Osa Dynamic Lan Idle; Osa Layer 3 Virtual Mac For Z/Os Environments; Qdio Diagnostic Synchronization; Network Traffic Analyzer - IBM z13s Technical Manual

In extending the use of adapter interruptions to OSD (QDIO) channels, the processor
utilization to handle a traditional I/O interruption is reduced. This benefits OSA-Express
TCP/IP support in z/VM, z/VSE, and Linux on z Systems.
Adapter interruptions apply to all of the OSA-Express5S and OSA-Express4S features on
z13s when in QDIO mode (CHPID type OSD).

7.3.67 OSA Dynamic LAN idle

The OSA Dynamic LAN idle parameter change helps reduce latency and improve
performance by dynamically adjusting the inbound blocking algorithm. System administrators
can authorize the TCP/IP stack to enable a dynamic setting that previously was static.
For latency-sensitive applications, the blocking algorithm is modified to be latency-sensitive.
For streaming (throughput-sensitive) applications, the blocking algorithm is adjusted to
maximize throughput. In all cases, the TCP/IP stack determines the best setting based on the
current system and environmental conditions, such as inbound workload volume, processor
utilization, and traffic patterns. It can then dynamically update the settings. OSA-Express5S
and OSA-Express4S features adapt to the changes, avoiding thrashing and frequent updates
to the OAT. Based on the TCP/IP settings, OSA holds the packets before presenting them to
the host. A dynamic setting is designed to avoid or minimize host interrupts.
OSA Dynamic LAN idle is supported by the OSA-Express5S, and OSA-Express4S features
on z13s when in QDIO mode (CHPID type OSD). It is used by z/OS V1R12 and higher
releases.

7.3.68 OSA Layer 3 virtual MAC for z/OS environments

To help simplify the infrastructure and facilitate load balancing when an LPAR is sharing an
OSA MAC address with another LPAR, each operating system instance can have its own
unique logical or virtual MAC (VMAC) address. All IP addresses that are associated with a
TCP/IP stack are accessible by using their own VMAC address instead of sharing the MAC
address of an OSA port. This situation also applies to Layer 3 mode and to an OSA port
spanned among channel subsystems.
OSA Layer 3 VMAC is supported by the OSA-Express5S and OSA-Express4S features on
z13s when in QDIO mode (CHPID type OSD). It is used by z/OS V1R12 and later.

7.3.69 QDIO Diagnostic Synchronization

QDIO Diagnostic Synchronization enables system programmers and network administrators
to coordinate and simultaneously capture both software and hardware traces. It allows z/OS
to signal OSA-Express5S and OSA-Express4S features (by using a diagnostic assist
function) to stop traces and capture the current trace records.
QDIO Diagnostic Synchronization is supported by the OSA-Express5S and OSA-Express4S
features on z13s when in QDIO mode (CHPID type OSD). It is used by z/OS V1R12 and later.

7.3.70 Network Traffic Analyzer

The z13s offers systems programmers and network administrators the ability to more easily
solve network problems despite high traffic. With the OSA-Express Network Traffic Analyzer
and QDIO Diagnostic Synchronization on the server, you can capture trace and trap data.
Chapter 7. Software support
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