Успехи успешные))

V819#sh run
Building configuration...

Current configuration : 1395 bytes
Last configuration change at 19:10:36 UTC Sun Sep 11 2016 by cisco
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
hostname V819
boot-start-marker
boot-end-marker
no aaa new-model
no ip domain lookup
ip cef
no ipv6 cef
multilink bundle-name authenticated
license udi pid C819H-K9 sn FCZ175390TK
username cisco privilege 15 secret 4 tnhtc92DXBhelxjYk8LWJrPV36S2i4ntXrpb4RFmfqY

bstun peer-name 10.1.1.1
bstun protocol-group 1 async-generic

interface Loopback0
ip address 10.1.1.1 255.0.0.0

interface FastEthernet0
no ip address
interface FastEthernet1
no ip address
interface FastEthernet2
no ip address
interface FastEthernet3
no ip address

interface GigabitEthernet0
ip address 20.1.1.1 255.255.255.0

duplex auto
speed auto

interface Serial0
physical-layer async
no ip address
encapsulation bstun
bstun group 1
bstun route all tcp 30.1.1.1
asp role secondary
asp addr-offset 0

interface Vlan1
ip address 40.1.1.1 255.255.255.0

ip forward-protocol nd
no ip http server
no ip http secure-server

ip route 0.0.0.0 0.0.0.0 20.1.1.2

control-plane
line con 0
no modem enable
line aux 0

line 7
no activation-character
parity even
stopbits 1

line vty 0 4
login local
transport input all
scheduler allocate 20000 1000
end

V819#sh bstun
This peer: 10.1.1.1

  Serial0  (group 1 [async-generic])
route transport address         dlci lsap state      rx_pkts tx_pkts   drops
all   TCP       30.1.1.1                  open           408     401       0

-----------------------------------------------------------------------

N819#sh run
Building configuration...

Current configuration : 1785 bytes
Last configuration change at 18:43:37 UTC Sun Sep 11 2016 by cisco
version 15.5
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
hostname N819
boot-start-marker
boot-end-marker
no aaa new-model
no ip domain lookup
ip cef
no ipv6 cef
multilink bundle-name authenticated
license udi pid C819H-K9 sn FCZ1745C1BG
username cisco privilege 15 secret 4 tnhtc92DXBhelxjYk8LWJrPV36S2i4ntXrpb4RFmfqY

bstun peer-name 30.1.1.1
bstun protocol-group 1 async-generic

interface Loopback0
ip address 30.1.1.1 255.0.0.0

interface FastEthernet0
no ip address
interface FastEthernet1
no ip address
interface FastEthernet2
no ip address
interface FastEthernet3
no ip address

interface GigabitEthernet0
ip address 20.1.1.2 255.255.255.0

duplex auto
speed auto

interface Serial0
physical-layer async
no ip address
encapsulation bstun
bstun group 1
bstun route all tcp 10.1.1.1
asp role primary
asp addr-offset 0

interface Vlan1
ip address 50.1.1.1 255.255.255.0

ip forward-protocol nd
no ip http server
no ip http secure-server

ip route 0.0.0.0 0.0.0.0 20.1.1.1

line con 0
no modem enable
line aux 0

line 7
no activation-character
parity even
stopbits 1

line vty 0 4
login local
transport input all
scheduler allocate 20000 1000
end

N819#show bstun
This peer: 30.1.1.1

  Serial0  (group 1 [async-generic])
route transport address         dlci lsap state      rx_pkts tx_pkts   drops
all   TCP       10.1.1.1                  open           417     425       0

------------------------------------------------------------------------------

Проверил TestCom петлей физической и IEC Tester - работает заворот. В Hyperteminal между двумя компами текст отправлял. Но есть один момент, требующий внимания. Пока я еще не занимался настройкой размера TCP-сегмента. Он должен быть небольшим при работе с асинхронными данными, иначе большая задержка передачи будет.
C UDP не тестировал, вроде по TCP нормально работает.

А вот и проблема... я экспериментировал на 810 цисках. А если выше идти, чтобы bstun сделать нужно что DATA LICENSE была открыта.

Technology Package License Information for Module:'c2900'

-----------------------------------------------------------------
Technology    Technology-package           Technology-package
              Current       Type           Next reboot
------------------------------------------------------------------
ipbase        ipbasek9      Permanent      ipbasek9
security      None          None           None
uc            uck9          Permanent      uck9
data          None          None           None

Озадачил продавца...