The TCP address space name must be specified in the TCP system parameters data set, tcpip.TCPIP.DATA. In the data set, a "TCPIPJOBNAME TCPIP_proc" statement must be included.
The channel initiator address space must have authority to read the data set. The following techniques can be used to access your TCPIP.DATA data set, depending on which TCP/IP product and interface you are using:
You must also be careful to specify the high-level qualifier for TCP/IP correctly.
You should have a suitably configured Domain Name System (DNS) server, capable of both Name to IP Address translation and IP Address to Name translation.
For more information, see the following:
Each TCP channel when started will use TCP resources; you may need to adjust the following parameters in your PROFILE.TCPIP configuration data set:
This parameter is specified in the BPXPRMxx member of SYSI.PARMLIB. If you are using OpenEdition sockets, ensure that you specify a value large enough for your needs.
The connection name (CONNAME) field in the channel definition should be set to either the TCP network address of the target, in dotted decimal form (for example 9.20.9.30) or the host name (for example MVSHUR1). If the connection name is a host name, a TCP name server is required to convert the host name into a TCP host address. (This is a function of TCP, not WebSphere MQ.)
On the initiating end of a connection (sender, requester, and server channel types) it is possible to provide an optional port number for the connection, for example:
In this case the initiating end will attempt to connect to a receiving program listening on port 1555.
Receiving channel programs are started in response to a startup request from the sending channel. To do this, a listener program has to be started to detect incoming network requests and start the associated channel. You start this listener program with the START LISTENER command, or using the operations and control panels.
By default, the TCP Listener program uses port 1414 and listens on all addresses available to your TCP stack. You may start your TCP listener program to only listen on a specific address or hostname by specifying IPADDR in the START LISTENER command. (For more information, see Chapter 33, Preparing WebSphere MQ for z/OS for DQM with queue-sharing groups, "Listeners".)
When receiving on TCP/IP, a maximum number of outstanding connection requests is set. This can be considered a backlog of requests waiting on the TCP/IP port for the listener to accept the request.
The default listener backlog value on z/OS is 255. If the backlog reaches this values, the TCP/IP connection is rejected and the channel will not be able to start.
For MCA channels, this results in the channel going into a RETRY state and retrying the connection at a later time.
For client connections, the client receives an MQRC_Q_MGR_NOT_AVAILABLE reason code from MQCONN and should retry the connection at a later time.