TPF Announces Support of Cisco 7500 Series Routers
by Dan Yee, IBM TPF Development
When TPF development provided TPF Transmission Control Protocol/lnternet Protocol (TCP/IP) support last year, an offload device such as the IBM 3172 Interconnect Controller Model 3 was required for the processing of the socket application programming interface (API) functions. Today, an offload device is still required for the processing of the socket API functions, but you now have the option of using one of the Cisco 7500 series routers as your offload device. If you intend to use a Cisco router, you must be at TPF Version 4.1, program update tape (PUT) level 6, and you must apply APAR PJ24746. If you now use Cisco 75xx router, you must upgrade your channel interface processor (CIP) microcode to enable your Cisco router to connect to the TPF system. The general release of the modified CIP microcode that is you need to connect to the TPF system is currently in final test and will be available in September.
Although TPF TCP/IP code changes were needed to support connectivity to the Cisco 7500 series routers, most of the changes will be transparent to you. After you apply APAR PJ24746, you will notice that a new console message will be displayed when any offload device is connected to the system either during system cycle-up or through a ZCLAW ACT functional message in computer room agent set (CRAS) state or above. This console message (CLAW00741), which indicates that a Common Link Access to Workstation (CLAW) protocol (offload) device has been connected to the TPF system, actually is not new because the message was added to the system when TPF TCPIIP support was added last year. Most likely, you have not seen the message if you have been using an IBM 3172 Interconnect Controller Model 3 as your offload device because, with the IBM 3172, we designed the system to only issue a CONNECTED message when the offload device initiated a connection request. Because the 3172 typically does not initiate the connection request, message CLAW00741 was not displayed to the console. Because the Cisco router initiates the connection request, message CLAW00741 is now displayed on the console when the TPF system accepts the connection. With APAR PJ24746, we have chosen to issue CONNECTED message CLAW00741 when an IBM 3172 Interconnect Controller Model 3 is connected to the TPF system as well, so you should now see that message on the console for both the IBM 3172 and the Cisco router.
Another change you will notice after you apply APAR PJ24746 is the appearance of message CLAW0072E on the console whenever a CLAW (offload) device is disconnected from the TPF system. In the past, this message was displayed only when the offload device initiated the disconnect request. Now that the TPF system issues a CONNECTED message when TPF and the offload device initiate the connect request, we have chosen to issue a DISCONNECTED message when TPF and the offload device initiate a disconnect request. This message will be displayed whenever you enter a ZCLAW INACT message in CRAS state or above, or during system cycle-down when one or more offload devices are connected to the TPF system.
Other code changes for APAR PJ24746, which will be transparent to you, were made to ensure compatibility between the IBM 3172 Interconnect Controller Model 3 and the Cisco 7500 series routers.
If you consider using a Cisco 7500 series router as your offload device and would like additional information about the router, see a Cisco sales representative or your IBM TPF client support representative.