Appendix F.

RSF Broadcast Support

An efficient way to send objects and data from one machine to many others is to send the transmission as a broadcast.  When you use RSF to send a broadcast transmission, the data is sent once and read by many receiver machines simultaneously.  Thus you can send a transmission to hundreds of machines in about the time it takes to transmit to a single machine.

RSF's broadcast support is based on TCP/IP multicast technology.  On top of this, RSF adds integrity logic to help ensure that the entire transmission is received by all recipients.

Requirements

• RSF release 7.2 or later must be installed on the sending and on all receiving machines.
   
• Broadcasts can only be sent over TCP/IP networks.
   
• If the broadcast is to be sent across a wide area network, the routers and switches tying the network together must be multicast capable and must be configured to enable multicast transmissions.  Most modern routers, such as those manufactured by Cisco and others, support multicast.

Receiver Machine Setup

Follow these steps on each machine that will be receiving the broadcast.

1. Use the Change RSF Defaults (CHGRSFDFT) command (RSF menu option 31) to set the Default Server ID for this machine.  This parameter can be found toward the end of the defaults.  Enter the ID that the sending machine uses to contact this one. This should match the value specified for server ID in the entry that points to this machine, in the server directory of the sending machine.

2. Start the RSF Server Function with the STRRSFSRV command or RSF menu option 21.  You do not need to start the RSF SDLC nor PPP servers, but it will cause no harm if you do.  The recommended parameters are shown below:

The value you specify here for "Broadcast Port to Monitor" must match the value that is specified in the *BROADCAST server ID on the sending machine.  (See below.)

The same is true for the "Broadcast Group Address".  A valid multicast group address must be in the range of 224.0.0.0 to 232.255.255.255.  Note: Addresses from 224.0.0.0 to 224.0.0.255 are intended for intra-network transmissions and are not typically forwarded by multicast-capable routers. See RFC1700 for a list a list of reserved multicast group addresses.

The value you specify for "Broadcast Interface Address" should match the IP address for the interface on this machine that accesses the network.  This is typically the IP address associated with the Ethernet card.  You can view the choices by selecting option 1 from the OS/400 CFGTCP menu.

3. Confirm that the RSF broadcast server is active by running the command
   
     WRKACTJOB  JOB(RS*)
   
   You should see job RSFSRVTCM_ listed.

Sender Machine Setup

Follow these steps on the machine that will be sending broadcasts.

1. Use the Add Server Directory Entry (ADDRSFSDE) command to define a new server.  Specify *BROADCAST for "Connection Method".  The other recommended parameters are shown below.

Enter some meaningful value for "my_server".

The value you specify here for "Broadcast Port" must match the value that is specified for "Broadcast port to monitor" when starting the RSF broadcast server on the receiving machines.  (See above.)

Similarly, the value you enter for "Broadcast Group Address" much match the value specified when starting the RSF broadcast server on the receiving machines.

The value you specify for "Broadcast Interface Address" should match the IP address for the interface on this machine that accesses the network. This is typically the IP address associated with the Ethernet card.  You can view the choices by selecting option 1 from the OS/400 CFGTCP menu.

2. Start the RSF Server Function with the STRRSFSRV command or RSF menu option 21. You do not need to start the RSF SDLC nor PPP servers, but it will cause no harm if you do. See above for the recommended parameters.

3. Confirm that the RSF broadcast server is active by running the command
   
     WRKACTJOB JOB(RS*)
   
   You should see job RSFSRVTCM_ listed.

Broadcasting Objects and Data

Once you have completed the broadcast setup on the source and target machines, you can send a broadcast by simply running one of the following commands, specifying a server ID that has *BROADCAST defined for "Connection Method."

Send Object (SNDOBJRSF)
Send Library (SNDLIBRSF)
Send IFS Objects (SNDIFSRSF)
Send Package (SNDRSFPKG)

If you would like to receive feedback indicating which machines received the transmission, do the following on the sending machine:

1. Use the WRKRSFSRV command or option 1 on the RSF menu to work with the list of RSF servers.  Make sure there is a server entry for each remote machine that you expect to receive the broadcast.  If necessary, you can use the F6 key to add additional entries.  Each server ID name used here should match the value specified on the corresponding target machine for "Default Server ID".  (See above.)  To make the next step easier, you may want to include a special character code in the text of each of these server entries.
   
   Note: Connection information entered for these server entries will not be used for broadcasts.

2. Create an RSF Location List with the CRTRSFLL command.  Be sure to store the list in a a library that can be accessed by profile RSFSRV in batch.  Include the server ID for each receiver machine in the list.

3. Now, when using one of the SNDxxx commands listed above to initiate a broadcast, press F9 to see all parameters and enter the qualified name of your location list.  RSF will then update the list automatically as responses are received.  You can use the Display Location List (DSPRSFLL) command at any time to see the current status of entries in the list.