Supported communications protocols for remote journals

The remote journal function supports the following communications protocols for replicating the journal entries to the remote systems:

  • OptiConnect for IBM® i. If you want to use the OptiConnect for IBM i support, you must purchase and install the required hardware and software for that support. Refer to OptiConnect for IBM i for more information.
  • Systems Network Architecture (SNA). If you want to use SNA for the transport, there are no additional software considerations. The software support is in the base operating system. You must purchase whatever hardware is appropriate for your configuration. For more information, see the SNA Distribution Services manual in the IBM Publications Center at http://www.elink.ibmlink.ibm.com/publications/servlet/pbi.wss? .
  • Transmission Control Protocol/Internet Protocol(TCP/IP). If you want to use TCP/IP for the transport, there are no additional software considerations. The software support is in the base operating system. You must purchase whatever hardware is appropriate for your configuration.
    Note: All remote journal TCP connections use the TCP local port of 3777.
  • Data port. Allows you to run remote journal over a cluster and specify up to four lines of communication, allowing for greater resiliency.
  • Sockets (IPv6). Allows you to run remote journal over a Sockets IPv6 TCP/IP connection.
    Note: All remote journal Sockets IPv6 connections use the TCP local port of 3888.
  • Secure Sockets (SSL). Allows you to run remote journal over a Secure Sockets TCP/IP connection.
    Note: All remote journal Secure Sockets connections default to using the TCP local port of 3889. If you want remote journal Secure Sockets connections to use a different port, you can remove the rmtjournal-ssl service table entry and add a rmtjournal-ssl service table entry with the port you want on both the source and target system using the WRKSRVTBLE command. Using Secure Sockets incurs a larger performance impact compared with any of the other supported communication protocols. The performance impact of Secure Sockets is dependent on the level of cipher/protocol chosen when configuring the remote journal application ID (QIBM_QJO_RMT_JRN_SRC and QIBM_QJO_RMT_JRN_TGT) using Digital Certificate Manager (DCM). For information on setting up SSL, see the configuring DCM topic Configuring DCM

Specifying a relational database (RDB) directory entry identifies the communications protocol that the remote journal function uses. The RDB that is specified must meet the following rules:

  • The communications protocol must be one of the remote journal function supported protocols.
  • The remote location name in the RDB cannot refer to the *LOCAL database.
  • The RDB cannot use an application requester driver program (*ARDPGM) to locate the target system.
  • When TCP communications are being used to connect to an independent disk pool, the Relational Database (RDB) entry to the independent disk pool must have the Relational database value set to the target system's local RDB entry and the relational database alias value set to the independent disk pool's name.

For more information about creating relational databases, refer to the Distributed Database Programming topic.

Security of the remote journal function is dependent on the communications protocol security. The remote journal function does not alter the security characteristics that are available.

When sending data to the target system using TCP (IPV4) or Sockets (IPV6) remote journal uses the greater value of 256 KB, or the size specified on CHGTCPA for TCP send buffer size (TCPSNDBUF) on the source system, or TCP receive buffer size (TCPRCVBUF) on the target system.

Implementing a Virtual Private Network (VPN) should provide a secure solution for the traffic between the VPN client and server in your remote journal environment. While VPN does not preclude data interception, use of VPN encryption does prevent the intercepted data from being interpreted or deciphered.

The communications function that is identified by the RDB can be shared by other activity. However, you may consider isolating the remote journal function activity in order to have the best performance.