Hi,
A PC software is communicated with a GPRS modem over the
serial port.
These are the data sent from the PC to the modem.
They seems to be PPP (LCP) packets.
7E FF 7D 23 C0 21 7D 21 7D 20 7D 20 32 7D 22 7D 26 7D 20 7D 20 7D 20
7D 20 7D 25 7D 26 5D CC 7D 24 BF 7D 27 7D 22 7D 28 7D 22 7D 2D 7D 23
7D 26 7D 31 7D 24 7D 26 4E 7D 33 7D 37 7D 21 7D 22 B7 3A 56 6E 7C 40
8E 7D B1 31 37 61 7D 26 3E 49 A8 7D 20 7D 20 7D 20 7D 20 F8 B7 7E
7E FF 7D 23 C0 21 7D 21 7D 21 7D 20 7D 2A 7D 22 7D 26 7D 20 7D 20 7D
20 7D 20 58 7B 7E
I tried to form a snoop file (see the attachment),
and observed the protocol. I tried many things (tried
decode as PPP, changed the 16th octet in the
snoop file for Ethernet, FDDI, Other ... datalink types)
but never decode the packets correctly.
What is wrong?
Is it due to PPP connection between the modems, and
no Ethernet datalink is present?
Best regards,
Bora Dikmen
Snoop file dump: -----------------------------
File header: ---------------------------------
snoop version Ethernet
736E6F6F70000000 00000002 00000004
1. packet header: ----------------------------
0000005B 0000005B 00000074 00000000 00000001 00000001
1. packet data: ------------------------------
7E FF 7D 23 C0 21 7D 21 7D 20 7D 20 32 7D 22 7D 26 7D 20 7D 20 7D 20
7D 20 7D 25 7D 26 5D CC 7D 24 BF 7D 27 7D 22 7D 28 7D 22 7D 2D 7D 23
7D 26 7D 31 7D 24 7D 26 4E 7D 33 7D 37 7D 21 7D 22 B7 3A 56 6E 7C 40
8E 7D B1 31 37 61 7D 26 3E 49 A8 7D 20 7D 20 7D 20 7D 20 F8 B7 7E 00
(one padded 00)
2. packet header: ----------------------------
0000001D 0000001D 00000038 00000000 00000002 00000002
2. packet data: ------------------------------
7E FF 7D 23 C0 21 7D 21 7D 21 7D 20 7D 2A 7D 22 7D 26 7D 20 7D 20 7D
20 7D 20 58 7B 7E 00 00 00 (three padded 00)
Attachment:
bora.snoop
Description: Binary data