Asyn0 Terminal server dropping data

Digi TransPort WR (Series)
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1

Hi All:

My System:
Model: TransPort WR21
Part Number: WR21-U82B-DE1-XX
Ethernet 0 MAC Address: 00:04:2D:04:2C:84
Serial: 273540

Firmware Version: 5.2.15.6 (Aug 17 2016 17:42:05)
SBIOS Version: 7.56u
Build Version: WW
HW Version: 1201a

CPU Utilization: 1% (Min: 1%, Max: 55%, Avg: 1%)
Up Time: 38 minutes 26 seconds
Date and Time: 20 Jan 2017 19:09:03
Total Memory: 131072 KB
Used Memory: 43023 KB
Free Memory: 88049 KB

Mobile Module: GOBI UMTS
SW Opts: 0x141 0x0
SW Cnts: 5 64 0 0 3 0 0 0 0 17 0 0 0 0 0 0 0 0 0 0
Switch Mode: Hub

Set up:
I have the Async0 terminal service running and Async0 is assigned to TCP 4000. I have connected to this port using ncat as follows:


jserink@jserinki7 ~ $ ncat 192.168.102.21 4000
0	zero
1	one
2	two
3	three
4	four
5	five
6	six
7	seven
8	eight
9	nine
10	ten
11	eleven
12	twelve
13	thirteen
14	fourteen
15	fifteen
16	sixteen
17	seventeen
18	eighteen
19	nineteen
20	twenty
21	twenty-one
22	twenty-two
23	twenty-three
24	twenty-four
25	twenty-five
26	twenty-six
27	twenty-seven
28	twenty-eight
29	twenty-nine
30	thirty
31	thirty-one
32	thirty-two

This is what the trace shows on the router:



   -----   20-1-2017  19:05:51.860   ------
   ASY 0 DCE to DTE: 
   
   30 09 7A 65 72 6F 0A                                0.zero.
   ----------
   -----   20-1-2017  19:05:52.590   ------
   ASY 0 DCE to DTE: 
   
   31 09 6F 6E 65 0A 32 09 74 77 6F 0A 33 09 74 68     1.one.2.two.3.th
   72 65 65 0A 34 09 66 6F 75 72 0A 35 09 66 69 76     ree.4.four.5.fiv
   65 0A 36 09 73 69 78 0A 37 09 73 65 76 65 6E 0A     e.6.six.7.seven.
   38 09 65 69 67 68 74 0A 39 09 6E 69 6E 65 0A 31     8.eight.9.nine.1
   30 09 74 65 6E 0A 31 31 09 65 6C 65 76 65 6E 0A     0.ten.11.eleven.
   31 32 09 74 77 65 6C 76 65 0A 31 33 09 74 68 69     12.twelve.13.thi
   72 74 65 65 6E 0A 31 34 09 66 6F 75 72 74 65 65     rteen.14.fourtee
   6E 0A 31 35 09 66 69 66 74 65 65 6E 0A 31 36 09     n.15.fifteen.16.
   ----------
   -----   20-1-2017  19:05:53.300   ------
   ASY 0 DCE to DTE: 
   
   33 32 09 74 68 69 72 74 79 2D 74 77 6F 0A           32.thirty-two.

As you can see there are anomalies. Adter the first 8 bytes, the messages gets split and sent. The next 128 bytes then get sent, after which 128 bytes are lost and the last 14 bytes are there.

What are happening to that 128 bytes that are getting lost?

Cheers,
john

2

More information. This is if I connect using putty as a raw socket client:


68 65 6C 6C 6F 20 66 72 6F 6D 20 70 75 74 74 79     hello.from.putty
   ----------
   -----   20-1-2017  19:14:44.020   ------
   ASY 0 DCE to DTE: 
   
   0D 0A                                               ..
   ----------
   -----   20-1-2017  19:15:08.230   ------
   ASY 0 DCE to DTE: 
   
   30 09 7A 65 72 6F                                   0.zero
   ----------
   -----   20-1-2017  19:15:08.230   ------
   ASY 0 DCE to DTE: 
   
   0D 0A                                               ..
   ----------
   -----   20-1-2017  19:15:08.230   ------
   ASY 0 DCE to DTE: 
   
   31 09 6F 6E 65                                      1.one
   ----------
   -----   20-1-2017  19:15:08.230   ------
   ASY 0 DCE to DTE: 
   
   0D 0A 32 09 74 77 6F                                ..2.two
   ----------
   -----   20-1-2017  19:15:08.230   ------
   ASY 0 DCE to DTE: 
   
   0D 0A 33 09 74 68 72 65 65 0D 0A 34 09 66 6F 75     ..3.three..4.fou
   72 0D 0A 35 09 66 69 76 65 0D 0A 36 09 73 69 78     r..5.five..6.six
   0D 0A 37 09 73 65 76 65 6E 0D 0A                    ..7.seven..
   ----------
   -----   20-1-2017  19:15:08.550   ------
   ASY 0 DCE to DTE: 
   
   38 09 65 69 67 68 74 0D 0A 39 09 6E 69 6E 65 0D     8.eight..9.nine.
   0A 31 30 09 74 65 6E 0D 0A 31 31 09 65 6C 65 76     .10.ten..11.elev
   65 6E 0D 0A 31 32 09 74 77 65 6C 76 65 0D 0A 31     en..12.twelve..1
   33 09 74 68 69 72 74 65 65 6E 0D 0A 31 34 09 66     3.thirteen..14.f
   6F 75 72 74 65 65 6E 0D 0A 31 35 09 66 69 66 74     ourteen..15.fift
   65 65 6E 0D 0A 31 36 09 73 69 78 74 65 65 6E 0D     een..16.sixteen.
   0A 31 37 09 73 65 76 65 6E 74 65 65 6E 0D 0A 31     .17.seventeen..1
   38 09 65 69 67 68 74 65 65 6E 0D 0A 31 39 09 6E     8.eighteen..19.n
   ----------
   -----   20-1-2017  19:15:09.750   ------
   ASY 0 DCE to DTE: 
   
   33 32 09 74 68 69 72 74 79 2D 74 77 6F              32.thirty-two
   ----------
   -----   20-1-2017  19:15:09.750   ------
   ASY 0 DCE to DTE: 
   
   0D 0A                                               ..
   ----------

You can see that putty preserves the CR-LF whereas the bash console has on CR.

Same behavior, 128 bytes missing.

Cheers,
John

3

Add an IP level trace to confirm you are receiving the packet.