10.2.4 LANSA Communications Extensions Listener Records (COMMS_LISTENER_RECS)

Configuration item COMMS_LISTENER_RECS allows the creation, change and deletion of LANSA Communications Extensions Listener Records. These records define the parameters used by the listener job when employing the listener record's communications method.

Select configuration item COMMS_LISTENER_RECS from the COMMS_EXTENSIONS group to review these records.

The screen presented looks something like this:


  LCOADMP404       Work with Communications Listener Records


   Type options, press Enter.

   2=Review/Change        4=Delete


                                    Prestart   Connection 

  Sel   Comms Method            Session Jobs   Id 

  __    SOCKET                             3   4545 








   Object /etc/dc_pgmlib/lroute.dat now locked by this job.

   F1=Help  F6=Add/Create  F12=Cancel  F14=Messages



This screen lists all the listener records stored in the LANSA Communications Extensions routing table.

Working from this screen you can, by entering one of the options beside a list entry, perform these actions:

2=Review/Change: Display the details for the listener record. From the screen displayed, press the Change function key to enable the fields to be amended.

4=Delete: Delete the listener record on which this option is entered.

Pressing the Add/Create function key will present the Add Communications Listener Record screen which allows the addition of a new listener record.


  LCOADMP411            Add Communications Listener Record


    Communications method . . . . . . . ____________________ 

    Number of session jobs to prestart  _____1 

    Connection identifier . . . . . . . ________________ 

    Cryptographic algorithm . . . . . . *NONE     +

    Data compression  . . . . . . . . . YES   

    Login timeout (seconds) . . . . . . 10

    TCP_NODELAY TCP/IP socket option  . YES

    Enable Ipv6   . . . . . . . . . . . NO

    TCP_KEEPALIVE TCP/IP socket option  YES

    Check exclusive use of port . . . . YES


   Tracing Options

     Errors . . . . . . . _ External IPC calls . _ IPC data . . . . . . _

     Debug listener . . . _ Calls to CPIC  . . . _ Internal IPC calls . _

     CPIC data  . . . . . _ System info  . . . . . Cryptographic info . _


   Logging Options  

     Connect in . . . . . _ Connect out  . . . . _ 



   F1=Help  F4=Prompt  F12=Cancel  F14=Messages



These input options are required on the Add Listener Record screen:

Communications Method

Is the communications method used by the Listener.  The communications methods supported on the IBM i by LANSA Communications Extensions are:

Number of Session Jobs to Prestart

Enter the number of session jobs to be prestarted by the listener job. Session jobs are prestarted to reduce the connection time from requesting clients by avoiding the time required by the operating system to start a job.

It must be a positive number in the range 1 to 9,999.

Note: The subsystem where the session jobs run (and the job queue where they are submitted to) must have a "maximum number of jobs active at the same time" value of at least the number entered in the "Number of Session Jobs to Prestart" field, otherwise some session jobs will stay on the job queue.


Connection Identifier

The meaning and purpose of this field is specific to each communications method:

Cryptographic Algorithm

The cryptographic algorithm used to encrypt transmitted data:

The default value is *NONE. That is, the data is not encrypted.

The use of encryption and/or compression algorithms cause more CPU cycles to be consumed during communication sessions. However this overhead is quite small when compared to other communication overheads found in most normal operational situations. 

Note: If a cryptographic algorithm is selected, the listener job will only accept connection requests from clients that support the selected cryptographic algorithm.

If you have clients that are on an earlier version of LANSA Communications Extensions (versions 1.x) which doesn't support encryption, then you can only accept connection requests from them if you select *NONE.

Press the prompt key on this field to select from the list of valid cryptographic algorithms.

Cryptographic Algorithm Selection

From this panel, you can select a cryptographic algorithm by typing its name in the input field or by positioning the cursor on the required cryptographic algorithm and pressing the Enter/record advance key.


LCOADMP410         Change Communications Listener Record                  


 Communications method . . . . . . . SOCKET                               

 Number of  .........................................................     

 Connection : LCOADMP415      Select Cryptographic Algorithm        :     

 Cryptograp :                                                       :     

 Data compr :            Cryptographic algorithm . . . . . . *NONE  :     

 Login time :                                                       :     

 TCP_NODELA : Algorithm   Description                               :     

 Enable Ipv : *NONE       No encryption                             :     

 TCP KeepAl : SSL         Secure Sockets Layer                      :     

            : DES         Data Encryption Standard (DES)            :     

            : TWF         Twofish cryptographic algorithm           :     

 Tracing Op :                                                       :     

   Errors . :                                                       : . .

   Debug li :                                               Bottom  : lls 

   CPIC dat : F1=Help  F12=Cancel  F14=Msgs                         : nfo


 Logging Options                                                          

   Connect in . . . . .      Connect out  . . . .                         



 F1=Help  F4=Prompt  F12=Cancel  F14=Msgs  F16=SelBasic    F17=Select All 

 F18=Clear All                                                            


Data Compression

Whether the transmitted data should be compressed or not:

Login Timeout

How long to wait (in seconds) for the client's login packet before timing out (Enter a value from 1 to 32 seconds).

Enable IPv6

Whether to enable support for Internet Protocol version 6.


Indicates whether the TCP_NODELAY TCP/IP socket option should be enabled or not. This option is displayed only if the communications method is SOCKET (TCP/IP). Valid values are:


Select this option to enable the TCP/IP socket option KeepAlive.

An application can request a TCP/IP provider to enable the use of keep alive packets on TCP connections by turning on the TCP_KEEPALIVE socket option. If a connection is dropped, as the result of the KEEPALIVE option, the error code 10052 is returned to any calls in progress on the socket. Any subsequent calls will fail with error code 10057. Refer to Communications Error Codes in the LANSA Communications Setup Guide for further details of these error codes.

Check Exclusive use of Port

Whether to check for exclusive use of the listener port.

Tracing Options

Check which events or actions require tracing when the listener job is running.

Refer to Tracing Options in the LANSA Communications Extensions Facility Tracing Records for the details of each option.

Logging Options

Enables the recording of normal events which need tracking when the listener job is running. On the IBM i messages are sent to the job's external message queue and will be listed in the job log.

Refer to 10.2.3 LANSA Communications Extensions Facility Tracing Records (COMMS_FACILITY_TRACE) for the details of each option.