Browse Prior Art Database

Signal Delivery Protocol

IP.com Disclosure Number: IPCOM000120354D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Swanson, MD: AUTHOR

Abstract

In a multisystem configuration, channel to channel adapters are utilized to facilitate message passing. One goal of the message passing service is to minimize the overhead performance cost associated with insuring signals are successfully transferred between instances of the control program services.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Signal Delivery Protocol

      In a multisystem configuration, channel to channel
adapters are utilized to facilitate message passing.  One goal of the
message passing service is to minimize the overhead performance cost
associated with insuring signals are successfully transferred between
instances of the control program services.

      MVS coupling services provide the capability for multisystem
applications to send signals between instances of the provided
function.  A protocol is described which enables the MVS coupling
services component to insure successful delivery of signals across
the supported channel to channel adapters (CTCAs).

      The protocol described eliminates the need for an
acknowledgement signal to be sent from the receiving control program
to the originating control program.  The resulting reduction in
signalling traffic and complexity enhance the performance of the
multisystem signalling service provided via CTCAs.

      The use of halt subchannel to notify the sending side of a
failure eliminates the need for a signal to initiate recovery
actions.

      The way in which the control program determines if a signal has
been successfully transferred over a channel to channel adapter path
is dependent on the I/O architecture and associated implementation in
the CTCA.  I/O architecture stipulates that a channel must execute a
CCW string in the order of the channel programs contained in the
chain.  It is a violation of the architecture for a read or write
which follows a previous read or write in the same channel p...