x25 windowsize-problem ?!?

[rabeder]

hi,

sometimes i have problems wit a x25 connection.

a x25 workstation has sometimes problem when it tries to connect.

i did a "debug x25" and saw following problem:

Feb 25 08:51:09.882: Serial0/1: X.25 I D1 RR (3) 8 lci 1 PR 1

Feb 25 08:51:09.886: [10.22.208.2,11597/192.168.128.2,1998]: XOT I D1 RR (3) 8 l

ci 1 PR 2

Feb 25 08:51:09.886: Serial0/0: X.25 O D1 RR (3) 8 lci 1 PR 2

Feb 25 08:51:09.886: Serial0/1: X.25 I D1 RR (3) 8 lci 1 PR 2

Feb 25 08:51:09.890: Serial0/1: X.25 O D1 Data (15) 8 lci 1 PS 2 PR 5

Feb 25 08:51:09.890: Serial0/1: X.25 O D1 Data (15) 8 lci 1 PS 3 PR 5

Feb 25 08:51:09.890: Serial0/0: X.25 I D1 Data (15) 8 lci 1 PS 2 PR 5

Feb 25 08:51:09.894: [10.22.208.2,11597/192.168.128.2,1998]: XOT O D1 Data (15)

8 lci 1 PS 2 PR 5

Feb 25 08:51:09.894: Serial0/0: X.25 I D1 Data (15) 8 lci 1 PS 3 PR 5

Feb 25 08:51:09.894: [10.22.208.2,11597/192.168.128.2,1998]: XOT O D1 Data (15)

8 lci 1 PS 3 PR 5

Feb 25 08:51:09.910: [10.22.208.2,11597/192.168.128.2,1998]: XOT I D1 Data (28)

8 lci 1 PS 5 PR 2

Feb 25 08:51:09.910: Serial0/0: X.25 O D1 Data (28) 8 lci 1 PS 5 PR 2

Feb 25 08:51:09.910: Serial0/1: X.25 I D1 Data (28) 8 lci 1 PS 5 PR 2

Feb 25 08:51:09.954: [10.22.208.2,11597/192.168.128.2,1998]: XOT I D1 Data (28)

8 lci 1 PS 6 PR 2

Feb 25 08:51:09.954: Serial0/0: X.25 O D1 Data (28) 8 lci 1 PS 6 PR 2

Feb 25 08:51:09.958: Serial0/1: X.25 I D1 Data (28) 8 lci 1 PS 6 PR 2

Feb 25 08:51:09.958: [10.22.208.2,11597/192.168.128.2,1998]: XOT I D1 RR (3) 8 l

ci 1 PR 3

Feb 25 08:51:09.958: Serial0/0: X.25 O D1 RR (3) 8 lci 1 PR 3

Feb 25 08:51:09.962: Serial0/1: X.25 I D1 RR (3) 8 lci 1 PR 3

Feb 25 08:51:09.962: [10.22.208.2,11597/192.168.128.2,1998]: XOT I D1 RR (3) 8 l

ci 1 PR 4

Feb 25 08:51:09.962: Serial0/0: X.25 O D1 RR (3) 8 lci 1 PR 4

Feb 25 08:51:09.966: Serial0/1: X.25 I D1 RR (3) 8 lci 1 PR 4

Feb 25 08:51:09.966: [10.22.208.2,11597/192.168.128.2,1998]: XOT I D1 Data (28)

8 lci 1 PS 7 PR 4

Feb 25 08:51:09.966: Serial0/0: X.25 O D1 Data (28) 8 lci 1 PS 7 PR 4

Feb 25 08:51:09.970: Serial0/1: X.25 I D1 Data (28) 8 lci 1 PS 7 PR 4

Feb 25 08:51:09.970: X.25 Data packet, Bad P(S), Receive window violation

Feb 25 08:51:09.970: Serial0/1: X.25 O D1 Reset (5) 8 lci 1

Feb 25 08:51:09.970: Cause 0, Diag 1 (DTE originated/Invalid P(S))

Feb 25 08:51:09.974: Serial0/0: X.25 I D1 Reset (5) 8 lci 1

Feb 25 08:51:09.974: Cause 0, Diag 1 (DTE originated/Invalid P(S))

