In the following example, which is used to define TERM1 in HOST11, TERM1 is defined to be in NET3, and its owning CDRM is HOST31.

         VBUILD TYPE=CDRSC,…
         NETWORK NETID=NET3
TERM1    CDRSC CDRM=HOST31,…

Following are some advantages of using this method:

• In a configuration with no name conflicts, this method defines the shortest session setup path. However, unless you are using NQNMODE=NQNAME, a resource, even when defined with a NETID, cannot be predefined if its name is not uniquely known in the host network. If you are using NQNMODE=NQNAME, a resource, when defined with a NETID, can be predefined even if the name is duplicated in another network.

  This method of predefining CDRSCs is designed for those systems that want to quickly locate a resource and use its real name. Therefore, the name must be uniquely known within the network in which it is defined. If the name duplicates a name in an interconnected network, it must be using its network-qualified name.

• By predefining CDRSCs in this way, you can define very specific adjacent SSCP tables. Because the NETID and, optionally, the destination SSCP are known, you can define adjacent SSCP tables for a specific NETID or NETID and SSCP name. This can eliminate the VTAM need for a default SSCP list, which might not provide the shortest session setup path.
• It adds security by restricting only authorized SSCPs to access resources in this host, assuming no dynamic CDRSCs are permitted.
• You can use NQNMODE=NQNAME to enable CDRSCs in different networks to have the same name.

Following are some disadvantages:

• If you specify the VFYOWNER=YES operand on the CDRSC definition statement, changing CDRMs in a backup situation can be complex. That is, if you have coded the CDRM operand on the CDRSC definition statement, VTAM assumes that it is the owning SSCP name. The operator must issue a MODIFY CDRM operator command in each network that contains a CDRSC definition, with the previous CDRM listed as the owner. Then (as in Figure 1), if HOST31 fails and TERM1 is acquired by HOST32 but the CDRM is not updated in HOST11, the session setup attempt fails because HOST31 is still defined as the destination of the CDRM owning the logical unit . By specifying VFYOWNER=NO on the CDRSC definition statements along the route, VTAM does not verify if that CDRM is the owner but assumes that the session request contains the backup owner and thus routes the session request to that CDRM. Then, only the operators at the session origin need to modify the CDRSC owner to the backup CDRM owner.
• If you are not using NQNMODE=NQNAME, this method does not work for interconnected networks with duplicate names. The method requires that all the connected networks have unique resource names. In many cases, renaming and predefining CDRSCs using NETID or using network-qualified names is preferable to using the alias name translation facility.