R2621 router uses X.25 to TCP to communicate with host of Siemens

Publication Date:  2012-07-27 Views:  114 Downloads:  0
Issue Description

Networking diagram: Siemens’ host-- (ser0)R2621(e0)―IP accounting host





Network description: Siemens’ host and Ser0 use X.121 address, as 111 and 222 respectively; the addresses of E0 port and IP accounting host are 1.1.1 and 2.2.2.2 respectively; we need to use X2T(X.25 to TCP) to realize direct translation between X.25 and TCP packets. The pure X.25 packets from X.25 network enquire the address translation table according to the called X.121 address, triggering to establish TCP connection for specified IP address. Once TCP connection is established, the router abstracts pure data from X.25 packets, and sends it to IP host via TCP connection, realizing the communication between IP host and X.121 address host. R2621 software version: VRP1.74-0010





Alarm Information
No



Handling Process
The following are the full configuration steps:



1. Enable X.25 switching





  [Router] x25 switching





2. Configure the interface at X.25 network side





   [Router] interface serial 0





   [Router-Serial 0] link-protocol x25 dce





   [Router-Serial 0] x25 vc-range bi-channel 8 1024





3. Configure the interface at IP network side





   [Router] interface ethernet 0





   [Router-Ethernet0] ip address 1.1.1.1 255.255.255.0





4. Configure the translation to IP network





   [Router] translate ip 1.1.1.1 port 102 pvc serial  0 1





5. Configure the translation from I to X25 network





[Router] translate x25 222 ip 1.1.1.1  port 102

Test result: it is not pure IP network, so you cannot perform ping test, but you could use transmitting files or other service communications for it. 



Root Cause
The commands required to understand:



1) Translate x25 x.121-address ip ip-address port port-number





x.121-address: X.121 address of the peer host that need to connect.





Ip: the IP address of the peer host that need to connect





Port: the port number of the peer host that need to connect





The command creates corresponding X2T configuration entry in X2T configuration table of the router to record the X121 address of the peer host, IP address, and port number.





2) translate ip ip-address port port-number  { x25 x.121-address | pvc serial interface-number pvc-number }





ip-address: the IP address of the local router





port-number: TCP port number listened by the local router





x.121-address: X.121 address of the peer destination host





interface-number: the serial port number encapsulated with x25





pvc-number: PVC number

The command creates corresponding X2T configuration entry in X2T configuration table of the router to record the IP address of the local router, number of listened port, and the X121 address of the peer destination host. Once the command is configured, the router starts to listen to the port. 



END