Есть Cisco 2610 2х Serial, 1x Ethernet
К Serial-ам подключен модем Nokia DNT 128
Где-то за Модемами 2х X.25 PVC (что и как конкретно настроено не знаю)
на Cisco настроена tcp-x25 трансляция
Почему-то раз в 900 секунд рвется Se0/1 PVC
Глубокие копания показали непонятное "TTY66: create timer type 2, 900 second"
Объясните, пожалуйста, что за таймер и как его отключить?

лог дебаггинга:
2600#sh debugging
General OS:
  Modem control/process activation debugging is on
X.29 PAD:
  X25 PAD debugging is on
X.25:
  X.25 special event debugging is on
Protocol translation:
  Protocol Translation debugging is on
18:42:25: TTY66: timer type 2 expired
18:42:25: TTY66: Session timer callback
18:42:25: TTY66: Session-timeout expired
2600#
18:42:30: PAD: Connection closed Cause: 29 Diag: 115
18:42:30: Serial0/1: X.25 O D1 Reset (5) 8 lci 1
18:42:30:   Cause 0, Diag 115 (DTE originated/International link out of order)
18:42:30: PAD66: Closing connection to .  In 20205/425, out 0/0
18:42:30: freepcb80C9EB0C: packets on input queue
18:42:30: TTY66: Line reset by "TCP to PAD"
18:42:30: TTY66: Modem: (unknown)->READY
18:42:30: TTY66: destroy timer type 0
18:42:30: TTY66: destroy timer type 1
18:42:30: TTY66: destroy timer type 3
18:42:30: TTY66: destroy timer type 4
18:42:30: TTY66: destroy timer type 2 (OK)
18:42:30: tcppad67: conntop not alive
18:42:30: tcppad70: fork started
2600#
18:42:30: TTY70: create timer type 2, 900 seconds
18:42:30: Serial0/1: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:30: Serial0/1: X.25 I D1 Reset (5) 8 lci 1
18:42:30:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
18:42:30: PAD70: statbits set to CARDROP
18:42:30: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:30: Serial0/1: X.25 O D3 Reset Confirm (3) 8 lci 1
18:42:31: TTY67: timer type 2 expired
18:42:31: TTY67: Session timer callback (continued in 861)
2600#
18:42:35: PAD: Connection closed Cause: 29 Diag: 115
18:42:35: Serial0/0: X.25 O D1 Reset (5) 8 lci 1
18:42:35:   Cause 0, Diag 115 (DTE originated/International link out of order)
18:42:35: PAD67: Closing connection to .  In 255/21, out 177/12
18:42:35: TTY67: Line reset by "TCP to PAD"
18:42:35: TTY67: Modem: (unknown)->READY
18:42:35: TTY67: destroy timer type 0
18:42:35: TTY67: destroy timer type 1
18:42:35: TTY67: destroy timer type 3
18:42:35: TTY67: destroy timer type 4
18:42:35: TTY67: destroy timer type 2 (OK)
18:42:35: PAD: Connection closed Cause: 29 Diag: 115
18:42:35: Serial0/1: X.25 O D1 Reset (5) 8 lci 1
18:42:35:   Cause 0, Diag 115 (DTE originated/International link out of order)
18:42:35: PAD70: Closing connection to .  In 0/1, out 0/0
18:42:35: freepcb80C9EB0C: packets on input queue
18:42:35: TTY70: Line reset by "TCP to PAD"
18:42:35: TTY70: Modem: (unknown)->READY
18:42:35: TTY70: destroy timer type 0
18:42:35: TTY70: destroy timer type 1
18:42:35: TTY70: destroy timer type 3
18:42:35: TTY70: destroy timer type 4
18:42:35: TTY70: destroy timer type 2 (OK)
18:42:35: Serial0/0: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:35: Serial0/0: X.25 I D1 Reset (5) 8 lci 1
18:42:35:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
2600#
18:42:35: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:35: Serial0/0: X.25 O D3 Reset Confirm (3) 8 lci 1
18:42:35: Serial0/1: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:35: Serial0/1: X.25 I D1 Reset (5) 8 lci 1
18:42:35:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
18:42:35: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:35: Serial0/1: X.25 O D3 Reset Confirm (3) 8 lci 1
18:42:35: tcppad66: fork started
18:42:35: TTY66: create timer type 2, 900 seconds
2600#
18:42:36: tcppad66: conntop not alive
18:42:37: PAD: Corresponding connection not established Cause: 29 Diag: 113
18:42:37: Serial0/1: X.25 O D1 Reset (5) 8 lci 1
18:42:37:   Cause 0, Diag 113 (DTE originated/Remote network problem)
18:42:37: PAD0: connection is not available, discard packet
2600#
18:42:37: Serial0/1: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:37: Serial0/1: X.25 I D1 Reset (5) 8 lci 1
18:42:37:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
18:42:37: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:37: Serial0/1: X.25 O D3 Reset Confirm (3) 8 lci 1
2600#
18:42:40: PAD: Corresponding connection not established Cause: 29 Diag: 113
18:42:40: Serial0/1: X.25 O D1 Reset (5) 8 lci 1
18:42:40:   Cause 0, Diag 113 (DTE originated/Remote network problem)
