Configuring the Synchronous Port (B)

Port B can be set up to operate as either a synchronous port for fixed links, or an asynchronous port for dialled links. X.21, V.35 or V.24 (RS-232) links are supported. The access server automatically selects the physical interface according to the adapter cable that is connected.

Synchronous operation

Synchronous operation uses PPP over a fixed link between two networks. Before selecting synchronous operation on the Serial ports configuration page, you first need to complete fields on the Remote Sites configuration page.

1. From the IOCOMM Main menu, select Remote sites configuration and then select Create new entry.
2. Select the button towards the bottom of the page, to set Current port mode to Synchronous. This will cause the message Limiting configuration to port B to be displayed and the removal of the port table.
3. In the Remote host name text field, enter the name of a host on the network that will be reached via the fixed link. Make a note of this name; it also needs to be entered on the Serial ports configuration page. A description for the connection can be entered in the Description field if required (this entry is text only and has no operational effect). The Telephone number and Inactivity timeout fields are ignored when synchronous operation is selected.

   Remote host name	[ ] (this is a key field)
   Description	[ ]
   Telephone number	[ ]
   Inactivity timeout	[ ]

   
   Note: The Current connection type selection field is ignored when synchronous operation is selected.

   Current connection type is:

   PPP

   PPP (with Van Jacobson compression)

   SLIP

   CSLIP (SLIP with TCP header compression)

   Peer ID (username)	[ ]
   Secret (password)	[ ]
   Local IP address	[ ]
   Remote host's IP address	[ ]
   Remote host's IP netmask	[ ]

4. In the Local IP address field, enter the IP address of this IOCOMM. If you leave the field blank, the entry will default to the IP address detected at start-up. You can enter a different IP address to that of the unit (for example, where the remote end needs to talk to a specific or pre-defined IP address).
5. In the Remote host's IP address field, enter the appropriate IP address.
6. In the Remote host's IP netmask field, enter the appropriate netmask value. If no value is entered in the netmask field, the IOCOMM will default to a netmask appropriate to the remote host (i.e. a class A, B or C mask).

   In synchronous operation, the Current authentication selection is ignored and PPP is used as default.

7. When you have checked your entries on this page, select Submit to confirm. The Remote sites configuration Entry page will then be displayed and the name of the Remote site you have just configured should be listed.
8. Select Return to the main menu.
9. Select Serial ports configuration.
10. Click on Port B to enable the selection.

    Note: Synchronous operation is available on Port B only.

11. Select Physical parameters,
12. Select new mode:, select Synchronous.

    The Description field defaults to Synchronous WAN interface for synchronous operation. This is for information only.

13. In the Remote site field, enter the name as configured on the Remote sites configuration page.
14. Select Expert to display the Physical parameters expert options.
15. Select the appropriate Encoding method from the list shown (default is the first entry, which is the most common encoding method used for synchronous PPP):

    NRZ using CCITT CRC16

    NRZI using space on idle, CCITT CRC16

    NRZI using mark on idle, CCITT CRC16
    
    Check with your leased line provider on DSU/CSU setup
    
    Special wiring options are not required for synchronous operation.

16. Select Check here to reset port and make changes immediate if you wish the new settings to be effective immediately.
17. Select Submit to confirm.
18. Select Return to the main menu.

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Getting Started | Web Access | First Time Configuration Tour | Configuring DNS on IOCOMM | Changing Serial Line Configuration | Resetting a Serial Port | Using a Modem for Dial-in Operation | Outgoing Services | Disable Access | Adding a Terminal | Configuring the Synchronous Port (B) | Printing | Configuring RADIUS | Local Authentication | Dynamic Routing (RIP) | Enabling TCP Security | Global Messages | Configuring Status Logging | Telnet Service (telnetd) | Monitoring Status | Making Changes to IOCOMM