Coding the HOST definition statement

The HOST definition statement in the NCP major node has a MAXBFRU operand for defining the number of buffers that the host can use for receiving data from the NCP.

If you do not define the channel in a channel-attachment major node, the MAXBFRU value on the HOST definition statement is used because the channel is implicitly defined and activated automatically when the NCP is activated.

However, when you define the channel in a channel-attachment major node,

The MAXBFRU operand on the LINE definition statement for that major node defines the number of buffers the host can use for receiving data.
VTAM® ignores the MAXBFRU value on the HOST definition statement when the link station for the channel is activated automatically. This is because the value is determined by the RNAME operand when the NCP is activated.

Recommendation: The MAXBFRU operand on the LINE definition statement of the CA definition should contain the same value as the MAXBFRU operand specified on the HOST definition statement in the NCP major node definition.

Table 1. Channel-attachment (NCP) major node definition statements and operands
Name	Definition statement	Operands	Page	Req	Sift effect	Default	Restrictions, dependencies
name	VBUILD	TYPE=CA	TYPE	R
		CONFGDS	CONFGDS
		CONFGPW	CONFGPW				CONFGDS

name	GROUP	LNCTL=NCP	LNCTL	R
		SPAN	SPAN				NetView®

name	LINE	ADDRESS	ADDRESS
		ISTATUS	ISTATUS		G	ACTIVE
		MAXBFRU	MAXBFRU		G	3
		SPAN	SPAN				NetView

name	PU	CHANCON	CHANCON		G,L	COND	LNCTL=NCP
		DELAY	DELAY		G,L	0
		ISTATUS	ISTATUS		G	ACTIVE
		MAXDATA	MAXDATA		G,L	65535	LNCTL=NCP
		PUTYPE	PUTYPE		G,L	4
		SPAN	SPAN				NetView
		TGN	TGN			1	PUTYPE=4, 5
Legend: R Required operand. G Code this operand on the higher-level GROUP definition statement to take advantage of the sift effect, or code it on this definition statement. L Code this operand on the higher-level LINE definition statement to take advantage of the sift effect, or code it on this definition statement.