Table of Contents Addressing Particularities

5.3 The IBM High-Performance Parallel Interface (HIPPI)

The IBM High-Performance Parallel Interface (HIPPI) is an 800 Mbps data transfer device that operates in a variety of high-speed computer environments. It is an implementation of the ANSI X3.183-1991 High-Performance Parallel Interface (HIPPI-PH) standard.

The IBM HIPPI can attach devices that comply with the ANSI standard to selected members of the IBM Enterprise System/3090 (ES/3090) and IBM Enterprise System/9000 (ES/9000) family of computers. Some examples of these devices are high-resolution real-time visualization devices, file servers, workstations or supercomputers.

5.3.1 Implementations

5.3.1.1 MVS

One of the following hardware RPQs is required for the HIPPI-supported ES/3090 or ES/9000 family of computers: 8P1347, 8P1348, 8P1353 or 8P1354.

The HIPPI software (RPQ P88039, program number 5799-DKW) makes the function of the HIPPI available to the HIPPI application programs. MVS TCP/IP V3R1 is one such program.

The IBM HIPPI software actually provides both a high-level, multiplexing interface and a low-level, exclusive-use interface. Basically, the high-level multiplexed interface gives several applications the ability to use HIPPI at the same time. This interface complies with the ANSI HIPPI-FP framing protocol. The low-level, exclusive-use interface allows only a single application to establish an association with it.

Note: MVS TCP/IP V3R1 was implemented to use the low-level interface. This means that other software may not use HIPPI while MVS TCP/IP is using it.

Please see Figure - IBM HIPPI and MVS TCP/IP for an overview of the relationship of the various components.


Figure: IBM HIPPI and MVS TCP/IP

5.3.2 HIPPI Draft Standards and Internet-Draft

The ANSI X3T9.3 HIPPI working group drafted four standards covering:

• (HIPPI-PH) the physical and electrical specification
• (HIPPI-FP) the framing protocol of a point-to-point interface
• (HIPPI-LE) the encapsulation of IEEE 802.2 LLC data packets
• (HIPPI-SC) the control of HIPPI physical layer switches

Please see Figure - Relationship of ANSI HIPPI Draft Standards for an overview of the relationship of the various ANSI draft standards.


Figure: Relationship of ANSI HIPPI Draft Standards

The Internet-Draft "IP and ARP on HIPPI" by A. Nicholson, June 1992, describes the HIPPI interface between a host and a crosspoint switch that complies with the HIPPI-SC draft standard. This is a working draft which is intended to become an Internet standard in the future.

Note: The HIPPI-SC switches are devices which allow a single HIPPI device to switch between multiple HIPPI devices without involving protocols above the HIPPI-PH layer.

5.3.3 Relationship of IBM HIPPI and the ANSI Draft Standards

The current IBM HIPPI does not support two items in the ANSI draft standard X3.183-1991 (HIPPI-PH):

• The IBM HIPPI does not support microbursts. Data is exchanged in packet sizes that are integral multiples of 4096 bytes.
• The IBM HIPPI does not have a means for software to deactivate the REQUEST signal of the IBM outbound channel once a program activates REQUEST by setting the clear bit in the outbound control word.

Table of Contents CTC (Channel To Channel)