Tera TermThe packet behind the faulty packet will transfered anlways, because the receiver expect the "really" faulty packet.
This Log is generated on the receiver side.
-->(incomming file)
<--(handshake)
<--15 15 15 15 15 15
-->01 01 FE 65 63 68 6F 20 6F 66 66 0D 0A 3A 4C 4F 4F 50 0D 0A 63 64 20 5C 0D 0A 63 6C 73
0D 0A 65 63 68 6F 2E 0D 0A 65 63 68 6F 20 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A
2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A
2A 0D 0A 65 63 68 6F 20 2A 2A 2A 2A 20 20 20 20 20 42 20 3D 20 50 72 6F 67 72 61 6D 6D 69
65 72 65 6E 20 42 49 4F 53 20 20 20 8A
<--06
-->01 01 FE 65 63 68 6F 20 6F 66 66 0D 0A 3A 4C 4F 4F 50 0D 0A 63 64 20 5C 0D 0A 63 6C 73
0D 0A 65 63 68 6F 2E 0D 0A 65 63 68 6F 20 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A
2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A 2A
2A 0D 0A 65 63 68 6F 20 2A 2A 2A 2A 20 20 20 20 20 42 20 3D 20 50 72 6F 67 72 61 6D 6D 69
65 72 65 6E 20 42 49 4F 53 20 20 20 8A
<--06
!!!!! Some Packet not shown !!!!!
-->01 05 FA 52 4F 52 4C 45 56 45 4C 20 35 20 67 6F 74 6F 20 45 4E 44 0D 0A 69 66 20 45 52
52 4F 52 4C 45 56 45 4C 20 34 20 67 6F 74 6F 20 45 44 0D 0A 69 66 20 45 52 52 4F 52 4C 45
56 45 4C 20 33 20 67 6F 74 6F 20 45 44 0D 0A 69 66 20 45 52 52 4F 52 4C 45 56 45 4C 20 32
20 67 6F 74 6F 20 50 52 4F 0D 0A 69 66 20 45 52 52 4F 52 4C 45 56 45 4C 20 31 20 67 6F 74
6F 20 50 52 4F 0D 0A 69 66 20 45 52 6F
<--06
-->01 06 F9 52 4F 52 4C 45 56 45 4C 20 30 20 67 6F 74 6F 20 4C 30 0D 0A 0D 0A 0D 0A 67 6F
74 6F 20 45 4E 44 0D 0A 0D 0A 3A 45 44 0D 0A 0D 0A 65 64 69 74 20 5C 65 74 68 5F 6D 61 63
5C 65 65 6C 6F 67 2E 64 61 74 0D 0A 0D 0A 67 6F 74 6F 20 4C 4F 4F 50 0D 0A 0D 0A 0D 0A 0D
0A 3A 4C 30 0D 0A 65 63 68 6F 2E 0D 0A 65 63 68 6F 2E 0D 0A 65 63 68 6F 20 21 21 21 21 20
55 6E 72 77 61 72 74 65 74 65 73 20 5F
<--15 <=== This NAK was respond for test only. The packet was correct. The checksum was set to wrong value for this test only once.
The respond for the packet 6 was NAK, but Teraterm send the packet 7 instead the 6 again.
Checksum calc 96, rec 95
-->01 07 F8 45 4E 44 45 20 21 21 21 21 0D 0A 65 63 68 6F 20 45 52 52 4F 52 4C 45 56 45 4C
20 3D 20 30 0D 0A 65 63 68 6F 2E 0D 0A 67 6F 74 6F 20 45 4E 44 0D 0A 3A 4C 45 32 35 35 0D
0A 65 63 68 6F 2E 0D 0A 65 63 68 6F 20 21 21 21 21 20 55 6E 72 77 61 72 74 65 74 65 73 20
45 4E 44 45 20 21 21 21 21 0D 0A 65 63 68 6F 20 45 52 52 4F 52 4C 45 56 45 4C 20 3D 20 32
35 35 0D 0A 67 6F 74 6F 20 45 4E 44 08
<--15
expexted Nr 6, received 7 <=== The receiver knows packet 6 was wrong, but TereTerm sends the 7, because
The NAK responce for packet 6 was recognised too late on packet 7.
-->01 07 F8 45 4E 44 45 20 21 21 21 21 0D 0A 65 63 68 6F 20 45 52 52 4F 52 4C 45 56 45 4C
20 3D 20 30 0D 0A 65 63 68 6F 2E 0D 0A 67 6F 74 6F 20 45 4E 44 0D 0A 3A 4C 45 32 35 35 0D
0A 65 63 68 6F 2E 0D 0A 65 63 68 6F 20 21 21 21 21 20 55 6E 72 77 61 72 74 65 74 65 73 20
45 4E 44 45 20 21 21 21 21 0D 0A 65 63 68 6F 20 45 52 52 4F 52 4C 45 56 45 4C 20 3D 20 32
35 35 0D 0A 67 6F 74 6F 20 45 4E 44 08
<--15
expexted Nr 6, received 7
AND SO ON
This is the same as Ticket #22342. The problem seems still not fixed. See also http://logmett.com/forum/viewtopic.php?f=2&t=354
Is this problem occurs with latest version of Tera Term?
On Xmodem transfer send file. The receiver is stated first and is sending NAKs. Tera Term receive a NAK and start with the first packet transfer. BUT this NAK maybe was not the last one before start sending. On the beginning (before sending the first packet) the RX buffer was not flushed and a additionel NAK will be received and Tera Term sends the first packet AGAIN. That is not the main problem. The problem is now, that the answers in the RX buffer are always one packet behind. If one packet is transfered wrong, the respond for this packet is ACK, and the NAK is comming after the next packet. So the wrong packet is not detect, and a good packet is sended twice.
You can se it on each xmodem file send. The first packet is always sendet twice if the "file-receicer" has send more then one "Initianl"- NAK