A migration data host resides on the periphery of a combined APPN and subarea network. A migration data host combines the function of an end node with the function and role of a subarea data host.

Like a data host in a subarea network, a migration data host is dedicated to processing application programs and does not control network resources. It also participates as a cross-domain resource manager (CDRM) in the subarea network. The migration data host also functions as an end node in the APPN network. All of the characteristics previously described for end nodes apply to migration data hosts.

To enable the migration data host to participate in the subarea network, it is defined with a unique subarea number and supports subarea path definition statements.

The migration data host communicates network control data by using SSCP-SSCP sessions with other subarea nodes and CP-CP sessions with its network node server. It can be connected to other APPN nodes, LEN nodes, and subarea nodes. A migration data host can perform intermediate routing in either a subarea network or an APPN network, but it is not recommended. However, its locally attached LEN nodes and dependent LUs can establish sessions with resources in other APPN or subarea domains.