Feb 25 08:51:09.974: Serial0/0: X.25 O D2 Reset Confirm (3) 8 lci 1

Feb 25 08:51:09.974: [10.22.208.2,11597/192.168.128.2,1998]: XOT O D1 Reset (5)

8 lci 1

Feb 25 08:51:09.974: Cause 0, Diag 1 (DTE originated/Invalid P(S))

Feb 25 08:51:09.974: Serial0/1: X.25 I D2 Reset Confirm (3) 8 lci 1

Feb 25 08:51:09.978: Serial0/1: X.25 O R1 Clear (5) 8 lci 1

Feb 25 08:51:09.978: Cause 0, Diag 114 (DTE originated/International protocol

problem)

Feb 25 08:51:09.978: Serial0/0: X.25 I R1 Clear (5) 8 lci 1

Feb 25 08:51:09.978: Cause 0, Diag 114 (DTE originated/International protocol

problem)

Feb 25 08:51:09.978: [10.22.208.2,11597/192.168.128.2,1998]: XOT O P4 Clear (5)

8 lci 1

Feb 25 08:51:09.982: Cause 0, Diag 114 (DTE originated/International protocol

problem)

Feb 25 08:51:09.982: [10.22.208.2,11597/192.168.128.2,1998]: XOT I P6 Data (28)

8 lci 1 PS 0 PR 4

Feb 25 08:51:10.034: [10.22.208.2,11597/192.168.128.2,1998]: XOT I P6 Reset Conf

irm (3) 8 lci 1

Feb 25 08:51:10.042: [10.22.208.2,11597/192.168.128.2,1998]: XOT I P6 Clear Conf

irm (3) 8 lci 1

Feb 25 08:51:10.042: Serial0/0: X.25 O R1 Clear Confirm (3) 8 lci 1

Feb 25 08:51:10.042: Serial0/1: X.25 I R1 Clear Confirm (3) 8 lci 1

Feb 25 09:59:04.236: %SYS-5-CONFIG_I: Configured from console by lrzsrab on vty0

(10.18.20.200)

XOT-GW2#

XOT-GW2#

XOT-GW2#

XOT-GW2#

XOT-GW2#

i do not really understand the message "Receive window violation" becaus my router receives PS=7 and we have modulo8, so 7 is allowed - right ???

So why has my router a problem with a packet P(S) = 7 ??

modulo 8 means from 0 to 7 right ??

thanks for any help !!

[andreas.richter]

Hi,

First of all modulo has nothing to do with window size. It seems your x.25 workstation has configured a higher layer 3 window size than your router. Cisco uses a default window size of 2. As you can see your x25 workstation sends more than two packet without waiting for an acknoledgement. Check the window-size of your workstation and then adjust the ws on your router. Important: you have to configure it incoming and outgoing:

x25 win

x25 wout

Don't try to play with figures, configure the exact values.

Andreas

[rabeder]

hi,

thanks for answer.

win=7 (out and in) means 8 pakets could be without ack - right.

i always thought modulo is the maximum numer of unacknowledged pakets ??!!!?? - anyway:

the routers have a windowsize of 7 (in/out):

the config of the router:

!

interface Serial0/2

description Verbdg. ins DATUS_X25 (f. X25 Kunden, Bankomaten,...)

bandwidth 1024

ip address 1.1.1.1 255.255.255.252

encapsulation x25

load-interval 30

x25 htc 400

x25 win 7

x25 wout 7

x25 accept-reverse

!

so winsize is configured to 7 - the admin of the workstation said that he has also a layer 3 windowsize of 7 - that´s my problem.

ps:

i receive this x25 data over a xot-cloud as you can see in the trace - could this be the problem ?

i also checked the router at the other side of the xot-cloud - it also has win=7 in/out.

any ídea ?

[andreas.richter]

Hi,

Which Interface is your workstation connected to? Seriell 0/0 or seriell 0/1?

Ask the admin which win-size is 7, layer 2 (HDLC) or layer 3 (x.25). You have to be sure that layer 3 win-size is 7. Please post a longer debug, but it seems one win size is only 4.

Andreas