IBM Z10 BUISNESS CLASS Z10 BC - Manual (Page 32)

Direct Memory Access (DMA)
OSA-Express3 and the operating systems share a
common storage area for memory-to-memory communi-
cation, reducing system overhead and improving perfor-
mance. There are no read or write channel programs for
data exchange. For write processing, no I/O interrupts
have to be handled. For read processing, the number of
I/O interrupts is minimized.
Hardware data router
With OSA-Express3, much of what was previously done in
fi rmware (packet construction, inspection, and routing) is
now performed in hardware. This allows packets to fl ow
directly from host memory to the LAN without fi rmware
intervention.
With the hardware data router, the “store and forward”
technique is no longer used, which enables true direct
memory access, a direct host memory-to-LAN fl ow, return-
ing CPU cycles for application use.
This avoids a “hop” and is designed to reduce latency and
to increase throughput for standard frames (1492 byte)
and jumbo frames (8992 byte).
IBM Communication Controller for Linux (CCL)
CCL is designed to help eliminate hardware dependen-
cies, such as 3745/3746 Communication Controllers,
ESCON channels, and Token Ring LANs, by providing a
software solution that allows the Network Control Program
(NCP) to be run in Linux on System z freeing up valuable
data center fl oor space.
CCL helps preserve mission critical SNA functions, such
as SNI, and z/OS applications workloads which depend
upon these functions, allowing you to collapse SNA inside
a z10 BC while exploiting and leveraging IP.
The OSA-Express3 and OSA-Express2 GbE and
1000BASE-T Ethernet features provide support for CCL.
This support is designed to require no changes to operat-
ing systems (does require a PTF to support CHPID type
OSN) and also allows TPF to exploit CCL. Supported by
z/VM for Linux and z/TPF guest environments.
OSA-Express3 and OSA-Express2 OSN (OSA for NCP)
OSA-Express for Network Control Program (NCP), Channel
path identifi er (CHPID) type OSN, is now available for use
with the OSA-Express3 GbE features as well as the OSA-
Express3 1000BASE-T Ethernet features.
OSA-Express for NCP, supporting the channel data link
control (CDLC) protocol, provides connectivity between
System z operating systems and IBM Communication Con-
troller for Linux (CCL). CCL allows you to keep your busi-
ness data and applications on the mainframe operating
systems while moving NCP functions to Linux on System z.
CCL provides a foundation to help enterprises simplify
their network infrastructure while supporting traditional
Systems Network Architecture (SNA) functions such as
SNA Network Interconnect (SNI).
Communication Controller for Linux on System z (Program
Number 5724-J38) is the solution for companies that
want to help improve network availability by replacing
32