Title: DECbrouter90 example of CMNS (CONS) over LLC2

Product: DECbrouter90 V9.14 or V10.x

Keyword:

Question: How do I configure the DECbrouter90 to support LLC2 for X.25
          encapsulation of OSI packets across a LAN?

Solution:

        This is an example Connection Mode Network Service (CMNS) configuration
for the DECbrouter 90. CMNS or CONS is a method for transferring OSI datagrams 
over an ethernet from a host running the OSI protocol to a DECbrouter90 via 
X.25 encapsulation.


        -------------
        | HOST NEIL |  MAC address 0800.2B35.A62E
        | OSI host  |  NSAP address 37.1234.5678.9012.3400.4608.002B.35A6.2E21
        | running   |
        |   OSI     |
        |Application|
        | over LLC2 |
        -------------
              |         Ethernet
        --------------------------------------------
                      | 
                      | E0
 ------------------------------------------------------------------------
 |                              DECbrouter 90                           |
 |hostname BRUTG                                                        |
 |!                                                                     |
 |interface Ethernet 0                                                  |
 |!                                                                     |
 |!enables llc2 on this interface                                       |
 |!                                                                     |
 |cmns enable                                                           |
 |!                                                                     |
 |!maps X.25 calls received on any other interface containing a called  |
 |!address extension NSAP of 37.1234.5678.9012.3400.4608.002B.35A6.2E21 |
 |!to be forwarded to MAC address 0800.2B35.A62E over LLC2.             |
 |!                                                                     |
 |x25 map CMNS 37.1234.5678.9012.3400.4608.002B.35A6.2E21 0800.2B35.A62E|
 |!                                                                     |
 |!set the local-window size to the same as VMS and Ultrix 127          |
 |!                                                                     |
 |llc2 local-window 127                                                 |
 |!                                                                     |
 |!interface connecting to the PSDN                                     |
 |!                                                                     |
 |interface Serial 0                                                    |
 |!                                                                     |
 |!set for X.25 encapsulation, DTE mode is the default. Depending upon  | 
 |!what PSDN you are connecting to you may have to set various timers,  |
 |!window & data sizes and various other parameters.                    |
 |!                                                                     |
 |encapsulation X25                                                     |
 |!                                                                     |
 |!X.121 address assigned by PSDN, your DTE address.                    |
 |!                                                                     |
 |x25 address 333333333333                                              |
 |!                                                                     |
 |!maps X.25 calls received on any other interface containing a called  |
 |!address extension NSAP of 37.1234.5678.9012.3400.4508.002B.35B6.6921 |
 |!to be forwarded to DTE address 222222222222 over the PSDN connection |
 |!                                                                     |
 |!x25 map CMNS 37.1234.5678.9012.3400.4508.002B.35B6.6921 222222222222 |
 ------------------------------------------------------------------------
                      \ S0
                      /  
                      \ (X.25 encapsulation running over leased line or PSDN)
                      / 
                      \ S0
 ------------------------------------------------------------------------
 |                              DECbrouter 90                           |
 |hostname BRUTG                                                        |
 |!                                                                     |
 |interface Ethernet 0                                                  |
 |!                                                                     |
 |!enables llc2 on this interface                                       |
 |!                                                                     |
 |cmns enable                                                           |
 |!                                                                     |
 |!maps X.25 calls received on any other interface containing a called  |
 |!address extension NSAP of 37.1234.5678.9012.3400.4508.002B.35B6.6921 |
 |!to be forwarded to MAC address 0800.2B35.B669 over LLC2.             |
 |!                                                                     |
 |x25 map CMNS 37.1234.5678.9012.3400.4508.002B.35B6.6921 0800.2B35.B669|
 |!                                                                     |
 |!set the local-window size to the same as VMS and Ultrix 127          |
 |!                                                                     |
 |llc2 local-window 127                                                 |
 |!                                                                     |
 |!interface connecting to the PSDN                                     |
 |!                                                                     |
 |interface Serial 0                                                    |
 |!                                                                     |
 |!set for X.25 encapsulation. Depending upon what PSDN you are         |
 |!connecting to you may have to set various timers, window & data      |
 |!sizes and various other parameters.                                  |
 |!                                                                     |
 |encapsulation X25-dce                                                 |
 |!                                                                     |
 |!X.121 address assigned by PSDN, your DTE address.                    |
 |!                                                                     |
 |x25 address 222222222222                                              |
 |!                                                                     |
 |!maps X.25 calls received on any other interface containing a called  |
 |!address extension NSAP of 37.1234.5678.9012.3400.4608.002B.35A6.2E21 |
 |!to be forwarded to DTE address 333333333333 over the PSDN connection |
 |!                                                                     |
 |x25 map CMNS 37.1234.5678.9012.3400.4608.002B.35A6.2E21 333333333333  |
 ------------------------------------------------------------------------
                      | E0
                      |         Ethernet
        --------------------------------------------
              | 
        -------------
        |HOST CLAPTN|
        | OSI host  | MAC address 0800.2B35.B669
        | running   | NSAP address 37.1234.5678.9012.3400.4508.002B.35B6.6921
        |   OSI     |
        |Application|
        | over LLC2 |
        -------------