18:42:40: PAD0: connection is not available, discard packet
18:42:40: tcppad67: fork started
18:42:40: TTY67: create timer type 2, 900 seconds
18:42:40: Serial0/1: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:40: Serial0/1: X.25 I D1 Reset (5) 8 lci 1
18:42:40:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
18:42:40: PAD67: statbits set to CARDROP
18:42:40: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:40: Serial0/1: X.25 O D3 Reset Confirm (3) 8 lci 1
2600#
18:42:41: PAD: Connection closed Cause: 29 Diag: 115
18:42:41: Serial0/0: X.25 O D1 Reset (5) 8 lci 1
18:42:41:   Cause 0, Diag 115 (DTE originated/International link out of order)
18:42:41: PAD66: Closing connection to .  In 0/0, out 0/0
18:42:41: TTY66: Line reset by "TCP to PAD"
18:42:41: TTY66: Modem: (unknown)->READY
18:42:41: TTY66: destroy timer type 0
18:42:41: TTY66: destroy timer type 1
18:42:41: TTY66: destroy timer type 3
18:42:41: TTY66: destroy timer type 4
18:42:41: TTY66: destroy timer type 2 (OK)
18:42:41: Serial0/0: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:41: Serial0/0: X.25 I D1 Reset (5) 8 lci 1
2600#
18:42:41:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
18:42:41: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:41: Serial0/0: X.25 O D3 Reset Confirm (3) 8 lci 1
2600#
18:42:45: PAD: Connection closed Cause: 29 Diag: 115
18:42:45: Serial0/1: X.25 O D1 Reset (5) 8 lci 1
18:42:45:   Cause 0, Diag 115 (DTE originated/International link out of order)
18:42:45: PAD67: Closing connection to .  In 0/2, out 0/0
18:42:45: freepcb80C9EB0C: packets on input queue
18:42:45: TTY67: Line reset by "TCP to PAD"
18:42:45: TTY67: Modem: (unknown)->READY
18:42:45: TTY67: destroy timer type 0
18:42:45: TTY67: destroy timer type 1
18:42:45: TTY67: destroy timer type 3
18:42:45: TTY67: destroy timer type 4
18:42:45: TTY67: destroy timer type 2 (OK)
18:42:45: Serial0/1: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:45: Serial0/1: X.25 I D1 Reset (5) 8 lci 1
2600#
18:42:45:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
18:42:45: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:45: Serial0/1: X.25 O D3 Reset Confirm (3) 8 lci 1
18:42:46: tcppad66: fork started
18:42:46: TTY66: create timer type 2, 900 seconds
2600#
18:42:47: tcppad66: conntop not alive
2600#
18:42:49: PAD: Corresponding connection not established Cause: 29 Diag: 113
18:42:49: Serial0/1: X.25 O D1 Reset (5) 8 lci 1
18:42:49:   Cause 0, Diag 113 (DTE originated/Remote network problem)
18:42:49: PAD0: connection is not available, discard packet
18:42:49: Serial0/1: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:49: Serial0/1: X.25 I D1 Reset (5) 8 lci 1
18:42:49:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
18:42:49: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:49: Serial0/1: X.25 O D3 Reset Confirm (3) 8 lci 1
18:42:49: PAD: Corresponding connection not established Cause: 29 Diag: 113
18:42:49: Serial0/1: X.25 O D1 Reset (5) 8 lci 1
2600#
18:42:49:   Cause 0, Diag 113 (DTE originated/Remote network problem)
18:42:49: PAD0: connection is not available, discard packet
18:42:50: Serial0/1: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:50: Serial0/1: X.25 I D1 Reset (5) 8 lci 1
18:42:50:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
18:42:50: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:50: Serial0/1: X.25 O D3 Reset Confirm (3) 8 lci 1
2600#
18:42:51: tcppad67: fork started
18:42:51: TTY67: create timer type 2, 900 seconds
18:42:52: PAD: Connection closed Cause: 29 Diag: 115
18:42:52: Serial0/0: X.25 O D1 Reset (5) 8 lci 1
18:42:52:   Cause 0, Diag 115 (DTE originated/International link out of order)
18:42:52: PAD66: Closing connection to .  In 0/0, out 0/0
18:42:52: TTY66: Line reset by "TCP to PAD"
18:42:52: TTY66: Modem: (unknown)->READY
18:42:52: TTY66: destroy timer type 0
18:42:52: TTY66: destroy timer type 1
18:42:52: TTY66: destroy timer type 3
18:42:52: TTY66: destroy timer type 4
18:42:52: TTY66: destroy timer type 2 (OK)
2600#
18:42:52: Serial0/0: X.25 I D2 Reset Confirm (3) 8 lci 1
18:42:52: Serial0/0: X.25 I D1 Reset (5) 8 lci 1
18:42:52:   Cause 0, Diag 250 (DTE originated/Unknown diagnostic)
18:42:52: PAD: X25 VC reset Cause: 0 Diag: 250
18:42:52: Serial0/0: X.25 O D3 Reset Confirm (3) 8 lci 1
2600#
18:42:57: tcppad66: fork started
18:42:57: TTY66: create timer type 2, 900 seconds