When scaling the SNASw function to hundreds or thousands of nodes, many network administrators find
that defining a unique control point (CP) name on each node provides unnecessary configuration
overhead. Dynamic CP name generation offers the ability to use the Cisco IOS hostname as the SNA CP
name or to generate a CP name from an IP address. These facilities reuse one SNASw configuration
across many routers and eliminate the specific configuration coordination previously required to
configure a unique CP name for each SNA node in the network. Administrators can still explicitly
configure the CP name within the SNASw configuration.

Dynamic SNA BTU Size

Most SNA node implementations require specific tuning of the SNA basic transmit unit (BTU) in the
configuration. SNASw analyzes the interface maximum transfer units (MTUs) of the interfaces it uses
and dynamically assigns the best MTU values for that specific port. For served dependent PU 2.0
devices, SNASw uses the downstream MAXDATA value from the host and dynamically sets the SNA
BTU for that device to the MAXDATA value.

DLUR Connect-Out

SNASw can receive connect-out instructions from the IBM Communications Server for S/390. This
function allows the system to dynamically connect-out to devices that are configured on the host with
the appropriate connect-out definitions. This feature allows connectivity to SNA devices in the network
that were traditionally configured for connect-out from the host.

Note

DLUR connect-out can be performed over any supported data-link type.

Responsive Mode Adaptive Rate-Based Flow Control

Early HPR implementations failed to perform well in environments subject to packet loss (for example,
Frame Relay, IP transport) and performed poorly when combined with other protocols in multiprotocol
networks. SNASw implements the second-generation HPR flow control architecture, called Responsive