To avoid making changes to the NCP and SSP products to support the CCL environment, CCL NCPs attached directly to VTAM® through an XCA major node are treated as though they are remote (token-ring attached) NCPs for loading purposes. To minimize the changes required in VTAM in support of CCL NCPs attached in this manner, some restrictions are imposed on how XCA-attached CCL NCPs can be loaded.

You can use the following three methods of loading an NCP:

1. Using the VTAM VARY ACT command with LOADFROM=HOST to load and activate a CCL NCP from the host.

   This method of loading an NCP is not supported for CCL NCPs attached to VTAM through an XCA major node. This is because CCL relies on the native NCP token-ring (NTRI) support, and the existing NCP product does not support loading from host over token-ring.

2. Using the VTAM VARY ACT command with LOADFROM=EXTERNAL to load and activate a CCL NCP from disk. (In the CCL environment, loading a CCL NCP from disk means using an NCP load module that has previously been saved in the Linux file system.)

   This method of loading an NCP is not supported for CCL NCPs attached directly to VTAM through an XCA major node. When this command is used to load a real 3745 over a token-ring link, another 3745 NCP is required on the other side of the token-ring link in the host direction, because this adjacent NCP plays an important role in the load and IPL operation when loading from disk.

3. Using the VTAM MODIFY LOAD command to save NCP load modules to disk and schedule the automatic load and IPL (timed IPL) of a CCL NCP.
   This method of loading an NCP is the only method supported for CCL NCPs attached directly to VTAM through an XCA major node. VTAM provides the functions necessary to:

   • Send NCP load modules from VTAM to a CCL NCP (for saving in the Linux file system).
   • Send requests to a CCL NCP to add, replace, rename, or erase NCP load modules that have been previously saved in the Linux file system.
   • Send timed IPL requests to a CCL NCP so that new or changed NCP load modules can be automatically loaded at a specified time.
   All of these functions are accomplished using existing variations of the VTAM MODIFY LOAD command. Because this command uses the SSCP-PU session to deliver these requests to the target CCL NCP, the CCL NCP must already be loaded and active (to VTAM) before issuing any of the MODIFY LOAD command variations. See the CCL product documentation for information about how to load and activate a CCL NCP for the first time.

Table 1 and Table 2 summarize the methods of loading an NCP that are supported for 3745 NCPs and CCL NCPs respectively for various types of NCP attachment. Table 1 shows what is supported for 3745 NCPs (for comparison purposes). Table 2 shows what is supported for CCL NCPs (and for 3745 NCPs when attached to VTAM through CCL NCPs). Further clarification is provided in the corresponding notes following each table.