Overview of IBM Networking
DSPU and SNA Service Point
Figure 104 ALPS Architecture
Mainframe with
airline reservation
system
Remote
router
ASCUs running ALC or UTS
| 25065 | |
| ASCUs running ALC or UTS | |
Network | Remote | |
router | ||
management system | ||
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Cisco’s ALPS feature provides an
DSPU and SNA Service Point
Downstream physical unit (DSPU) is a software feature that enables the router to function as a PU concentrator for SNA PU type 2 nodes. PU concentration at the device simplifies the task of PU definition at the upstream host while providing additional flexibility and mobility for downstream PU devices.
The DSPU feature allows you to define downstream PU type 2 devices in the Cisco IOS software. DSPU reduces the complexity of host configuration by letting you replace multiple PU definitions that represent each downstream device with one PU definition that represents the router.
Because you define the downstream PUs at the router rather than the host, you isolate the host from changes in the downstream network topology. Therefore you can insert and remove downstream PUs from the network without making any changes on the host.
The concentration of downstream PUs at the router also reduces network traffic on the WAN by limiting the number of sessions that must be established and maintained with the host. The termination of downstream sessions at the router ensures that idle session traffic does not appear on the WAN.
SNA service point support in the Cisco IOS software assumes that NetView or an equivalent product is available at the SNA host. The user interacts with the network management feature in the router and at the SNA host. In the Cisco IOS software, you can configure the host connection and show the status of this connection. At the SNA host, you can use the NetView operator’s console to view alerts and to send and receive Cisco syntax commands to the Cisco device.
Figure 105 shows a router functioning as a DSPU concentrator.
Cisco IOS Bridging and IBM Networking Configuration Guide