OSA-Express overview

OSA-Express is an integrated hardware feature that provides direct connection to clients on local area networks (LANs). The OSA-Express feature plugs into an I/O slot just like a channel card. Fiber-optic cable connects the OSA-Express feature to the network.

OSA-Express supports direct attachment to Ethernet, token ring, and ATM LANs where clients communicate using SNA or TCP/IP. For details on using either OSA or OSA-Express for SNA, see IBM Open Systems Adapter connections between APPN nodes and Connecting two VTAMs using an external communication adapter. For details on using either OSA or OSA-Express for TCP/IP, see the z/OS Communications Server: IP Configuration Reference. For TCP/IP, OSA-Express can be configured to use IBM® Queued Direct I/O (QDIO) architecture to eliminate the need for channel control words (CCWs) and interrupts, resulting in accelerated TCP/IP data packet transmission.

OSA-Express supports QDIO for:

Gigabit Ethernet
Ethernet
ATM LAN emulation
Token ring

Ethernet links provide support for both standard Ethernet (10 Mbps) and fast Ethernet (100 Mbps).

For a summary of OSA-Express support, see Table 1.

For details on the hardware and software required to use the OSA-Express feature, see the OSA-Express customer's guide and reference in your hardware library, either zEnterprise System and System z10 OSA-Express Customer's Guide and Reference.

To use the OSA-Express feature to communicate using TCP/IP, IBM recommends defining the device to use the QDIO interface. To do this, you must code a TRL definition that contains a QDIO TRLE. To define the OSA-E for IPv4, use device type MPCIPA or interface type IPAQENET in the TCP/IP profile. To define the OSA-E for IPv6, use interface type IPAQENET6 in the TCP/IP profile.

Table 1. OSA-Express support
OSA feature	OSA mode ¹	OAT type (Input)	OAT type (Display)	VTAM® TRLE resource definition MPCLEVEL³	TCP/IP profile (device type) ²	TCP/IP profile (link type) ²	TCP/IP profile (interface type)⁴	VTAM resource definitions	NDS definitions	Protocol
OSA-Express Gigabit Ethernet	QDIO (IP) ^a	N/A	MPC (QDIO)	QDIO^k	MPCIPAⁱ	IPAQENET^j	IPAQENET^l	N/A	N/A	IP
OSA-Express ATM 155 (using TR or ENET LANE)	TCP/IP Passthru ^b	Passthru	Passthru	N/A	LCSⁱ	ETHERNet, 802.3, ETHERor802.3, IBMTR^j	N/A	N/A	N/A	IP
OSA-Express ATM 155 (using TR or ENET LANE)	SNA ^b	SNA	SNA	N/A	N/A	N/A	N/A	XCA/SWNET	N/A	SNA
OSA-Express ATM 155 (using ENET LANE)	QDIO (IP) ^c	N/A	MPC (QDIO)	QDIO	MPCIPAⁱ	IPAQENET^j	N/A	N/A	N/A	IP
OSA-Express ATM 155	HPDT ATM Native ^d	MPC	MPC	HPDT	ATMⁱ	ATM^j	N/A	N/A	N/A	IP
OSA-Express ATM 155	HPDT ATM Native ^d	MPC	MPC	HPDT	N/A	N/A	N/A	XCA/SWNET	N/A	SNA
OSA-Express FENET	TCP/IP Passthru ^e	Passthru	Passthru	N/A	LCSⁱ	ETHERNet, 802.3, ETHERor802.3^j	N/A	N/A	N/A	IP
OSA-Express FENET	SNA ^e	SNA	SNA	N/A	N/A	N/A	N/A	XCA/SWNET	N/A	SNA
OSA-Express FENET	HPDT MPC (IP) ^e	MPC	MPC (IP)	HPDT	MPCOSAⁱ	OSAENET^j	N/A	N/A	N/A	IP
OSA-Express FENET	HPDT MPC (IP) ^e	MPC	MPC (IP)	HPDT	N/A	N/A	N/A	N/A	N/A	IP
OSA-Express FENET	QDIO (IP) ^f	N/A	MPC (QDIO)	QDIO	MPCIPAⁱ	IPAQENET^j	N/A	N/A	N/A	IP
OSA-Express TR	TCP/IP Passthru ^g	Passthru	Passthru	N/A	LCS	IBMTR	N/A	N/A	N/A	IP
OSA-Express TR	SNA ^g	SNA	SNA	N/A	N/A	N/A	N/A	XCA/SWNET	N/A	SNA
OSA-Express TR	QDIO (IP) ^h	N/A	MPC (QDIO)	QDIO	MPCIPA	IPAQTR	N/A	N/A	N/A	IP
Notes: The superscripts a through h in the OSA mode column indicate which modes can run concurrently on a single OSA feature. Modes with identical superscripts can run concurrently on a single OSA feature. The superscripts i and j in the device and link type columns represent the IPv4 definitions. To define the OSA for IPv6, use the interface type IPAQENET6 in the TCP/IP profile. The superscript k in the VTAM TRLE resource definition MPCLEVEL column indicates that a VTAM TRLE is not configured for QDIO OSM interfaces or for QDIO OSX interfaces that are defined with the CHPID parameter. The superscript l in the interface type column represents IPv4 definitions that might be used as an alternative to device and link. To define the OSA for IPv6, use the interface type IPAQENET6 in the TCP/IP profile.