.v.�.����......����....
0040 
......2.1/2�����..�.�P�.$.�.�..�..�..1/2����.�.~�..����..1/2����.~��.�
0080 
���....�.����....�.����....�.����.....1/2����.1/2������J...�x..����.
00C0  1/2.���.1/2t���...���..h���.

Port radio: AX25: YO3GIH->YO3KXI <UI> pid=IP
IP: len 40 44.182.6.17->44.182.5.1 ihl 20 ttl 64 tos 8 prot TCP
TCP: 1026->ftp-data Seq x7a7e9f29 Ack x91c2cfe7 ACK Wnd 1024

Port radio: AX25: YO3KXI->YO3GIH <UI> pid=IP
IP: len 256 44.182.5.1->44.182.6.17 ihl 20 ttl 64 tos 8 prot TCP
TCP: ftp-data->1026 Seq x91c2cfe7 Ack x7a7e9f29 ACK Wnd 1024 Data 216
0000 
�...x���..h���.1/2.����..�...h���..p���..1/2l����.����.....E..�(�.��
0040 
��..\���.1/2����.E.�.�����.�.1/2\����.�����...l����.�����...d����.1�
0080  .1/2`���.�.�..�..1/2`���..d���..l���.�.D�����f��.�Eu.��C�..����.
���
00C0  f��.�E..�......����.����

Port radio: AX25: YO3GIH->YO3KXI <UI> pid=IP
IP: len 40 44.182.6.17->44.182.5.1 ihl 20 ttl 64 tos 8 prot TCP
TCP: 1026->ftp-data Seq x7a7e9f29 Ack x91c2d0bf ACK Wnd 1024

As you cant see yo3kxi.ampr.org send 4 data packets, but yo3gih.ampr.org
after receiving the second packet send an ACK frame and generate an
interference and the rest of the packets are lost. Hopefully the
protocol is
smart enough to notest that the yo3gih.ampr.org is not able to receive
more
that 2 packets, and reduce the number of transmitted packets at one
time, so
the ftp transfer still work but slow!
>From time to time yo3kxi.ampr.org tries the connection by sendin 4
packets,
but this makes the transfer rate even smaller.

What is the problem ?

For tree weeks I tried different parameters for t2, t1, t3,
ax25_default_mode
etc., but I have failed.

-- 
###################################################################
#    Minta Adrian - YO3GIH                    phone: 04+092451899 #
#   mailto:[EMAIL PROTECTED] http://www.csit-sun.pub.ro/~gygy/ #     
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